{"paper_id":"2a9bd72d-ebe5-4f32-8652-df85466a33b1","body_text":"Cyclopogon Guayanensis is an Unusual Orchid With a Generalistic Pollination System and Hexose Dominant Nectar | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Cyclopogon Guayanensis is an Unusual Orchid With a Generalistic Pollination System and Hexose Dominant Nectar THIAGO E. C. MENEGUZZO, SUELI M. GOMES, JOÃO A. N. BATISTA, ANTONIO J. C. AGUIAR, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4876023/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 May, 2025 Read the published version in Journal of Chemical Ecology → Version 1 posted 8 You are reading this latest preprint version Abstract Cyclopogon is a large Neotropical orchid genus pollinated by halictid bees that offers nectar as reward. In a recent phylogenetic tree, Brachystele guayanensis emerged nested within Cyclopogon and was transferred to that genus. The hypothesis for this study was that C. guayanensis would show a similar floral biology to Cyclopogon , although distinctive in its small, congested white flowers. Data on floral biology, pollinators, micromorphology, histochemistry, and nectar sugar composition of C. guayanensis in the Distrito Federal, Brazil were gathered. C. guayanensis is pollinated by at least four species of bees belonging to genera Exomalopsis , Nomada , Tetrapedia (Apidae) and Dialictus (Halictidae) foraging for nectar. Nectar is produced in visually imperceptible quantities by papillae on the inner surface of the labellum; similar papillae occur in other species of Cyclopogon but nectar class is unknown. C. guayanensis nectar is hexose dominant (< 10% sucrose) in the Baker and Baker system and is the second record of this nectar class in the Orchidaceae. Pollinia are dorsally adhesive and probably attach to the underside of the bee labrum, as in other Cyclopogon . The inflorescence rachis, bracteoles, and outer surfaces of the base of the sepals are covered with lipid-secreting glandular trichomes; sepals and petals have numerous raphid-rich idioblasts. This is the first record of papillae on a spurless labellum shown to produce nectar in the Orchidoideae. We suggest that hexose dominant nectars in the Orchidaceae are associated with a geophytic habit, small pale flowers, exposed nectaries, visually imperceptible quantities of nectar, and a generalistic pollination system, and coin the term ‘modest pollination strategy’ for this syndrome. Apidae floral histochemistry Halictidae hexose nectar raphids Spiranthinae Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction The Pelexia alliance (subtribe Spiranthinae, tribe Cranichideae, subfamily Orchidoideae, family Orchidaceae; Chase et al. 2015 ) is a clade of seven genera and about 280 species (Salazar et al. 2018 ; POWO 2024 ). This alliance is exclusively Neotropical, widely distributed, and is dominated by its three largest genera: Cyclopogon C.Presl, Pelexia Poit. ex Lindl. and Sarcoglottis C.Presl, which together comprise 85% of its species. A recent phylogeny of subtribe Spiranthinae (Salazar et al. 2018 ) revealed that the Cyclopogon clade is paraphyletic, i.e., it included all species of Cyclopogon sampled but also a nested subclade of Brachystele guayanensis (Lindl.) Schltr. + Veyretia Szlach. (four species sampled). All other species of Brachystele Schltr., including the type, formed a monophyletic separate clade within the Spiranthinae but in another clade called the Pelexia clade by the authors. Brachystele was thus split between the Pelexia clade and the Cyclopogon clade. This scenario suggests the occurrence of parallel evolution of vegetative and floral characters between different lineages of the Spiranthinae that have caused them to be put into the same genus based on morphological characters (e.g., Szlachetko and Rutkowski 2008 ). Brachystele guayanensis has been recently transferred to Cyclopogon (Meneguzzo et al. 2024 ) based on molecular, morphological and the ecological results that are presented here. In 2020 and 2021, the population of Cyclopogon guayanensis from which the sample for the phylogenetic study of the Spiranthinae (Salazar et al. 2018 ) was collected flowered. A second population was also found; both populations were in urban grasslands in Brasilia, Distrito Federal, Brazil. This provided us with an opportunity to study its floral biology, pollinators, micromorphology and histochemistry, unknown until now. A large quantity of data on the floral biology of subtribe Spiranthinae has been amassed by Rodrigo Singer and collaborators (Singer and Cocucci 1999 ; Singer and Sazima 1999 ; Singer 2002 ; Buzatto 2014 ). Also, this data has been recently reviewed and interpreted within a phylogenetic framework (Buzatto et al. 2022 ). The hypothesis for our study was that its floral biology would show: 1) similarities to Cyclopogon due to a shared phylogeny; 2) differences from Cyclopogon , possibly due to parallel evolution with Brachystele sensu stricto . Methods and materials Floral Biology. A flowering population estimated to be of several hundred individuals over an area of c. 0.5 km 2 was found in Brasília (Population A, 15 o 45’ 55” S, 47 o 52’ 47” W) on the 7th November 2020 (Fig. 1 ), followed by a second much smaller population of a few dozen individuals on the 9th of November 2020 (Population B, 15 o 44’ 07” S, 47 o 53’ 24” W)). These two populations were observed between the 8th and 13th November 2020; the first population flowered again in the following year (flowering individuals were first detected on the 21st October 2021) and was observed between 27th October and 9th November 2021. In the Distrito Federal, the day length difference during the flowering period was minimal; sunrise on 20 October was 05:40 and sunset 18:11, and on the 15 November sunrise was 5:30 and sunset 18:22. Observations were made between 6:00–7:00 to 17:00–18:00 (12 hourly intervals) lasting at least 40 min per hour interval, except for intervals 15:00–16:00 (35 min) and interval 17h00–18h00 (25 min), totalling 610 min (just over 10 man hours). Visitor behaviour was observed, including possible resource collection, insect body parts touching fertile organs, and adherence position of the pollinarium. Whenever possible, digital images and videos were recorded, and insects were collected for identification. Collected insects were dried, pinned, labelled, and deposited in the Entomological Collection of the Departamento de Zoologia, Universidade de Brasília, Brazil. They were identified by authors ACA and ACM (see also acknowledgements). A voucher specimen from plant population 1 was collected and is deposited in the UB herbarium ( C.E.B. Proença 5579 ) at the Universidade de Brasília, Brazil, available from the Species Link collection network ( https://specieslink.net/search/ ). Micromorphology and Histochemistry. Five flowering plants were collected and stored in wet paper at 8 o C for c. 48 h. For each plant, two samples were taken from proximal to distal portions of the inflorescence: 1) pre-anthetic buds adjacent to open flowers; 2) open flowers with attached pollinaria; 3) open flowers without pollinaria; 4) old flowers/developing fruits with dry, brown corollas. Four repetitions of these procedures were done, each for a different individual. Samples were immersed in Sudan IV for 15 min, quickly washed in 70% ethanol, immersed in water and photographed using a Zeiss Photomicroscope with an image capture system. Non-treated flowers were also imaged. Since we were unable to detect floral nectar in the field, an inflorescence with buds and open flowers was cut and the stem put in water in the field and taken to the laboratory. After two days, ten freshly opened flowers were removed, dissected, and examined for nectar under a stereomicroscope since corolla tubes were too narrow to allow insertion of microcapillary tubes. As no nectar droplets were detected, the labella were removed and soaked in 5 mL of distilled water, according to the washing method (agitated for 1 min, allowed to soak c. 20 min and frozen) as suggested by Morrant et al. ( 2009 ) as one of the preferrable methods of collecting nectar from flowers with low nectar volume. We were stimulated to try this method, first suggested by Käpylä ( 1978 ), by obvious nectar foraging by floral visitors. The solution was later unfrozen and an aliquot of 100µL was taken (without labella) and then vortexed briefly; this was then centrifuged at 17000 g for 20 min to remove particles and subjected to High Performance Anion Exchange (HPAE) analysis of sugars. Sugars were separated and detected using a Dionex ICS 3000 HPAE equipped with a Carbopac PA10 column and electrochemical detector. The separation was performed using a sodium hydroxide gradient at 0.2 mL.min − 1 exactly as described in Silva et al. ( 2021 ). Sugars were identified and quantified by comparison with a calibration curve constructed using authentic standards. RESULTS Floral biology. The floral scape of Cyclopogon guayanensis is a spike-like raceme c. 15 to 30 cm high. Flowers are resupinate and arranged in a dense ascending spiral, so that the left side of each labellum is adjacent to, and sometimes touches, the lateral sepal of the flower below it (Fig. 2 ). The corolla is creamy-white with the tube externally greenish and internally cream or pale yellow. Flowers are zygomorphic and are c. 3 mm high and 2.5 mm across; the entrance to the tube is c. 1 mm wide; the labellum presents a central, slightly yellowish groove; pollinia are pale yellow and visible; no nectar was observed. The flowers of Cyclopogon guayanensis were visited between 8 AM and 5 PM (Supporting Information, Table S1 ). We observed at least 10 species of insects, mainly bees but also syrphid flies, of which four can be considered pollinators (Fig. 2 , Table 1 ). The pollinators of C. guayanensis are small, generalist bees from non-related groups (two families). Four species of bees from the genera Exomalopsis , Nomada and Tetrapedia (Apidae) and Dialictus (Halictidae) were observed with one or more pollinaria attached to their bodies, reinforcing their role as pollinators (Fig. 2 ); pollinators had in common similar body sizes and tongue lengths. The position and angle of the pollinaria in the images suggest that they are adhered to the ventral surface of the bee labrum (Fig. 2 ) as in Cyclopogon . Unfortunately, captured visitors lacked pollinaria, so we are reluctant to state this unequivocally; it is also possible that they are adhered to the clypeus or proboscis. Several other Halictid bees were also observed visiting and might be pollinators but were captured as they approached or landed on the flowers or lacked pollinaria: Augochlora sp., Augochloropsis sp., and Neocorynura pseudobaccha (Cockerell, 1901). Apparently, all visitors were searching for nectar (Fig. 3 ), collecting it with their tongues. In spite of the visitors’ relatively small sizes, they could not enter the very small flowers of C. guayanensis , so only the head was inserted. Table 1 Floral visitors of Cyclopogon guayanensis populations in the Distrito Federal (Brazil) during the month of November (2020) and October/November (2021). Only days with visits shown (see Table S2 for complete record of observation periods). Date Periods Total time (minutes) and observer Visitors/Pollinators C = captured; O = observed; P = photographed; V = Video recorded. 8 Nov 2020 (Pop 1) (see Fig. 2 ) 07:45–08:05 12:20–12:40 16:40–17:00 20 (CEBP) 20 (CEBP) 20 (CEBP) Apis mellifera Linnaeus, 1758 (O, did not land). Trigona spinipes (Fabricius, 1793) (V). Exomalopsis sp. 1 (C). 9 Nov 2020 population 1 destroyed by urban mowing 11 Nov 2020 (Pop 2) 08:28–09:10 13:58–14:45 42 (CEBP) no visits Bee, unidentified (O); Syrphidae flies (O). 11 Nov 2020 (Pop 2) 11:00–12:00 60 (ACM & AJCA) Exomalopsis sp. 1, female with pollinarium on mouthparts (P). 12 Nov 2020 (Pop 2) 08:30–09:30 13:30–14:30 120 (AJCA) Exomalopsis sp. 1, female (O). Nomada , sp., female with pollinarium on mouthparts (P). Trigona spinipes (O). Exomalopsis sp. 1, female (O). Nanotrigona testaceicornis le Peletier, 1836 (O) Exomalopsis sp. 2, female (O). Dialictus sp., male with pollinarium on mouthparts (P). Tetrapedia sp., male with pollinarium on mouthparts (P). Syrphidae flies (O). 13 Nov 2020 (Pop 2) 13:30–14:30 60 (AJCA) Dialictus sp., female (O). Paratrigona lineata (le Peletier, 1836) (O). Exomalopsis sp. 2, male (O). 21 Oct 2021 2021 flowering population detected. 27 Oct 2021 (Pop 1) 16:40–17:05 25 (CEBP) Dialictus sp. (C). 28 Oct 2021 (Pop 1) 07:45–08:05 20 (CEBP) cf. Trigona (V). 30 Oct 2021 (Pop 1) 10:30–11:00 30 (CEBP) Neocorynura pseudobaccha (Cockerell, 1901), male (P). Augochlora sp., male (C). Hemiptera (O). 01 Nov 2021 (Pop 1) 07:00–07:30 30 (CEBP) Augochloropsis sp. (P). 02 Nov 2021 (Pop 1) 12:30–12:40 10 (CEBP) Dialictus sp., male (C). 09 Nov 2021 (Pop 1) 6:50–7:00 10 (CEBP) Augochloropsis sp. (P) sleeping. Micromorphology and Histochemistry. The micromorphological analysis as well as the histochemical results of the Sudam IV test are presented in Fig. 4 . Tector trichomes were not observed on the inflorescence. Two types of glandular trichomes were present, one pedunculate with a secretory head, and the other of the papillae type. The bracteoles are ciliate with 4–8–celled glandular trichomes (Fig. 4 F–G). The sepals present (2–3)4(–5)–celled glandular trichomes on the abaxial (external) surface that are dense along the midveins but thin out towards the distal regions. Lipid secretion from the glandular trichomes is insignificant in pre-anthetic buds (Fig. 4 A, J), but intense in open (perhaps male-phase?) flowers with the pollinarium still attached (Fig. 4 B, L), as well as in the flowers in which the pollinarium is absent (Fig. 4 C) and in the senescent flowers (Fig. 4 D), i.e., the trichomes persist and do not fall off or dry out, at least in the senescent flowers immediately below the open flowers. The petals are covered with one-celled papillae on the inner surface; these papillae are mostly short (c. 1.5 times as long as wide) except on the labellum on which the papillae are longer, c. 2–3 times as long as wide (Fig. 4 M–N). In both types of papillae, periplasmic spaces were observed to form within the cells, but these are much more developed in the long than in the short papillae. The contents of these periplasmic papilla spaces did not stain with Sudan IV (Fig. 4 N, arrow). Sepals and petals form a short floral tube (Fig. 4 H) and have many scattered idioblasts with raphids (Fig. 4 H, head-arrow, I), as do the bracteoles (Fig. 4 F–G, head-arrow). The pollen within the squashed pollinaria is shed in tetrads (Fig. 4OP) and the ovule is unitegmic (Fig. 4 Q). Nectar composition. The sugar composition from HPAE analysis of the solution obtained from the 10 labella was: 5.5% sucrose, 53.8% glucose, and 40.7% fructose by mass. No other monosaccharides or oligosaccharides were detected. A total of 94.5% of the sugar in the sample was therefore hexose. DISCUSSION The floral biology of the Spiranthinae was stated to be “much more complex than cursory comparisons suggest” (Salazar et al. 2018 : 277). A recent review of the floral biology of Pelexia clade (Buzatto et al. 2022 ) states that orchids in this clade are pollinated mainly by bees, especially those from the family Halictidae, which are attracted by the nectar produced as a reward (Table 2 ). The flowers are, in general, small for the family, white, with floral parts covered with carpets of glandular hairs. Cyclopogon guayanensis conforms very well to this pattern but stands out due to the wide taxonomic diversity of both pollinators and visitors, and lack of visible nectar. Bee visitation observed in Cyclopogon guayanensis closely follows the description given by Singer and Cocucci ( 1999 ) for C. diversifolius (Cogn.) Schltr., with pollinia possibly adhering to the underside of the bee labrum. These authors hypothesized that C. diversifolius , as well as the other two non-related species they studied [ Campylocentrum aromaticum Barb.Rodr. and Prescottia densiflora (Brong.) Lindl.] are pollinated mainly by Halictid bees and well-adapted for “the particular swivel proboscis mechanism of the halictid bees for pollinaria removal and deposition” (Singer and Coccuci 1999: 112). In C. guayanensis , although halictid bees were present, their role as pollinators was overshadowed by the Apidae, i.e. Exomalopsis , Tetrapedia and Nomada (observed bearing pollinaria) and by stingless bees as visitors. This did not seem to be associated to any significant differences in bee body size, pollinaria attachment, or behaviour. We suggest this could be, at least in part, a product of the different bee fauna in our study area. Halictidae are highly abundant, surpassing the Apidae in several surveys (Martins et al. 2013) in subtropical and temperate regions of South America (where other studies of Cyclopogon pollinators have been done; e.g., Singer and Coccuci 1999; Singer and Sazima 1999 ; Galetto et al. 1997 ;Benitez-Vieyra et al. 2006 ). Buzatto et al. ( 2022 ) noted changes in the adherence position of pollinaria on the bee labrum in the phylogenetic tree of species in the Pelexia clade using ancestral character state reconstruction. These authors hypothesized that the ancestor of the Pelexia alliance had ventrally viscous pollinia and noted that the two most basal species Coccineorchis cernua (Lindl.) Garay and Sauroglossum elatum Lindl. (respectively pollinated by hummingbirds and lepidopterans) retained this ancestral character. The shift to hymenopteran pollination was accompanied by a shift from ventral to dorsal pollinia that adhere to the ventral surface of the bee labrum in Cyclopogon comosus (Rchb.f.) Burns-Bal. & E.W.Greenw., Pachygenium bonariensis (Lindl.) Schltr., Pelexia adnata (Sw.) Poit. ex Rich., Sarcoglottis acaulis (Sm.) Schltr., and with a reversal to ancestral ventral pollinia in Brachystele unilateralis (the type species of the genus), i.e., a member of Brachystele sensu stricto . Thus, if adherence of pollinia to the inner surface of the bee labrum in C. guayanensis is confirmed in future captured bees, its transfer to Cyclopogon first suggested by molecular markers (Salazar et al. 2018 ) will be further strengthened and will also sustain the evolutionary scenario proposed by Buzatto et al. ( 2022 ) for this character. When commenting on the position of Cyclopogon guayanensis in the Spiranthinae phylogenetic tree, Salazar et al. ( 2018 : 296) noted the difference in flower size between the C. guayanensis (then Brachystele guayanensis ) and Veyretia spp. and stated that: “upon close examination, it is evident that its flowers have the two-chambered nectary of Veyretia (although more shallowly so in C. guayanensis , in proportion to its noticeable reduction in flower size). This shallow two-chambered nectary was not seen. Abundant nectar is reported for some Cyclopogon species (Singer and Cocucci 1999 ; Wiemer et al. 2009 ), but this was not the case of C. guayanensis , in which neither the capillary tube and nor paper filter methodologies were capable of collecting nectar. Nectar is secreted by the papillae on the inner surface of the labellum, particularly along its central groove, in minute quantities. Similar papillae have been detected in C. apricus (Adachi 2015 ) and C. dutrae (Galetto et al. 1997 ). Nectar secreting papillae on the inner surface of the labellum have also been found in the ghost orchid, Epipogium aphyllum Sw., subtribe Epipogiinae, tribe Gastrodieae, subfamily Epidendroideae, by Swięczkowska and Kowalkowska ( 2015 ), a northern temperate mycotrophic orchid pollinated by Bombus bees. Nectar is secreted along the central groove of the labellum of another mycotrophic orchid, European Epipactis atropurpurea Raf. (Pais and Figueiredo 1994 ), tribe Neottiae, subfamily Epidendroideae (Chase et al. 2015 ), which has, however, epidermal nectariferous tissue along the groove and not papillae. Nectariferous tissue is composed of epidermal, specialized parenchymatic cells present on the surfaces of plant tissue that are usually either elevated or sunken (Fahn 1988 ; Galetto et al. 1997 ). In many orchids, the nectariferous tissue contains starch grains in the pre-secretory stage, which is the energy source to produce the nectar (Pais and Figueiredo 1994 ; Stpiczyńska and Matusiewicz 2001 ). Starch grains are frequent in angiosperm nectaries, and vascular bundles also can occur, although not necessarily (Fahn 1988 , 1989 ). Nectar-secreting papillae (secreting minute quantities of nectar) have also recorded the Dactylorhiza maculata complex, tribe Orchidieae, subfamily Orchidoideae, but these are in the spur (Naczk et al. 2018 ) not on the labellum. Papillae secreting “floral rewards” (a mixture of carbohydrates, lipids and proteins that feed its midge pollinators - Ceratopogonidae, Diptera) have also been recorded on the labellum of the neotropical genus Trichosalpinx Luer, subtribe Pleurothallidinae, tribe Epidendreae, subfamily Epidendroideae (Bogarín et al. 2018 ). Thus, the exact combination of nectariferous papillae on the inner surface of a labellum that does not form a spur (Fig. 4 M-N, arrows), associated to the confirmed presence of nectar sugars is, as far as we are aware, a novelty in subfamily Orchidoideae. Papillae conclusively shown to produce nectar have been recorded in the Orchidoideae, but these are all within spurs, i.e., in several genera of subfamily Orchidoideae, subtribe Orchidinae (Bell et al. 2009 ). In spurless Cyclopogon apricus , similar papillae have been detected and these were interpreted as nectaries (Adachi 2015 ). Field studies on the reproductive biology of C. apricus have been done and have shown that it secretes an exsudate considered by the authors to be nectar (Sazima and Cocucci 1999). We consider it highly likely that the secretion produced by C. apricus is nectar, and that its papillae are analogous to the nectariferous papillae of C. guayanensis. The early literature stated that floral nectar is mostly composed of varying proportions of sucrose, glucose and fructose (Percival 1961 ; Baker and Baker 1983 ). This composition has been widely supported by later research (Chalcoff et al. 2017 ), although other components, such as amino acids, can also be important in the plant-pollinator interaction (Gottsberger et al. 1984 ; Petanidou et al. 2006 ; Brzosko and Mirski 2021 ). Baker and Baker ( 1983 ) proposed a classification of floral nectar into four types based on an “r” ratio of sucrose/fructose + glucose: 1) sucrose dominant (r > 0.99); 2) sucrose rich (r = 0.5–0.99); 3) hexose rich (r = 0.1–0.5); 4) hexose dominant (r < 0.1). Floral nectar sugar composition (and its associated ecological drivers) were recently reviewed for the angiosperms by Chalcoff et al. ( 2017 ) and for the Orchidaceae by Brzosko and Mirski ( 2021 ). The nectar of Cyclopogon guayanensis is the second record of a hexose-dominant nectar (type 4 in the system of Baker and Baker 1983 ) in the Orchidaceae. The first published record of a hexose dominant nectar in the Orchidaceae is very recent, of Prasophyllum innubum D.L. Jones (Hayashi et al. 2024). P. innubum shows remarkable similarities to C. guayanense (Table 3 ). A taxonomically updated list of nectar types in the Orchidaceae, mostly based on Chalcoff et al. ( 2017 ) and Brzosko and Mirski ( 2021 ) with some additional records, is presented in Table 2 . Table 2 Orchidaceae with known nectar composition and their pollinator groups ordered by subfamily and tribe. Nectar composition in average values when more than one individual or flower was sampled per taxon. EP = subfamily Epidendroideae; OR = subfamily Orchidoideae; VA = subfamily Vanilloideae; Coll = tribe Collabieae; Cran = tribe Cranichideae; Cymb = tribe Cymbidieae; Dend = tribe Dendrobieae; Diur = tribe Diurideae; Neot = tribe Neottieae; Orch = tribe Orchideae; Vand = tribe Vandeae; Vani = tribe Vanilleae. * name updated to follow Plants of the World Online (https://powo.science.kew.org ); r = sucrose/(fructose + glucose); nectar class follows Baker & Baker (1983). Adapted from Brzosko & Mirsky (2021) and Chalcoff et al. (2017) with additions. Higher taxa Species, r value and nectar class Visitors References EP, Coll Calanthe angustifolia (Blume) Lindl. r = 3.27 = sucrose dominant Unknown Freeman et al. (1991) EP, Cymb Eulophia alta (L.) Fawc. & Rendle r = 0.8 = sucrose rich Hymenoptera (Bees) Jürgens et al. (2009) EP, Cymb Eulophia cochlearis Lindl. * r = 2.33 = sucrose dominant Hymenoptera (Bees) Peter & Johnson (2009) EP, Cymb Maxillaria anceps Ames & C.Schweinf. r = 70.86 = sucrose dominant Hymenoptera (Bees) Davies et al. (2005) EP, Cymb Ornithidium fulgens ((Rchb.f.) L.O.Williams r = 13.7 = sucrose dominant Hummingbirds Lipińska et al. (2022) EP, Dend Dendrobium spp (34 species from SE Asia) sucrose dominant Hymenoptera (Bees) Jia & Huang (2022) EP, Neot Epipactis helleborine (L.) Crantz r (natural areas) = 1.5–2.5 = sucrose dominant r (disturbed areas) = 0.7 = sucrose rich Hymenoptera (mainly) Brzosko et al. (2023) EP, Neot Epipactis atrorubens (Hoffm.) Besser * r = 0.27 = hexose rich Insects (several orders) Pais & Neves (1980) EP, Neot Neottia ovata (L.) Hartm. r = 0.14–0.3 = hexose rich Insects (several orders) Brzosko et al. (2021) EP, Vand Cleisostoma lecongkietii Tich & Aver. * r = 20.89 = sucrose dominant Hymenoptera (Bees) Ponert et al. (2016) EP, Vand Rhipidoglossum caffrum (Bolus) Farminhão & Stévart * r = 4.26 = sucrose dominant Lepidoptera (Moths) Luyt (2002) OR, Cran Cyclopogon dutrae Schltr. r = 8.17 = sucrose dominant Hymenoptera (Halictidae) Galetto et al. (1997) O, Cran Cyclopogon guayanensis (Lindl.) B.M. Carvalho & Meneguzzo r = 0.06 = hexose dominant Hymenoptera, Diptera (Apidae, Halictidae) (Syrphidae) This study OR, Cran Goodyera repens (L.) R.Br. r = 0.18–0.44 = hexose rich Hymenoptera ( Bombus ) Brzosko et al. (2023) OR, Cran Sacoila lanceolata (Aubl.) Garay r = 0.50 = hexose rich Trochilidae (Hummingbirds) Galetto et al. (1997) OR, Diur. Caladenia arenaria Fitzg. r = 19.0 = sucrose dominant Hymenoptera (Wasps) Reiter et al. (2019) OR, Diur. Caladenia colorata D.L.Jones r = 19.0 = sucrose dominant Hymenoptera (Wasps) Reiter et al. (2019) OR, Diur. Caladenia nobilis Hopper & A.P.Br. r = 1.0 = sucrose dominant Hymenoptera (Wasps) Phillips et al. (2020) OR, Diur. Caladenia paludosa Hopper & A.P.Br. r = 2.37 = sucrose dominant Hymenoptera (Wasps) Phillips et al. (2020) OR, Diur Caladenia robinsonii G.W.Carr. r = 58.5 = sucrose dominant Hymenoptera (Wasps) Phillips et al. (2024) OR, Diur. Caladenia versicolor G.W.Carr r = 19.0 = sucrose dominant Hymenoptera (Wasps) Reiter et al. (2019) OR, Diur. Caladenia xanthochila D.Beards. & C.Beards. r = 100 = sucrose pure Hymenoptera (Wasps) Reiter et al. (2023) OR, Diur. Prasophyllum innubum D.L.Jones r = 0.01 = hexose dominant Insects (several orders) Hayashi et al. (2024) OR, Orch Bonatea cassidea Sond. r = 67.5 = sucrose dominant Lepidoptera (Butterflies) Balducci et al. (2019) OR, Orch Bonatea polypodantha (Rchb.f.) L.Bolus r = 4.34 = sucrose dominant Lepidoptera (Moths) Balducci et al. (2020) OR, Orch Dactylorhiza incarnata (L.) Soó r = 2.63 = sucrose dominant Hymenoptera Naczk et al. (2018) OR, Orch Dactylorhiza maculata var. fuchsii (Druce) Hyl. r = 5.06 = sucrose dominant Coleoptera, Diptera Gutowski (1990); Naczk et al. (2018) OR, Orch Dactylorhiza maculata (L.) Soó var. maculata r = 4.82 = sucrose dominant Hymenoptera Naczk et al. (2018); Koivisto, Valius & Salonen (2002) OR, Orch Dactylorhiza majalis (Rchb.) P.F.Hunt & Summerh. r = 3.63 = sucrose dominant Diptera, Coleoptera Hymenoptera Naczk et al. (2018) OR, Orch Disa cooperi Rchb.f. r = 0.89 = sucrose rich Lepidoptera (Moths) Johnson (1995); Johnson (2006) OR, Orch Elleanthus brasiliensis (Lindl.) Rchb.f. r = 27.99 = sucrose dominant Trochilidae (Hummingbirds) Nunes et al. (2013) OR, Orch Gymnadenia conopsea (L.) R.Br. r = 4.2 = sucrose dominant Lepidoptera (Butterflies) Gijbels et al. (2014) OR, Orch Habenaria hieronymi Kraenzl. r = 0.19 = hexose rich Hymenoptera Galetto et al. (1997) OR, Orch Habenaria gourlieana Gillies ex Lindl. r = 5.9–22.26 = sucrose dominant Lepidoptera (Hawkmoths) Galetto et al. (1997) OR, Orch Habenaria obtusa Lindl. * r = 27.5 = sucrose dominant Lepidoptera Gottsberger et al. (1984) OR, Orch Pelexia bonariensis (Lindl.) Schltr. r = 1.70 = sucrose dominant Hymenoptera ( Bombus ) Galetto et al. (1997); Buzatto et al. (2022) VA, Vani Vanilla hartii Rolfe r = 5.64 = sucrose dominant Hymenoptera ( Euglossa ) Watteyn et al. (2023) Table 3 Comparative characteristics of the only two species of orchids known to produce hexose-rich nectar Functional trait P. innubum C. guayanense Comparison Geographic distribution Narrow endemic Widespread different Habit Geophyte Geophyte equal Habitat Grasslands and peatlands by streams Highland grasslands, savannas and pastures similar Flowering populations Dense Dense similar Flowering plant size 30-90cm 9-40cm overlapping Flowers per spike 6–20 flowers (9–)30–120(–160) overlapping Flower colour Petals white or purplish Labellum white or pink Petals creamy white Labellum yellowish cream similar similar Flower size 6-9mm across; Labellum 7–9 x 3-3.5mm 4–6 across; Labellum 3.5–4.3 x 1.8-2.8mm overlapping different Flower resupination Not resupinate Resupinate different Visitors observed with pollinaria Bees: Apidae, Halictidae, Wasps (1 species) Bees: Apidae, Halictidae similar Hexose-dominant nectar is rare in orchids (Table 2 ), but is the same true outside of the orchids? To address this question, we segregated all the species with hexose-dominant nectars (but at least 1% sucrose) that were herbs, shrubs or subshrubs, and pollinated by either bees or generalists from the list of 1214 angiosperm with data on nectar sugars compiled by Chalcoff et al. ( 2017 ). This segregate list recorded 45 species in ten botanical families that were widely scattered across the angiosperm phylogenetic tree. We then investigated these 45 species in Plants of the World (POWO 2024 ) and reliable identifications in the I-naturalist site and found that they followed a loose pattern (with some exceptions). White, cream, yellow or orange were the common colours, while pink, violet or purple were rare, and red was absent. Most of them had small, densely aggregated flowers, but there were some exceptions to this norm (e.g., Tecoma stans (L.) Juss. ex Kunth). Virtually all were temperate or subtropical plants, although the plants listed by Chalcoff et al. ( 2017 ) were mostly tropical. In a semi-desertic, frost-prone scrubland in Patagonia, presumably pollinator hostile, most plants had hexose-dominant nectars and were bee-pollinated (Bernardello et al. 1999 ). We propose the term ‘modest’ pollination syndrome be applied to orchids that are: geophytic, have small, pale flowers (probably below 1 cm), offer imperceptible quantities of hexose-dominant nectar on an exposed labellum and attract a wide range of insect visitors. Considering the high species richness of the Orchidaceae, nectar records are surprisingly few (Brzosko et al. 2021 ). Sucrose-dominant nectar predominates both in the angiosperms (56.8% of 1214 species; Chalcoff et al. 2017 ) and in the Orchidaceae (80.5% of 43 species; Brzosko and Mirski 2021 ). Pollinator group was statistically confirmed in both studies as the main ecological driver, followed by climate, i.e., latitudinal climatic zone (for the angiosperms) or climate type (for the orchids). Baker and Baker ( 1983 ), studying nectar composition in 765 species of angiosperms, found that 44% of species pollinated by short-tongued bees produced hexose-dominant nectar, while only 6% of species pollinated by long-tongued bees had this type of nectar. Wilmer ( 2011 ) has argued that sucrose/hexose ratios may have more to do with maintaining optimum nectar concentration and viscosity than pollinator preference. Pure sucrose nectar dries out faster than pure hexose nectar at the same humidity levels (Corbet et al. 1979 ). Therefore, hexose-rich nectar might be preferentially produced by exposed nectaries (pollinated by short-tongued insects), and sucrose-rich nectar by deep, hidden nectaries (pollinated by long-tongued insects). However, Brzosko and Mirski ( 2021 ) found no statistical differences of sugar composition between orchids that offer spur nectar and open nectar, although these authors noted that generalist species were under-represented in the available data. It is possible that when nectar is produced not only by exposed nectaries, but in minute quantities in plants that form dense populations (such as was recorded in Cyclopogon guayanensis and Prasophyllum innubum ), natural selection will favour high-hexose nectar that is more resistant to desiccation. It is worth mentioning in this context that C. guayanensis flowers in early wet season when mean daily humidity is very high and is also a generalistic species, with a wider taxonomic range of bee pollinators than any other species in either the Pelexia or the Cyclopogon clades sensu Salazar et al. ( 2018 ) with known pollinators (Supporting information, Table S2). The glandular trichomes that abound on Cyclopogon guayanensis inflorescences and outer surfaces of the flowers are lipid secreting (Fig. 4 L); these lipids may be acting as aromatic attractants as recorded in C. elatus (Sw.) Schltr., by Wiemer et al. ( 2009 ) or as rewards for oil-collecting or scent-collecting bees. Pachygonium pteryganthum (Rchb. f. & Warm.) Schltr., a member of the Pelexia clade, is pollinated by oil-collecting female Centris ( Melacentris ) bees (Buzatto et al. 2022 ). In our study area, male Tetrapedia bees are known to collect oil from Malpighiaceae flowers (Cappellari et al. 2012 ) and we observed a male Tetrapedia bee visiting the flowers of C. guayanensis , but no such oil-collecting activity was observed. The Tetrapedia bee was foraging for nectar, and is presumed to be a pollinator, as it gathered three pollinaria during visits, which it subsequently tried to remove with front legs. Volatile chemicals (scent) can also be collected for mating purposes by male Neotropical orchid bees, i.e. Euglossini (Carvalho-Filho 2010). Despite the high density of glandular trichomes on the C. guayanensis inflorescences, there was no evidence of this kind of reward collecting by pollinators in our study; Euglossini visitors were not observed in the field and glandular trichomes were intact, not destroyed by visitors, with the cuticle on the heads undamaged (Fig. 4 G, J–L). A sweet scent was reported in the flowers of Cyclopogon congestus (Vell.) Hoehne (Singer and Sazima 1999 ), C. diversifoIius (Cogn.) Schltr. (= C. apricus (Lindl.) Schltr.) (Singer and Cocucci 1999 ), C. elatus (Wiemer et al. 2009 ) and Veyretia hassleri (Cogn.) Szlach. (Supporting Information, Table S2). In C. congestus , however, the scent, which was perceived from the morning to the evening hours, was produced by apical callosities on the inner surface of the labellum and lateral sepals (Singer and Sazima 1999 ), and is thus not analogous to the multicellular, glandular trichomes observed on the outer surface of the corolla in C. guayanensis. In Cyclopogon elatus , osmophores are reported as trichomes on the outer surface of the labellum (Wiemer et al. 2009 ) such as was recorded by us in C. guayanensis . However, in C. elatus these trichomes are unicellular, while in C. guayanensis they are pluricellular, with stalk and head, but also occur on the outer surface of the labellum (as well as on other inflorescence surfaces). Also, in C. elatus , only the osmophores of open flowers release scent, which is absent in buds and withered flowers (Wiemer et al. 2009 ). Thus, C. guayanensis also differs from C. elatus in this aspect, since secretion appears to persist in senescent flowers (Fig. 4 D). The combined evidence suggests that the glandular trichomes on the inflorescence and outer surface of the flowers of Cyclopogon guayanensis are probably osmophores. However, the scent detected in C. guayanensis was extremely faint and was in fact only perceived by one of us; therefore, the function and composition of the lipids secreted by these trichomes should be the subject of further investigation. The external position on the flower is unusual for osmophores; the inner surface of the labellum is the most widespread scent-releasing surface in orchids (Wiemer et al. 2009 ). In fact, very few angiosperms have osmophores on the outer surface of the flowers, as seems to be the case in Cyclopogon ; it was also reported in Cotylolabium lutzii (Pabst) Garay, another genus of the Spiranthinae that is sister taxon to the rest of the Subtribe (Borba et al. 2014 ). Perhaps the presence of osmophores on the outer surface of the flowers is a common characteristic of this subtribe; this hypothesis would require further investigation. The cuticle allows both scent diffusion in osmophores and secretion releasing in nectaries; the cuticle expands and there is secretion accumulation in the periplasmic space; this phase was clearly recorded in the nectariferous papillae of Cyclopogon guayanensis in our study (Fig. 4 M–N, arrows). In the secretory labellum tissue of Epipactis atropurpurea , the nectar is released by disruption of the epidermal cell cuticle in the secretory stage (Pais and Figueiredo 1994 ). In the nectariferous papillae of cotton ( Gossypium hirsutum L., Malvaceae), however, a two-layered cuticle is detached from the wall in the secretory papillae and the nectar crosses this structure (Eleftheriou and Hall 1983 ); further studies are needed to clarify the nectar releasing mechanism in C. guayanensis . Raphid-rich idioblasts have been presumed to be herbivore deterrents (Molano-Flores 2001 ). Raphid containing idioblasts are not widespread in dicotyledons (Cutler et al. 2008 ) but are found in many monocotyledons (Fahn 1988 ) and were observed in the bracteoles (Fig. 4 F–G), sepals and petals (Fig. 4 H) of Cyclopogon guayanensis . Raphid-rich idioblasts occur in several species of orchids, both in subfamilies Orchidoideae and Epidendroideae. In the Orchidoideae, they are found in the floral parts of Habenaria gourlieana Gillies ex Lindl. (Galetto et al. 1997 ), and in the hypochilum of Cotylolabium lutzii (Borba et al. 2014 ) – also a member of subtribe Spiranthinae and were noted to be common in this subtribe by Adachi ( 2015 ), based on studies of floral anatomy of Cyclopogon apricus , Mesadenella cuspidata (Lindl.) Garay, Sarcoglottis fasciculata , and Sauroglossum elatum. In subfamily Epidendroideade, they occur in the ghost orchid, Epipogium aphyllum (Swięczkowska and Kowalkowska 2015 ). However, the density of idioblasts is noticeably higher in the sepals and petals of C. guayanensis (Fig. 4 H, arrowheads) than in most of these orchids. In many orchids of the subtribe Pleurothallidinae, prismatic crystals occur as idioblasts in the floral parts and have been associated to visual attraction of pollinators (Bogarín et al. 2018 ), but herbivore dissuasion is another possible role. The fact that herbaceous or shrubby plants with hexose-dominant nectar and generalistic pollination systems are usually confined to temperate or subtropical environments (Chalcoff et al. 2017 ) but appeared in a tropical savanna grassland species is interesting. In the highly seasonal Cerrado biome where our study was carried out, 90% of annual precipitation occurs between the months of October and April, followed by a dry season lasting between 4 and 7 months (Bustamente et al. 2012); in the Distrito Federal, c. 50% of annual precipitation occurs between December and February (Anunciação et al. 2014 ). We tentatively suggest that a short favourable reproductive season is the driver behind this suite of characters. Its similarity to Epipogium aphyllum suggests convergence with these orchids (Swiwczkowska and Kowalkowska 2015). Our theory for the unusual characteristics of C. guayanensis is that, as a therophytic orchid that inhabits fire-prone, highly seasonal savanna grasslands, it will presumably be under two selective forces: 1) lack of competition, since grasslands are potentially resource-poor landscapes for pollinating insects and will tend to have low pollinator density, therefore favouring a “take what you can get” generalist pollination strategy offering scanty rewards; 2) a limited growing and flowering season (during the short wet season) which would put a premium on economy of energy, i.e., favour small plants with small flowers, small fruits, and minimalistic pollinator rewards. The floral biology (position of the viscidium and pollinator behaviour) and micromorphological data gathered in this study (external glandular hairs, raphid-rich idioblasts, internal nectariferous papillae) support the transfer of Brachystele guayanensis to Cyclopogon (Meneguzzo et al. 2024 ). Our hypothesis is that the C. guayanensis – Veyretia clade is a lineage within Cyclopogon (a predominantly forest genus well adapted to pollination by halictid bees) that has moved into open habitats with accompanying pollinator shifts (i.e., from Halictidae to Apidae and possibly from Halictidae to Megachilidae, respectively; see Table S2), although this would need further investigation of the floral biology of Veyretia . Studies of species of Brachystele s.s. would obviously also be desirable to confirm parallel evolution. To conclude, on a more general note, we would suggest further testing for trace nectar in orchids that apparently offer no rewards. We cite verbatim a paragraph from the study by Shrestha et al. ( 2020 : 5) on rewardlessness in orchids that reflects our beliefs: If neural mechanisms of reward detection can be exploited and are widespread among floral visitors, the use of such stingy rewards by orchids lacking visible nectar might also be widespread. Pollinator manipulation by trace rewards might still be considered largely deceitful, but the nature of the deceit would be more complex and more subtle than in the case of complete absence of floral sugars. A paucity of reward may actually encourage appropriate flower-handling by visitors. Declarations ACKNOWLEDGEMENTS We thank Prof. Rodrigo Barbosa Gonçalves (Universidade Federal do Paraná) for identifying or confirming the identification of several of the bees. Funding FAPERJ ( Fundação de Amparo à Pesquisa do Rio de Janeiro ) funded a post-doctoral grant and financial support (grants n. E-26/206.092/2022 and E-26/206.093/2022) to TECM. CNPq ( Conselho Nacional de Desenvolvimento Científico e Tecnológico , Brazil) funded PQ2 Produtividade em Pesquisa research grants to CEBP and JANB. Competing interests The authors declare no competing interests. Author contributions TECM and CEBP conceived the project and designed the experiments. CEBP, AJCA and ACM did the field work, produced images and videos, and incorporated voucher specimens of plants and insects into scientific collections. ACM and AJCA identified the insects. SMG did the anatomical and histochemical analysis. TCRW analyzed the nectar sugars. CEBP wrote the manuscript with significant contributions from TECM, JANB, and SMG. All authors contributed to revisions and accepted the final version of this manuscript. Supporting information Additional supporting information may be found online in the Supporting Information section at the end of the article. Tables S1 and S2. References Adachi SA (2015) Estrutura floral de representantes da tribo Cranichideae (Orchidoideae: Orchidaceae). Universidade Estadual Paulista “Júlio de Mesquita Filho” Anunciação YMT da, Walde DHG, Rocha RP da (2014) Observed summer weather regimes and associated extreme precipitation over Distrito Federal, west-central Brazil. Environ Earth Sci 72:4835–4848. https://doi.org/10.1007/s12665-014-3607-9 Baker HG, Baker I (1983) Floral nectar sugars constituents in relation to pollinator type. In: Jones CE, Little RJ (eds) Handbook of experimental pollination biology. Van Nostrand Reinhold, New York, pp 117–141 Balducci MG, van der Niet T, Johnson SD (2019) Butterfly pollination of Bonatea cassidea (Orchidaceae): Solving a puzzle from the Darwin era. South African J Bot 123:308–316. https://doi.org/10.1016/j.sajb.2019.03.030 Balducci MG, Van Der Niet T, Johnson SD (2020) Diel scent and nectar rhythms of an African orchid in relation to bimodal activity patterns of hawkmoth pollinators. Ann Bot 126:1155–1164. https://doi.org/10.1093/aob/mcaa132 Bell AK, Roberts DL, Hawkins JA, et al (2009) Comparative micromorphology of nectariferous and nectarless labellar spurs in selected clades of subtribe Orchidinae (Orchidaceae). Bot J Linn Soc 160:369–387. https://doi.org/10.1111/j.1095-8339.2009.00985.x Benitez-Vieyra S, Medina AM, Glinos E, Cocucci AA (2006) Pollinator-mediated selection on floral traits and size of floral display in Cyclopogon elatus , a sweat bee-pollinated orchid. Funct Ecol 20:948–957. https://doi.org/10.1111/j.1365-2435.2006.01179.x Bernardello G, Galetto L, Forcone A (1999) Floral nectar chemical composition of some species from Patagonia. II. Biochem Syst Ecol 27:779–790. https://doi.org/10.1016/S0305-1978(99)00029-0 Bogarín D, Fernández M, Borkent A, et al (2018) Pollination of Trichosalpinx (Orchidaceae: Pleurothallidinae) by biting midges (Diptera: Ceratopogonidae). Bot J Linn Soc 186:510–543. https://doi.org/10.1093/botlinnean/box087 Borba EL, Salazar GA, Mazzoni-Viveiros S, Batista JAN (2014) Phylogenetic position and floral morphology of the Brazilian endemic, monospecific genus Cotylolabium : A sister group for the remaining Spiranthinae (Orchidaceae). Bot J Linn Soc 175:29–46. https://doi.org/10.1111/boj.12136 Brzosko E, Bajguz A, Burzyńska J, Chmur M (2023) Does Reproductive Success in Natural and Anthropogenic Populations of Generalist Epipactis helleborine Depend on Flower Morphology and Nectar Composition? Int J Mol Sci 24:4276. https://doi.org/10.3390/ijms24054276 Brzosko E, Bajguz A, Chmur M, et al (2021) How are the flower structure and nectar composition of the generalistic orchid Neottia ovata adapted to a wide range of pollinators? Int J Mol Sci 22:1–27. https://doi.org/10.3390/ijms22042214 Brzosko E, Mirski P (2021) Floral nectar chemistry in orchids: A short review and meta-analysis. Plants 10:2315. https://doi.org/10.3390/plants10112315 Bustamante MMC, Nardoto GB, Pinto AS, et al (2012) Potential impacts of climate change on biogeochemical functioning of Cerrado ecosystems. Brazilian J Biol 72:655–671 Buzatto CR (2014) Estudos taxonômicos, filogenéticos e biossistemáticos em orquídeas terrestres (Orchidaceae: Orchidoideae) brasileiras. Universidade Federal do Rio Grande Sul Buzatto CR, Nervo MH, Sanguinetti A, et al (2022) Efficient pollination and high reproductive success in two Brazilian Spiranthinae orchids: Insights on the evolutionary history of pollination within the Pelexia clade. Plant Species Biol 37:182–196. https://doi.org/10.1111/1442-1984.12366 Cappellari SC, Melo GAR, Aguiar AJC, Neff JL (2012) Floral oil collection by male Tetrapedia bees (Hymenoptera: Apidae: Tetrapediini. Apidologie 43:39–50. https://doi.org/10.1007/s13592-011-0072-2 Carvalho Filho F da S (2010) Scent-robbing and fighting among male orchid bees, Eulaema ( Apeulaema ) nigrita Lepeletier, 1841 (Hymenoptera: Apidae: Euglossini). Biota Neotrop 10:405–408. https://doi.org/10.1590/s1676-06032010000200038 Chalcoff VR, Gleiser G, Ezcurra C, Aizen MA (2017) Pollinator type and secondarily climate are related to nectar sugar composition across the angiosperms. Evol Ecol 31:585–602. https://doi.org/10.1007/s10682-017-9887-2 Chase MW, Cameron KM, Freudenstein J V., et al (2015) An updated classification of Orchidaceae. Bot J Linn Soc 177:151–174. https://doi.org/10.1111/boj.12234 Corbet SA, Unwin DM, Prys‐Jones OE (1979) Humidity, nectar and insect visits to flowers, with special reference to Crataegus , Tilia and Echium . Ecol Entomol 4:9–22. https://doi.org/10.1111/j.1365-2311.1979.tb00557.x Cutler DF, Botha T, Stevenson DW (2008) Plant anatomy: An applied approach. Blackwell Publishing Ltd, Malden, Massachusetts, USA Davies KL, Stpiczyńska M, Gregg A (2005) Nectar-secreting floral stomata in Maxillaria anceps Ames & C. Schweinf. (Orchidaceae). Ann Bot 96:217–227. https://doi.org/10.1093/aob/mci182 Eleftheriou EP, Hall JL (1983) The extrafloral nectaries of cotton: I. Fine structure of the secretory papillae. J Exp Bot 34:103–119. https://doi.org/10.1093/jxb/34.2.103 Fahn A (1989) Plant anatomy. Pergamon Press, Oxford Fahn A (1988) Secretory tissues in vascular plants. New Phytol 108:229–257. https://doi.org/10.1111/j.1469-8137.1988.tb04159.x Forcone A, Galetto L, Bernardello L (1997) Floral nectar chemical composition of some species from Patagonia. Biochem Syst Ecol 25:395–402. https://doi.org/10.1016/S0305-1978(97)00030-6 Freeman CE, Worthington RD, Jackson MS (1991) Floral Nectar Sugar Compositions of Some South and Southeast Asian Species. Biotropica 23:568. https://doi.org/10.2307/2388394 Galetto L (1995) Estructura del nectario y composición posición química del néctar en cuatro especies de Scrophulariaceae. Kurtziana 24:105–118 Galetto L, Bernardello G (2003) Nectar sugar composition in angiosperms from Chaco and Patagonia (Argentina): An animal visitor’s matter? Plant Syst Evol 238:69–86. https://doi.org/10.1007/s00606-002-0269-y Galetto L, Bernardello G, Rivera GL (1997) Nectar, nectaries, flower visitors, and breeding system in five terrestrial Orchidaceae from central Argentina. J Plant Res 110:393–403. https://doi.org/10.1007/bf02506798 Gijbels P, Van den Ende W, Honnay O (2014) Landscape scale variation in nectar amino acid and sugar composition in a Lepidoptera pollinated orchid species and its relation with fruit set. J Ecol 102:136–144. https://doi.org/10.1111/1365-2745.12183 Gottsberger G, Schrauwen J, Linskens HF (1984) Amino acids and sugars in nectar, and their putative evolutionary significance. Plant Syst Evol 145:55–77. https://doi.org/10.1007/BF00984031 Gutowski JM (1990) Pollination of the orchid Dactylorhiza fuchsii by longhorn beetles in primeval forests of Northeastern Poland. Biol Conserv 51:287–297. https://doi.org/10.1016/0006-3207(90)90114-5 Jia LB, Huang SQ (2022) An examination of nectar production in 34 species of Dendrobium indicates that deceptive pollination in the orchids is not popular. J Syst Evol 60:1371–1377. https://doi.org/10.1111/jse.12799 Johnson SD (1995) Observations of hawkmoth pollination in the South African orchid Disa cooperi . Nord J Bot 15:121–125. https://doi.org/10.1111/j.1756-1051.1995.tb00128.x Jürgens A, Bosch SR, Webber AC, et al (2009) Pollination biology of Eulophia alta ( Orchidaceae) in Amazonia: Effects of pollinator composition on reproductive success in different populations. Ann Bot 104:897–912. https://doi.org/10.1093/aob/mcp191 Käpylä M (1978) Amount and type of nectar sugar in some wild flowers in Finland. Ann Bot Fenn 15:85–88 Koivisto AM, Vallius E, Salonen V (2002) Pollination and reproductive success of two colour variants of a deceptive orchid, Dactylorhiza maculata (Orchidaceae). Nord J Bot 22:53–58. https://doi.org/10.1111/j.1756-1051.2002.tb01621.x Lipińska MM, Archila FL, Haliński ŁP, et al (2022) Ornithophily in the subtribe Maxillariinae (Orchidaceae) proven with a case study of Ornithidium fulgens in Guatemala. Sci Rep 12:5273. https://doi.org/10.1038/s41598-022-09146-4 Luyt R, Johnson SD (2001) Hawkmoth pollination of the African epiphytic orchid Mystacidium venosum , with special reference to flower and pollen longevity. Plant Syst Evol 228:49–62 Luyt RP (2002) Pollination and Evolution of the genus Mystacidium (Orchidaceae). University of Natal, South Africa Meneguzzo TEC, Carvalho BM, Batista JAN, et al (2024) Brachystele guayanensis is a Cyclopogon (Orchidaceae): notes on its biology and taxonomy. Phytotaxa 658:109–119. https://doi.org/10.11646/phytotaxa.658.1.5 Molano-Flores B (2001) Herbivory and calcium concentrations affect calcium oxalate crystal formation in leaves of Sida (Malvaceae). Ann Bot 88:387–391. https://doi.org/10.1006/anbo.2001.1492 Morrant DS, Schumann R, Petit S (2009) Field methods for sampling and storing nectar from flowers with low nectar volumes. Ann Bot 103:533–542. https://doi.org/10.1093/aob/mcn241 Naczk AM, Kowalkowska AK, Wisniewska N, et al (2018) Floral anatomy, ultrastructure and chemical analysis in Dactylorhiza incarnata / maculata complex (Orchidaceae). Bot J Linn Soc 187:512–536. https://doi.org/10.1093/botlinnean/boy027 Pais MS, Figueiredo ACS (1994) Floral nectaries from Limodorum abortivum (L.) Sw and Epipactis atropurpurea Rafin (Orchidaceae): Ultrastructural changes in plastids during the secretory process. Apidologie 25:615–626. https://doi.org/10.1051/apido:19940612 Pais MSS, Neves HJC das (1980) Sugar Content of the Nectary Exudate of Epipactis atropurpurea Rafin. Apidologie 11:39–45. https://doi.org/10.1051/apido:19800105 Percival MS (1961) Types of Nectar in Angiosperms. New Phytol 60:235–281. https://doi.org/10.1111/j.1469-8137.1961.tb06255.x Petanidou T, Van Laere A, N. Ellis W, Smets E (2006) What shapes amino acid and sugar composition in Mediterranean floral nectars? Oikos 115:155–169. https://doi.org/10.1111/j.2006.0030-1299.14487.x Peter CI, Johnson SD (2009) Reproductive biology of Acrolophia cochlearis (Orchidaceae): Estimating rates of cross-pollination in epidendroid orchids. Ann Bot 104:573–581. https://doi.org/10.1093/aob/mcn218 Phillips RD, Bohman B, Brown GR, et al (2020) A specialised pollination system using nectar-seeking thynnine wasps in Caladenia nobilis (Orchidaceae). Plant Biol 22:157–166. https://doi.org/10.1111/plb.13069 Phillips RD, Bohman B, Peakall R, Reiter N (2024) Sexual attraction with pollination during feeding behaviour: implications for transitions between specialized strategies. Ann Bot 133:273–286. https://doi.org/10.1093/aob/mcad178 Ponert J, Trávníček P, Vuong TB, et al (2016) A new species of Cleisostoma (Orchidaceae) from the Hon Ba Nature Reserve in Vietnam: A multidisciplinary assessment. PLoS One 11:. https://doi.org/10.1371/journal.pone.0150631 POWO (2024) Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. In: Http://Www.Plantsoftheworldonline.Org/. http://www.plantsoftheworldonline.org/. Accessed 1 Apr 2024 Reiter N, Bohman B, Freestone M, et al (2019) Pollination by nectar-foraging thynnine wasps in the endangered Caladenia arenaria and Caladenia concolor (Orchidaceae). Aust J Bot 67:490–500. https://doi.org/10.1071/BT19033 Reiter N, Wicks M, Pollard G, et al (2023) Improving conservation and translocation success of an endangered orchid, Caladenia xanthochila (Orchidaceae), through understanding pollination. Plant Ecol 224:715–727. https://doi.org/10.1007/s11258-023-01334-0 Salazar GA, Batista JAN, Cabrera LI, et al (2018) Phylogenetic systematics of subtribe Spiranthinae (Orchidaceae: Orchidoideae: Cranichideae) based on nuclear and plastid DNA sequences of a nearly complete generic sample. Bot J Linn Soc 186:273–303. https://doi.org/10.1093/botlinnean/box096 Shrestha M, Dyer AG, Dorin A, et al (2020) Rewardlessness in orchids: how frequent and how rewardless? Plant Biol 22:555–561. https://doi.org/10.1111/plb.13113 Silva KFO e., Melo BCV, Moreira TB, Williams TCR (2021) Darkness and low-light alter reserve mobilization during the initial growth of soybean (Glycine max (L.) Merrill). Theor Exp Plant Physiol 33:55–68. https://doi.org/10.1007/s40626-020-00194-7 Singer RB (2002) The pollination biology of Sauroglossum elatum Lindl. (Orchidaceae: Spiranthinae): Moth-pollination and protandry in neotropical Spiranthinae. Bot J Linn Soc 138:9–16. https://doi.org/10.1046/j.1095-8339.2002.00003.x Singer RB, Cocucci AA (1999) Pollination mechanism in southern Brazilian orchids which are exclusively or mainly pollinated by halictid bees. Plant Syst Evol 217:101–117. https://doi.org/10.1007/BF00984924 Singer RB, Sazima M (1999) The pollination mechanism in the “ Pelexia alliance” (Orchidaceae: Spiranthinae). Bot J Linn Soc 131:249–262. https://doi.org/10.1006/bojl.1999.0270 Stpiczyńska M, Matusiewicz J (2001) Anatomy and ultrastructure of spur nectary of Gymnadenia conopsea (L.) Orchidaceae. Acta Soc Bot Pol 70:267–272. https://doi.org/10.5586/asbp.2001.034 Swięczkowska E, Kowalkowska AK (2015) Floral nectary anatomy and ultrastructure in mycoheterotrophic plant, Epipogium aphyllum Sw. (Orchidaceae). Sci World J 2015:1–11. https://doi.org/10.1155/2015/201702 Szlachetko DL, Rutkowski P (2008) Classification of Spiranthinae, Stenorrhynchidinae and Cyclopogoninae. In: Rutkowski P, Szlachetko DL, Górniak M (eds) Phylogeny and taxonomy of the subtribes Spiranthinae, Stenorrhynchidinae and Cyclopogoninae (Spirantheae, Orchidaceae) in Central and South America. Wydawanictwo Uniwersytetu Gdańskiego, Gdańsk, pp 130–222 Szlachetko DL, Rutkowski P, Mytnik J (2005) Contributions to the taxonomic revision of the subtribes Spiranthinae, Stenorrhynchidinae and Cyclopogoninae (Orchidaceae) in Mesoamerica and the Antilles. Polish Bot Stud 20:3–387 Watteyn C, Scaccabarozzi D, Muys B, et al (2023) Sweet as Vanilla hartii : Evidence for a nectar-rewarding pollination mechanism in Vanilla (Orchidaceae) flowers. Flora Morphol Distrib Funct Ecol Plants 303: 152294. https://doi.org/10.1016/j.flora.2023.152294 Wiemer AP, Moré M, Benitez-Vieyra S, et al (2009) A simple floral fragrance and unusual osmophore structure in Cyclopogon elatus (Orchidaceae). Plant Biol 11:506–514. https://doi.org/10.1111/j.1438-8677.2008.00140.x Wilmer P (2011) Pollination and floral ecology. Princeton University Press, Princeton, USA Additional Declarations No competing interests reported. Supplementary Files MeneguzzoetalSupplementarymaterialJCHEMECOL.docx Cite Share Download PDF Status: Published Journal Publication published 28 May, 2025 Read the published version in Journal of Chemical Ecology → Version 1 posted Editorial decision: Revision requested 01 Feb, 2025 Reviews received at journal 18 Sep, 2024 Reviewers agreed at journal 09 Sep, 2024 Reviewers agreed at journal 09 Sep, 2024 Reviewers invited by journal 12 Aug, 2024 Editor assigned by journal 12 Aug, 2024 Submission checks completed at journal 08 Aug, 2024 First submitted to journal 07 Aug, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-4876023\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":341496359,\"identity\":\"f9bad87b-5ec9-4371-9f7e-09c9eda12c8c\",\"order_by\":0,\"name\":\"THIAGO E. C. MENEGUZZO\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Instituto de Pesquisas Jardim Botânico do Rio de Janeiro\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"THIAGO\",\"middleName\":\"E. C.\",\"lastName\":\"MENEGUZZO\",\"suffix\":\"\"},{\"id\":341496360,\"identity\":\"ccaa4e9a-eae5-4664-9395-0d71e3c55e2a\",\"order_by\":1,\"name\":\"SUELI M. GOMES\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Universidade de Brasília\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"SUELI\",\"middleName\":\"M.\",\"lastName\":\"GOMES\",\"suffix\":\"\"},{\"id\":341496361,\"identity\":\"dc4ed4d8-6bc8-48d7-879f-56fcf945e3ab\",\"order_by\":2,\"name\":\"JOÃO A. N. BATISTA\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Universidade Federal de Minas Gerais\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"JOÃO\",\"middleName\":\"A. N.\",\"lastName\":\"BATISTA\",\"suffix\":\"\"},{\"id\":341496362,\"identity\":\"6889fe17-7436-40d2-8377-4c13126ae686\",\"order_by\":3,\"name\":\"ANTONIO J. C. AGUIAR\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Universidade de Brasília\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"ANTONIO\",\"middleName\":\"J. C.\",\"lastName\":\"AGUIAR\",\"suffix\":\"\"},{\"id\":341496363,\"identity\":\"a77bebfb-216f-4af4-a8f2-2438610f3b33\",\"order_by\":4,\"name\":\"ALINE C. MARTINS\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"University of Michigan\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"ALINE\",\"middleName\":\"C.\",\"lastName\":\"MARTINS\",\"suffix\":\"\"},{\"id\":341496364,\"identity\":\"e8da835a-1c71-4794-b9fe-6635a310da88\",\"order_by\":5,\"name\":\"THOMAS C. R. WILLIAMS\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Universidade de Brasília\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"THOMAS\",\"middleName\":\"C. R.\",\"lastName\":\"WILLIAMS\",\"suffix\":\"\"},{\"id\":341496365,\"identity\":\"2f988031-0ee6-4437-a0cf-2a2fb8a4a3b4\",\"order_by\":6,\"name\":\"CAROLYN E. B. PROENÇA\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/0lEQVRIiWNgGAWjYLCCB0hsORBx4AFWdUggAYltDNaSgFUdDi2JDegi6IC//ezDB4ltdxjMpQ8ffFxQY5c+P+zwQ6AtdnK6Ddi1SJxJNzZIbHvGYNmXlmw841hy7sbbaQZALcnGZgewazFgSGOTSGw7zGBwhsdMmreBOXfj7ASQlgOJ23Bp4X8G12L+m7ehPt1wdvoH/FokkGxh5m04nCAvnYPfFokbz5gNEs4d5rHsYUuW5jl23HCDdE7BgQQD3H7h709jfPCh7LCcOQ/zwc88NdXy8rPTN3/4UGEnh0sLGDCyMfAYwJ16ABIsBMAfJDXyDYRUj4JRMApGwUgDAMN4XF+S6i9aAAAAAElFTkSuQmCC\",\"orcid\":\"\",\"institution\":\"Universidade de Brasília\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"CAROLYN\",\"middleName\":\"E. B.\",\"lastName\":\"PROENÇA\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2024-08-07 16:02:45\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-4876023/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-4876023/v1\",\"draftVersion\":[],\"editorialEvents\":[{\"content\":\"https://doi.org/10.1007/s10886-025-01611-4\",\"type\":\"published\",\"date\":\"2025-05-28T15:57:33+00:00\"}],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":63887257,\"identity\":\"60da1dd7-9eb5-42c0-9350-8e34b8131e78\",\"added_by\":\"auto\",\"created_at\":\"2024-09-03 11:36:46\",\"extension\":\"png\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":1669945,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eOverview of \\u003cem\\u003eCyclopogon guayanensis \\u003c/em\\u003ein Brasilia, Distrito Federal, Brazil. A. Flowering raceme at an early stage. B. Fruiting raceme. C. Population A in an urban grassland.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage2.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4876023/v1/ef9ae55e5209c245945c1164.png\"},{\"id\":63887256,\"identity\":\"669c444b-4abc-44a0-9cbd-7e72ec56be0e\",\"added_by\":\"auto\",\"created_at\":\"2024-09-03 11:36:46\",\"extension\":\"png\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":1084926,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eFlower visitors of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e apparently carrying pollinarium on the inner surface of the labrum. A and B. \\u003cem\\u003eDialictus\\u003c/em\\u003e sp. (Halictidae), male; C. \\u003cem\\u003eTetrapedia \\u003c/em\\u003esp.\\u003cem\\u003e \\u003c/em\\u003e(Apidae), male.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage3.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4876023/v1/725b539fcce7494f52dd891d.png\"},{\"id\":63887260,\"identity\":\"effdf311-b832-4a57-940e-8eca6bb80d8f\",\"added_by\":\"auto\",\"created_at\":\"2024-09-03 11:36:46\",\"extension\":\"png\",\"order_by\":3,\"title\":\"Figure 3\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":893720,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eFlower visitors of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e collecting nectar: A. \\u003cem\\u003eTetrapedia\\u003c/em\\u003esp., male, B. \\u003cem\\u003eExomalopsis \\u003c/em\\u003esp., female; C. \\u003cem\\u003eNomada\\u003c/em\\u003e sp., female, D. \\u003cem\\u003eDialictus \\u003c/em\\u003esp., male.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage4.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4876023/v1/d4ba1e282a5b763b5b7e96de.png\"},{\"id\":63887261,\"identity\":\"bb5bca9e-a8f1-49e8-964d-684580cd6a85\",\"added_by\":\"auto\",\"created_at\":\"2024-09-03 11:36:46\",\"extension\":\"png\",\"order_by\":4,\"title\":\"Figure 4\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":1001502,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eMicromorphology and histochemistry of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e floral buds and flowers (A–F, H–J, L–Q: Sudan test; G, K: control). A. Lipids absent in the floral buds. B-D. Lipids present in open flowers with pollinaria (B) and without pollinaria (C), and in senescent flowers (D). E–G. Glandular trichomes on the flower (E) and ciliate bracteoles (F–G). F–H. Idioblasts containing raphids (arrowheads) in bracteoles (F–G) and tepals (H). I. Free raphids. J. Incipient lipid secretion in the bud’s glandular trichomes. K. Trichome natural colour. L. Lipidic secretion accumulated in the periplasmatic region (arrows) of the glandular trichomes the open flower. M–N. Labellum inner surface showing papillae with non-lipidic secretion (N, arrow) in open flowers. O–P. Tetrads. Q. Unitegmic ovules. Scales: A–D: 5mm; E: 1mm; F, M: 200µm; G, J–K, N–O: 50µm; H: 300µm; I, L: 30µm; P–Q: 20µm.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage5.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4876023/v1/e278db352779a28ae5f2f1dc.png\"},{\"id\":83782894,\"identity\":\"8fbfc808-058f-4a7f-8a8d-2ed74c516634\",\"added_by\":\"auto\",\"created_at\":\"2025-06-02 16:08:12\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":5697107,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4876023/v1/06ca7cab-c1c4-47fc-896d-d2da26c3b1e1.pdf\"},{\"id\":63887259,\"identity\":\"5872515b-5456-42d3-85fb-1645ce7f0845\",\"added_by\":\"auto\",\"created_at\":\"2024-09-03 11:36:46\",\"extension\":\"docx\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":26022,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003e\\u003cbr\\u003e\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"MeneguzzoetalSupplementarymaterialJCHEMECOL.docx\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4876023/v1/3f44932cf0b6735bd2e2584d.docx\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"\\u003cp\\u003eCyclopogon Guayanensis is an Unusual Orchid With a Generalistic Pollination System and Hexose Dominant Nectar\\u003c/p\\u003e\",\"fulltext\":[{\"header\":\" Introduction\",\"content\":\"\\u003cp\\u003eThe \\u003cem\\u003ePelexia\\u003c/em\\u003e alliance (subtribe Spiranthinae, tribe Cranichideae, subfamily Orchidoideae, family Orchidaceae; Chase et al. \\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e2015\\u003c/span\\u003e) is a clade of seven genera and about 280 species (Salazar et al. \\u003cspan citationid=\\\"CR58\\\" class=\\\"CitationRef\\\"\\u003e2018\\u003c/span\\u003e; POWO \\u003cspan citationid=\\\"CR55\\\" class=\\\"CitationRef\\\"\\u003e2024\\u003c/span\\u003e). This alliance is exclusively Neotropical, widely distributed, and is dominated by its three largest genera: \\u003cem\\u003eCyclopogon\\u003c/em\\u003e C.Presl, \\u003cem\\u003ePelexia\\u003c/em\\u003e Poit. ex Lindl. and \\u003cem\\u003eSarcoglottis\\u003c/em\\u003e C.Presl, which together comprise 85% of its species.\\u003c/p\\u003e \\u003cp\\u003eA recent phylogeny of subtribe Spiranthinae (Salazar et al. \\u003cspan citationid=\\\"CR58\\\" class=\\\"CitationRef\\\"\\u003e2018\\u003c/span\\u003e) revealed that the \\u003cem\\u003eCyclopogon\\u003c/em\\u003e clade is paraphyletic, i.e., it included all species of \\u003cem\\u003eCyclopogon\\u003c/em\\u003e sampled but also a nested subclade of \\u003cem\\u003eBrachystele guayanensis\\u003c/em\\u003e (Lindl.) Schltr. + \\u003cem\\u003eVeyretia\\u003c/em\\u003e Szlach. (four species sampled). All other species of \\u003cem\\u003eBrachystele\\u003c/em\\u003e Schltr., including the type, formed a monophyletic separate clade within the Spiranthinae but in another clade called the \\u003cem\\u003ePelexia\\u003c/em\\u003e clade by the authors. \\u003cem\\u003eBrachystele\\u003c/em\\u003e was thus split between the \\u003cem\\u003ePelexia\\u003c/em\\u003e clade and the \\u003cem\\u003eCyclopogon\\u003c/em\\u003e clade. This scenario suggests the occurrence of parallel evolution of vegetative and floral characters between different lineages of the Spiranthinae that have caused them to be put into the same genus based on morphological characters (e.g., Szlachetko and Rutkowski \\u003cspan citationid=\\\"CR66\\\" class=\\\"CitationRef\\\"\\u003e2008\\u003c/span\\u003e). \\u003cem\\u003eBrachystele guayanensis\\u003c/em\\u003e has been recently transferred to \\u003cem\\u003eCyclopogon\\u003c/em\\u003e (Meneguzzo et al. \\u003cspan citationid=\\\"CR43\\\" class=\\\"CitationRef\\\"\\u003e2024\\u003c/span\\u003e) based on molecular, morphological and the ecological results that are presented here.\\u003c/p\\u003e \\u003cp\\u003eIn 2020 and 2021, the population of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e from which the sample for the phylogenetic study of the Spiranthinae (Salazar et al. \\u003cspan citationid=\\\"CR58\\\" class=\\\"CitationRef\\\"\\u003e2018\\u003c/span\\u003e) was collected flowered. A second population was also found; both populations were in urban grasslands in Brasilia, Distrito Federal, Brazil. This provided us with an opportunity to study its floral biology, pollinators, micromorphology and histochemistry, unknown until now. A large quantity of data on the floral biology of subtribe Spiranthinae has been amassed by Rodrigo Singer and collaborators (Singer and Cocucci \\u003cspan citationid=\\\"CR62\\\" class=\\\"CitationRef\\\"\\u003e1999\\u003c/span\\u003e; Singer and Sazima \\u003cspan citationid=\\\"CR63\\\" class=\\\"CitationRef\\\"\\u003e1999\\u003c/span\\u003e; Singer \\u003cspan citationid=\\\"CR61\\\" class=\\\"CitationRef\\\"\\u003e2002\\u003c/span\\u003e; Buzatto \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e2014\\u003c/span\\u003e). Also, this data has been recently reviewed and interpreted within a phylogenetic framework (Buzatto et al. \\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003eThe hypothesis for our study was that its floral biology would show: 1) similarities to \\u003cem\\u003eCyclopogon\\u003c/em\\u003e due to a shared phylogeny; 2) differences from \\u003cem\\u003eCyclopogon\\u003c/em\\u003e, possibly due to parallel evolution with \\u003cem\\u003eBrachystele sensu stricto\\u003c/em\\u003e.\\u003c/p\\u003e\"},{\"header\":\"Methods and materials\",\"content\":\"\\u003cp\\u003e \\u003cem\\u003eFloral Biology.\\u003c/em\\u003e A flowering population estimated to be of several hundred individuals over an area of c. 0.5 km\\u003csup\\u003e2\\u003c/sup\\u003e was found in Bras\\u0026iacute;lia (Population A, 15\\u003csup\\u003eo\\u003c/sup\\u003e 45\\u0026rsquo; 55\\u0026rdquo; S, 47\\u003csup\\u003eo\\u003c/sup\\u003e 52\\u0026rsquo; 47\\u0026rdquo; W) on the 7th November 2020 (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e), followed by a second much smaller population of a few dozen individuals on the 9th of November 2020 (Population B, 15\\u003csup\\u003eo\\u003c/sup\\u003e 44\\u0026rsquo; 07\\u0026rdquo; S, 47\\u003csup\\u003eo\\u003c/sup\\u003e 53\\u0026rsquo; 24\\u0026rdquo; W)). These two populations were observed between the 8th and 13th November 2020; the first population flowered again in the following year (flowering individuals were first detected on the 21st October 2021) and was observed between 27th October and 9th November 2021.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eIn the Distrito Federal, the day length difference during the flowering period was minimal; sunrise on 20 October was 05:40 and sunset 18:11, and on the 15 November sunrise was 5:30 and sunset 18:22. Observations were made between 6:00\\u0026ndash;7:00 to 17:00\\u0026ndash;18:00 (12 hourly intervals) lasting at least 40 min per hour interval, except for intervals 15:00\\u0026ndash;16:00 (35 min) and interval 17h00\\u0026ndash;18h00 (25 min), totalling 610 min (just over 10 man hours).\\u003c/p\\u003e \\u003cp\\u003eVisitor behaviour was observed, including possible resource collection, insect body parts touching fertile organs, and adherence position of the pollinarium. Whenever possible, digital images and videos were recorded, and insects were collected for identification. Collected insects were dried, pinned, labelled, and deposited in the Entomological Collection of the Departamento de Zoologia, Universidade de Bras\\u0026iacute;lia, Brazil. They were identified by authors ACA and ACM (see also acknowledgements). A voucher specimen from plant population 1 was collected and is deposited in the UB herbarium (\\u003cem\\u003eC.E.B. Proen\\u0026ccedil;a 5579\\u003c/em\\u003e) at the Universidade de Bras\\u0026iacute;lia, Brazil, available from the Species Link collection network (\\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttps://specieslink.net/search/\\u003c/span\\u003e\\u003cspan address=\\\"https://specieslink.net/search/\\\" targettype=\\\"URL\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003e \\u003cem\\u003eMicromorphology and Histochemistry.\\u003c/em\\u003e Five flowering plants were collected and stored in wet paper at 8\\u003csup\\u003eo\\u003c/sup\\u003e C for c. 48 h. For each plant, two samples were taken from proximal to distal portions of the inflorescence: 1) pre-anthetic buds adjacent to open flowers; 2) open flowers with attached pollinaria; 3) open flowers without pollinaria; 4) old flowers/developing fruits with dry, brown corollas. Four repetitions of these procedures were done, each for a different individual. Samples were immersed in Sudan IV for 15 min, quickly washed in 70% ethanol, immersed in water and photographed using a Zeiss Photomicroscope with an image capture system. Non-treated flowers were also imaged.\\u003c/p\\u003e \\u003cp\\u003eSince we were unable to detect floral nectar in the field, an inflorescence with buds and open flowers was cut and the stem put in water in the field and taken to the laboratory. After two days, ten freshly opened flowers were removed, dissected, and examined for nectar under a stereomicroscope since corolla tubes were too narrow to allow insertion of microcapillary tubes. As no nectar droplets were detected, the labella were removed and soaked in 5 mL of distilled water, according to the washing method (agitated for 1 min, allowed to soak c. 20 min and frozen) as suggested by Morrant et al. (\\u003cspan citationid=\\\"CR45\\\" class=\\\"CitationRef\\\"\\u003e2009\\u003c/span\\u003e) as one of the preferrable methods of collecting nectar from flowers with low nectar volume. We were stimulated to try this method, first suggested by K\\u0026auml;pyl\\u0026auml; (\\u003cspan citationid=\\\"CR38\\\" class=\\\"CitationRef\\\"\\u003e1978\\u003c/span\\u003e), by obvious nectar foraging by floral visitors. The solution was later unfrozen and an aliquot of 100\\u0026micro;L was taken (without labella) and then vortexed briefly; this was then centrifuged at 17000 g for 20 min to remove particles and subjected to High Performance Anion Exchange (HPAE) analysis of sugars. Sugars were separated and detected using a Dionex ICS 3000 HPAE equipped with a Carbopac PA10 column and electrochemical detector. The separation was performed using a sodium hydroxide gradient at 0.2 mL.min\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e exactly as described in Silva et al. (\\u003cspan citationid=\\\"CR60\\\" class=\\\"CitationRef\\\"\\u003e2021\\u003c/span\\u003e). Sugars were identified and quantified by comparison with a calibration curve constructed using authentic standards.\\u003c/p\\u003e\"},{\"header\":\"RESULTS\",\"content\":\"\\u003cp\\u003e \\u003cem\\u003eFloral biology.\\u003c/em\\u003e The floral scape of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e is a spike-like raceme c. 15 to 30 cm high. Flowers are resupinate and arranged in a dense ascending spiral, so that the left side of each labellum is adjacent to, and sometimes touches, the lateral sepal of the flower below it (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e). The corolla is creamy-white with the tube externally greenish and internally cream or pale yellow. Flowers are zygomorphic and are c. 3 mm high and 2.5 mm across; the entrance to the tube is c. 1 mm wide; the labellum presents a central, slightly yellowish groove; pollinia are pale yellow and visible; no nectar was observed.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eThe flowers of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e were visited between 8 AM and 5 PM (Supporting Information, Table \\u003cspan refid=\\\"MOESM1\\\" class=\\\"InternalRef\\\"\\u003eS1\\u003c/span\\u003e). We observed at least 10 species of insects, mainly bees but also syrphid flies, of which four can be considered pollinators (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e, Table\\u0026nbsp;\\u003cspan refid=\\\"Tab1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e). The pollinators of \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e are small, generalist bees from non-related groups (two families). Four species of bees from the genera \\u003cem\\u003eExomalopsis\\u003c/em\\u003e, \\u003cem\\u003eNomada\\u003c/em\\u003e and \\u003cem\\u003eTetrapedia\\u003c/em\\u003e (Apidae) and \\u003cem\\u003eDialictus\\u003c/em\\u003e (Halictidae) were observed with one or more pollinaria attached to their bodies, reinforcing their role as pollinators (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e); pollinators had in common similar body sizes and tongue lengths. The position and angle of the pollinaria in the images suggest that they are adhered to the ventral surface of the bee labrum (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e) as in \\u003cem\\u003eCyclopogon\\u003c/em\\u003e. Unfortunately, captured visitors lacked pollinaria, so we are reluctant to state this unequivocally; it is also possible that they are adhered to the clypeus or proboscis. Several other Halictid bees were also observed visiting and might be pollinators but were captured as they approached or landed on the flowers or lacked pollinaria: \\u003cem\\u003eAugochlora\\u003c/em\\u003e sp., \\u003cem\\u003eAugochloropsis\\u003c/em\\u003e sp., and \\u003cem\\u003eNeocorynura pseudobaccha\\u003c/em\\u003e (Cockerell, 1901). Apparently, all visitors were searching for nectar (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e), collecting it with their tongues. In spite of the visitors\\u0026rsquo; relatively small sizes, they could not enter the very small flowers of \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e, so only the head was inserted.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eFloral visitors of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e populations in the Distrito Federal (Brazil) during the month of November (2020) and October/November (2021). Only days with visits shown (see Table S2 for complete record of observation periods).\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eDate\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003ePeriods\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eTotal time (minutes) and observer\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eVisitors/Pollinators\\u003c/p\\u003e \\u003cp\\u003eC\\u0026thinsp;=\\u0026thinsp;captured; O\\u0026thinsp;=\\u0026thinsp;observed; P\\u0026thinsp;=\\u0026thinsp;photographed; V\\u0026thinsp;=\\u0026thinsp;Video recorded.\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e8 Nov 2020 (Pop 1)\\u003c/p\\u003e \\u003cp\\u003e(see Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e07:45\\u0026ndash;08:05\\u003c/p\\u003e \\u003cp\\u003e12:20\\u0026ndash;12:40\\u003c/p\\u003e \\u003cp\\u003e16:40\\u0026ndash;17:00\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e20 (CEBP)\\u003c/p\\u003e \\u003cp\\u003e20 (CEBP)\\u003c/p\\u003e \\u003cp\\u003e20 (CEBP)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eApis mellifera\\u003c/em\\u003e Linnaeus, 1758 (O, did not land).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eTrigona spinipes\\u003c/em\\u003e (Fabricius, 1793) (V).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eExomalopsis\\u003c/em\\u003e sp. 1 (C).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e9 Nov 2020\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003epopulation 1 destroyed by urban mowing\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e11 Nov 2020 (Pop 2)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e08:28\\u0026ndash;09:10\\u003c/p\\u003e \\u003cp\\u003e13:58\\u0026ndash;14:45\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e42 (CEBP)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eno visits\\u003c/p\\u003e \\u003cp\\u003eBee, unidentified (O); Syrphidae flies (O).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e11 Nov 2020 (Pop 2)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e11:00\\u0026ndash;12:00\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e60 (ACM \\u0026amp; AJCA)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eExomalopsis\\u003c/em\\u003e sp. 1, female with pollinarium on mouthparts (P).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e12 Nov 2020 (Pop 2)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e08:30\\u0026ndash;09:30\\u003c/p\\u003e \\u003cp\\u003e13:30\\u0026ndash;14:30\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e120 (AJCA)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eExomalopsis\\u003c/em\\u003e sp. 1, female (O).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eNomada\\u003c/em\\u003e, sp., female with pollinarium on mouthparts (P).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eTrigona spinipes\\u003c/em\\u003e (O).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eExomalopsis\\u003c/em\\u003e sp. 1, female (O).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eNanotrigona testaceicornis\\u003c/em\\u003e le Peletier, 1836 (O)\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eExomalopsis\\u003c/em\\u003e sp. 2, female (O).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eDialictus\\u003c/em\\u003e sp., male with pollinarium on mouthparts (P).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eTetrapedia\\u003c/em\\u003e sp., male with pollinarium on mouthparts (P).\\u003c/p\\u003e \\u003cp\\u003eSyrphidae flies (O).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e13 Nov 2020 (Pop 2)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e13:30\\u0026ndash;14:30\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e60 (AJCA)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eDialictus\\u003c/em\\u003e sp., female (O).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eParatrigona lineata\\u003c/em\\u003e (le Peletier, 1836) (O).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eExomalopsis\\u003c/em\\u003e sp. 2, male (O).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e21 Oct 2021\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e2021 flowering population detected.\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e27 Oct 2021 (Pop 1)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e16:40\\u0026ndash;17:05\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e25 (CEBP)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eDialictus\\u003c/em\\u003e sp. (C).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e28 Oct 2021 (Pop 1)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e07:45\\u0026ndash;08:05\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e20 (CEBP)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003ecf. \\u003cem\\u003eTrigona\\u003c/em\\u003e (V).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e30 Oct 2021 (Pop 1)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e10:30\\u0026ndash;11:00\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e30 (CEBP)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eNeocorynura pseudobaccha\\u003c/em\\u003e (Cockerell, 1901), male (P).\\u003c/p\\u003e \\u003cp\\u003e\\u003cem\\u003eAugochlora\\u003c/em\\u003e sp., male (C).\\u003c/p\\u003e \\u003cp\\u003eHemiptera (O).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e01 Nov 2021 (Pop 1)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e07:00\\u0026ndash;07:30\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e30 (CEBP)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eAugochloropsis\\u003c/em\\u003e sp. (P).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e02 Nov 2021 (Pop 1)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e12:30\\u0026ndash;12:40\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e10 (CEBP)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eDialictus\\u003c/em\\u003e sp., male (C).\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e09 Nov 2021 (Pop 1)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e6:50\\u0026ndash;7:00\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e10 (CEBP)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eAugochloropsis\\u003c/em\\u003e sp. (P) sleeping.\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cem\\u003eMicromorphology and Histochemistry.\\u003c/em\\u003e The micromorphological analysis as well as the histochemical results of the Sudam IV test are presented in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e. Tector trichomes were not observed on the inflorescence. Two types of glandular trichomes were present, one pedunculate with a secretory head, and the other of the papillae type. The bracteoles are ciliate with 4\\u0026ndash;8\\u0026ndash;celled glandular trichomes (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eF\\u0026ndash;G). The sepals present (2\\u0026ndash;3)4(\\u0026ndash;5)\\u0026ndash;celled glandular trichomes on the abaxial (external) surface that are dense along the midveins but thin out towards the distal regions. Lipid secretion from the glandular trichomes is insignificant in pre-anthetic buds (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eA, J), but intense in open (perhaps male-phase?) flowers with the pollinarium still attached (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eB, L), as well as in the flowers in which the pollinarium is absent (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eC) and in the senescent flowers (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eD), i.e., the trichomes persist and do not fall off or dry out, at least in the senescent flowers immediately below the open flowers.\\u003c/p\\u003e \\u003cp\\u003eThe petals are covered with one-celled papillae on the inner surface; these papillae are mostly short (c. 1.5 times as long as wide) except on the labellum on which the papillae are longer, c. 2\\u0026ndash;3 times as long as wide (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eM\\u0026ndash;N). In both types of papillae, periplasmic spaces were observed to form within the cells, but these are much more developed in the long than in the short papillae. The contents of these periplasmic papilla spaces did not stain with Sudan IV (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eN, arrow). Sepals and petals form a short floral tube (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eH) and have many scattered idioblasts with raphids (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eH, head-arrow, I), as do the bracteoles (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eF\\u0026ndash;G, head-arrow). The pollen within the squashed pollinaria is shed in tetrads (Fig.\\u0026nbsp;4OP) and the ovule is unitegmic (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eQ).\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cem\\u003eNectar composition.\\u003c/em\\u003e The sugar composition from HPAE analysis of the solution obtained from the 10 labella was: 5.5% sucrose, 53.8% glucose, and 40.7% fructose by mass. No other monosaccharides or oligosaccharides were detected. A total of 94.5% of the sugar in the sample was therefore hexose.\\u003c/p\\u003e\"},{\"header\":\"DISCUSSION\",\"content\":\"\\u003cp\\u003eThe floral biology of the Spiranthinae was stated to be \\u0026ldquo;much more complex than cursory comparisons suggest\\u0026rdquo; (Salazar et al. \\u003cspan\\u003e2018\\u003c/span\\u003e: 277). A recent review of the floral biology of \\u003cem\\u003ePelexia\\u003c/em\\u003e clade (Buzatto et al. \\u003cspan\\u003e2022\\u003c/span\\u003e) states that orchids in this clade are pollinated mainly by bees, especially those from the family Halictidae, which are attracted by the nectar produced as a reward (Table\\u0026nbsp;\\u003cspan\\u003e2\\u003c/span\\u003e). The flowers are, in general, small for the family, white, with floral parts covered with carpets of glandular hairs. \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e conforms very well to this pattern but stands out due to the wide taxonomic diversity of both pollinators and visitors, and lack of visible nectar.\\u003c/p\\u003e\\n\\u003cp\\u003eBee visitation observed in \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e closely follows the description given by Singer and Cocucci (\\u003cspan\\u003e1999\\u003c/span\\u003e) for \\u003cem\\u003eC. diversifolius\\u003c/em\\u003e (Cogn.) Schltr., with pollinia possibly adhering to the underside of the bee labrum. These authors hypothesized that \\u003cem\\u003eC. diversifolius\\u003c/em\\u003e, as well as the other two non-related species they studied [\\u003cem\\u003eCampylocentrum aromaticum\\u003c/em\\u003e Barb.Rodr. and \\u003cem\\u003ePrescottia densiflora\\u003c/em\\u003e (Brong.) Lindl.] are pollinated mainly by Halictid bees and well-adapted for \\u0026ldquo;the particular swivel proboscis mechanism of the halictid bees for pollinaria removal and deposition\\u0026rdquo; (Singer and Coccuci 1999: 112). In \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e, although halictid bees were present, their role as pollinators was overshadowed by the Apidae, i.e. \\u003cem\\u003eExomalopsis\\u003c/em\\u003e, \\u003cem\\u003eTetrapedia\\u003c/em\\u003e and \\u003cem\\u003eNomada\\u003c/em\\u003e (observed bearing pollinaria) and by stingless bees as visitors. This did not seem to be associated to any significant differences in bee body size, pollinaria attachment, or behaviour. We suggest this could be, at least in part, a product of the different bee fauna in our study area. Halictidae are highly abundant, surpassing the Apidae in several surveys (Martins et al. 2013) in subtropical and temperate regions of South America (where other studies of \\u003cem\\u003eCyclopogon\\u003c/em\\u003e pollinators have been done; e.g., Singer and Coccuci 1999; Singer and Sazima \\u003cspan\\u003e1999\\u003c/span\\u003e; Galetto et al. \\u003cspan\\u003e1997\\u003c/span\\u003e;Benitez-Vieyra et al. \\u003cspan\\u003e2006\\u003c/span\\u003e).\\u003c/p\\u003e\\n\\u003cp\\u003eBuzatto et al. (\\u003cspan\\u003e2022\\u003c/span\\u003e) noted changes in the adherence position of pollinaria on the bee labrum in the phylogenetic tree of species in the \\u003cem\\u003ePelexia\\u003c/em\\u003e clade using ancestral character state reconstruction. These authors hypothesized that the ancestor of the \\u003cem\\u003ePelexia\\u003c/em\\u003e alliance had ventrally viscous pollinia and noted that the two most basal species \\u003cem\\u003eCoccineorchis cernua\\u003c/em\\u003e (Lindl.) Garay and \\u003cem\\u003eSauroglossum elatum\\u003c/em\\u003e Lindl. (respectively pollinated by hummingbirds and lepidopterans) retained this ancestral character. The shift to hymenopteran pollination was accompanied by a shift from ventral to dorsal pollinia that adhere to the ventral surface of the bee labrum in \\u003cem\\u003eCyclopogon comosus\\u003c/em\\u003e (Rchb.f.) Burns-Bal. \\u0026amp; E.W.Greenw., \\u003cem\\u003ePachygenium bonariensis\\u003c/em\\u003e (Lindl.) Schltr., \\u003cem\\u003ePelexia adnata\\u003c/em\\u003e (Sw.) Poit. ex Rich., \\u003cem\\u003eSarcoglottis acaulis\\u003c/em\\u003e (Sm.) Schltr., and with a reversal to ancestral ventral pollinia in \\u003cem\\u003eBrachystele unilateralis\\u003c/em\\u003e (the type species of the genus), i.e., a member of \\u003cem\\u003eBrachystele sensu stricto\\u003c/em\\u003e. Thus, if adherence of pollinia to the inner surface of the bee labrum in \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e is confirmed in future captured bees, its transfer to \\u003cem\\u003eCyclopogon\\u003c/em\\u003e first suggested by molecular markers (Salazar et al. \\u003cspan\\u003e2018\\u003c/span\\u003e) will be further strengthened and will also sustain the evolutionary scenario proposed by Buzatto et al. (\\u003cspan\\u003e2022\\u003c/span\\u003e) for this character.\\u003c/p\\u003e\\n\\u003cp\\u003eWhen commenting on the position of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e in the Spiranthinae phylogenetic tree, Salazar et al. (\\u003cspan\\u003e2018\\u003c/span\\u003e: 296) noted the difference in flower size between the \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e (then \\u003cem\\u003eBrachystele guayanensis\\u003c/em\\u003e) and \\u003cem\\u003eVeyretia\\u003c/em\\u003e spp. and stated that: \\u0026ldquo;upon close examination, it is evident that its flowers have the two-chambered nectary of \\u003cem\\u003eVeyretia\\u003c/em\\u003e (although more shallowly so in \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e, in proportion to its noticeable reduction in flower size). This shallow two-chambered nectary was not seen.\\u003c/p\\u003e\\n\\u003cp\\u003eAbundant nectar is reported for some \\u003cem\\u003eCyclopogon\\u003c/em\\u003e species (Singer and Cocucci \\u003cspan\\u003e1999\\u003c/span\\u003e; Wiemer et al. \\u003cspan\\u003e2009\\u003c/span\\u003e), but this was not the case of \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e, in which neither the capillary tube and nor paper filter methodologies were capable of collecting nectar. Nectar is secreted by the papillae on the inner surface of the labellum, particularly along its central groove, in minute quantities. Similar papillae have been detected in \\u003cem\\u003eC. apricus\\u003c/em\\u003e (Adachi \\u003cspan\\u003e2015\\u003c/span\\u003e) and \\u003cem\\u003eC. dutrae\\u003c/em\\u003e (Galetto et al. \\u003cspan\\u003e1997\\u003c/span\\u003e). Nectar secreting papillae on the inner surface of the labellum have also been found in the ghost orchid, \\u003cem\\u003eEpipogium aphyllum\\u003c/em\\u003e Sw., subtribe Epipogiinae, tribe Gastrodieae, subfamily Epidendroideae, by Swięczkowska and Kowalkowska (\\u003cspan\\u003e2015\\u003c/span\\u003e), a northern temperate mycotrophic orchid pollinated by \\u003cem\\u003eBombus\\u003c/em\\u003e bees. Nectar is secreted along the central groove of the labellum of another mycotrophic orchid, European \\u003cem\\u003eEpipactis atropurpurea\\u003c/em\\u003e Raf. (Pais and Figueiredo \\u003cspan\\u003e1994\\u003c/span\\u003e), tribe Neottiae, subfamily Epidendroideae (Chase et al. \\u003cspan\\u003e2015\\u003c/span\\u003e), which has, however, epidermal nectariferous tissue along the groove and not papillae.\\u003c/p\\u003e\\n\\u003cp\\u003eNectariferous tissue is composed of epidermal, specialized parenchymatic cells present on the surfaces of plant tissue that are usually either elevated or sunken (Fahn \\u003cspan\\u003e1988\\u003c/span\\u003e; Galetto et al. \\u003cspan\\u003e1997\\u003c/span\\u003e). In many orchids, the nectariferous tissue contains starch grains in the pre-secretory stage, which is the energy source to produce the nectar (Pais and Figueiredo \\u003cspan\\u003e1994\\u003c/span\\u003e; Stpiczyńska and Matusiewicz \\u003cspan\\u003e2001\\u003c/span\\u003e). Starch grains are frequent in angiosperm nectaries, and vascular bundles also can occur, although not necessarily (Fahn \\u003cspan\\u003e1988\\u003c/span\\u003e, \\u003cspan\\u003e1989\\u003c/span\\u003e). Nectar-secreting papillae (secreting minute quantities of nectar) have also recorded the \\u003cem\\u003eDactylorhiza maculata\\u003c/em\\u003e complex, tribe Orchidieae, subfamily Orchidoideae, but these are in the spur (Naczk et al. \\u003cspan\\u003e2018\\u003c/span\\u003e) not on the labellum. Papillae secreting \\u0026ldquo;floral rewards\\u0026rdquo; (a mixture of carbohydrates, lipids and proteins that feed its midge pollinators - Ceratopogonidae, Diptera) have also been recorded on the labellum of the neotropical genus \\u003cem\\u003eTrichosalpinx\\u003c/em\\u003e Luer, subtribe Pleurothallidinae, tribe Epidendreae, subfamily Epidendroideae (Bogar\\u0026iacute;n et al. \\u003cspan\\u003e2018\\u003c/span\\u003e). Thus, the exact combination of nectariferous papillae on the inner surface of a labellum that does not form a spur (Fig.\\u0026nbsp;\\u003cspan\\u003e4\\u003c/span\\u003eM-N, arrows), associated to the confirmed presence of nectar sugars is, as far as we are aware, a novelty in subfamily Orchidoideae. Papillae conclusively shown to produce nectar have been recorded in the Orchidoideae, but these are all within spurs, i.e., in several genera of subfamily Orchidoideae, subtribe Orchidinae (Bell et al. \\u003cspan\\u003e2009\\u003c/span\\u003e). In spurless \\u003cem\\u003eCyclopogon apricus\\u003c/em\\u003e, similar papillae have been detected and these were interpreted as nectaries (Adachi \\u003cspan\\u003e2015\\u003c/span\\u003e). Field studies on the reproductive biology of \\u003cem\\u003eC. apricus\\u003c/em\\u003e have been done and have shown that it secretes an exsudate considered by the authors to be nectar (Sazima and Cocucci 1999). We consider it highly likely that the secretion produced by \\u003cem\\u003eC. apricus\\u003c/em\\u003e is nectar, and that its papillae are analogous to the nectariferous papillae of \\u003cem\\u003eC. guayanensis.\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe early literature stated that floral nectar is mostly composed of varying proportions of sucrose, glucose and fructose (Percival \\u003cspan\\u003e1961\\u003c/span\\u003e; Baker and Baker \\u003cspan\\u003e1983\\u003c/span\\u003e). This composition has been widely supported by later research (Chalcoff et al. \\u003cspan\\u003e2017\\u003c/span\\u003e), although other components, such as amino acids, can also be important in the plant-pollinator interaction (Gottsberger et al. \\u003cspan\\u003e1984\\u003c/span\\u003e; Petanidou et al. \\u003cspan\\u003e2006\\u003c/span\\u003e; Brzosko and Mirski \\u003cspan\\u003e2021\\u003c/span\\u003e). Baker and Baker (\\u003cspan\\u003e1983\\u003c/span\\u003e) proposed a classification of floral nectar into four types based on an \\u0026ldquo;r\\u0026rdquo; ratio of sucrose/fructose\\u0026thinsp;+\\u0026thinsp;glucose: 1) \\u003cem\\u003esucrose dominant\\u003c/em\\u003e (r\\u0026thinsp;\\u0026gt;\\u0026thinsp;0.99); 2) \\u003cem\\u003esucrose rich\\u003c/em\\u003e (r\\u0026thinsp;=\\u0026thinsp;0.5\\u0026ndash;0.99); 3) \\u003cem\\u003ehexose rich\\u003c/em\\u003e (r\\u0026thinsp;=\\u0026thinsp;0.1\\u0026ndash;0.5); 4) \\u003cem\\u003ehexose dominant\\u003c/em\\u003e (r\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.1). Floral nectar sugar composition (and its associated ecological drivers) were recently reviewed for the angiosperms by Chalcoff et al. (\\u003cspan\\u003e2017\\u003c/span\\u003e) and for the Orchidaceae by Brzosko and Mirski (\\u003cspan\\u003e2021\\u003c/span\\u003e).\\u003c/p\\u003e\\n\\u003cp\\u003eThe nectar of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e is the second record of a hexose-dominant nectar (type 4 in the system of Baker and Baker \\u003cspan\\u003e1983\\u003c/span\\u003e) in the Orchidaceae. The first published record of a hexose dominant nectar in the Orchidaceae is very recent, of \\u003cem\\u003ePrasophyllum innubum\\u003c/em\\u003e D.L. Jones (Hayashi et al. 2024). \\u003cem\\u003eP. innubum\\u003c/em\\u003e shows remarkable similarities to \\u003cem\\u003eC. guayanense\\u003c/em\\u003e (Table\\u0026nbsp;\\u003cspan\\u003e3\\u003c/span\\u003e). A taxonomically updated list of nectar types in the Orchidaceae, mostly based on Chalcoff et al. (\\u003cspan\\u003e2017\\u003c/span\\u003e) and Brzosko and Mirski (\\u003cspan\\u003e2021\\u003c/span\\u003e) with some additional records, is presented in Table\\u0026nbsp;\\u003cspan\\u003e2\\u003c/span\\u003e.\\u003c/p\\u003e\\n\\u003ctable border=\\\"1\\\"\\u003e\\n \\u003ccaption language=\\\"En\\\"\\u003e\\n \\u003cdiv\\u003eTable 2\\u003c/div\\u003e\\n \\u003cdiv\\u003e\\n \\u003cp\\u003eOrchidaceae with known nectar composition and their pollinator groups ordered by subfamily and tribe. Nectar composition in average values when more than one individual or flower was sampled per taxon. EP\\u0026thinsp;=\\u0026thinsp;subfamily Epidendroideae; OR\\u0026thinsp;=\\u0026thinsp;subfamily Orchidoideae; VA\\u0026thinsp;=\\u0026thinsp;subfamily Vanilloideae; Coll\\u0026thinsp;=\\u0026thinsp;tribe Collabieae; Cran\\u0026thinsp;=\\u0026thinsp;tribe Cranichideae; Cymb\\u0026thinsp;=\\u0026thinsp;tribe Cymbidieae; Dend\\u0026thinsp;=\\u0026thinsp;tribe Dendrobieae; Diur\\u0026thinsp;=\\u0026thinsp;tribe Diurideae; Neot\\u0026thinsp;=\\u0026thinsp;tribe Neottieae; Orch\\u0026thinsp;=\\u0026thinsp;tribe Orchideae; Vand\\u0026thinsp;=\\u0026thinsp;tribe Vandeae; Vani\\u0026thinsp;=\\u0026thinsp;tribe Vanilleae. * name updated to follow Plants of the World Online (https://powo.science.kew.org\\u003cspan type=\\\"Underline\\\" name=\\\"Emphasis\\\"\\u003e);\\u003c/span\\u003e r\\u0026thinsp;=\\u0026thinsp;sucrose/(fructose\\u0026thinsp;+\\u0026thinsp;glucose); nectar class follows Baker \\u0026amp; Baker (1983).\\u003c/p\\u003e\\n \\u003cdiv\\u003e\\n \\u003cp\\u003eAdapted from Brzosko \\u0026amp; Mirsky (2021) and Chalcoff et al. (2017) with additions.\\u003c/p\\u003e\\n \\u003c/div\\u003e\\n \\u003c/div\\u003e\\n \\u003c/caption\\u003e\\n \\u003cthead\\u003e\\n \\u003ctr\\u003e\\n \\u003cth align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHigher taxa\\u003c/p\\u003e\\n \\u003c/th\\u003e\\n \\u003cth align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eSpecies, r value and nectar class\\u003c/p\\u003e\\n \\u003c/th\\u003e\\n \\u003cth align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eVisitors\\u003c/p\\u003e\\n \\u003c/th\\u003e\\n \\u003cth align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eReferences\\u003c/p\\u003e\\n \\u003c/th\\u003e\\n \\u003c/tr\\u003e\\n \\u003c/thead\\u003e\\n \\u003ctbody\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Coll\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCalanthe angustifolia\\u003c/em\\u003e (Blume) Lindl.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;3.27\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eUnknown\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eFreeman et al. (1991)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Cymb\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eEulophia alta\\u003c/em\\u003e (L.) Fawc. \\u0026amp; Rendle\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;0.8\\u0026thinsp;=\\u0026thinsp;sucrose rich\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Bees)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eJ\\u0026uuml;rgens et al. (2009)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Cymb\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eEulophia cochlearis\\u003c/em\\u003e Lindl. *\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;2.33\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Bees)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003ePeter \\u0026amp; Johnson (2009)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Cymb\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eMaxillaria anceps\\u003c/em\\u003e Ames \\u0026amp; C.Schweinf.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;70.86\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Bees)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eDavies et al. (2005)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Cymb\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eOrnithidium fulgens\\u003c/em\\u003e ((Rchb.f.) L.O.Williams\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;13.7\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHummingbirds\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eLipińska et al. (2022)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Dend\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eDendrobium\\u003c/em\\u003e spp (34 species from SE Asia)\\u003c/p\\u003e\\n \\u003cp\\u003esucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Bees)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eJia \\u0026amp; Huang (2022)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Neot\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eEpipactis helleborine\\u003c/em\\u003e (L.) Crantz\\u003c/p\\u003e\\n \\u003cp\\u003er (natural areas)\\u0026thinsp;=\\u0026thinsp;1.5\\u0026ndash;2.5\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003cp\\u003er (disturbed areas)\\u0026thinsp;=\\u0026thinsp;0.7\\u0026thinsp;=\\u0026thinsp;sucrose rich\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera (mainly)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eBrzosko et al. (2023)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Neot\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eEpipactis atrorubens\\u003c/em\\u003e (Hoffm.) Besser *\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;0.27\\u0026thinsp;=\\u0026thinsp;hexose rich\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eInsects\\u003c/p\\u003e\\n \\u003cp\\u003e(several orders)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003ePais \\u0026amp; Neves (1980)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Neot\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eNeottia ovata\\u003c/em\\u003e (L.) Hartm.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;0.14\\u0026ndash;0.3\\u0026thinsp;=\\u0026thinsp;hexose rich\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eInsects\\u003c/p\\u003e\\n \\u003cp\\u003e(several orders)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eBrzosko et al. (2021)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Vand\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCleisostoma lecongkietii Tich \\u0026amp; Aver. *\\u003c/em\\u003e\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;20.89\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Bees)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003ePonert et al. (2016)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eEP, Vand\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eRhipidoglossum caffrum\\u003c/em\\u003e (Bolus) Farminh\\u0026atilde;o \\u0026amp; St\\u0026eacute;vart *\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;4.26\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eLepidoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Moths)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eLuyt (2002)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Cran\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCyclopogon dutrae\\u003c/em\\u003e Schltr.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;8.17\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera (Halictidae)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGaletto et al. (1997)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eO, Cran\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e (Lindl.) B.M. Carvalho \\u0026amp; Meneguzzo\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;0.06\\u0026thinsp;=\\u0026thinsp;hexose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera, Diptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Apidae, Halictidae) (Syrphidae)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eThis study\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Cran\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eGoodyera repens\\u003c/em\\u003e (L.) R.Br.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;0.18\\u0026ndash;0.44\\u0026thinsp;=\\u0026thinsp;hexose rich\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(\\u003cem\\u003eBombus\\u003c/em\\u003e)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eBrzosko et al. (2023)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Cran\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eSacoila lanceolata\\u003c/em\\u003e (Aubl.) Garay\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;0.50\\u0026thinsp;=\\u0026thinsp;hexose rich\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eTrochilidae (Hummingbirds)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGaletto et al. (1997)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Diur.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCaladenia arenaria\\u003c/em\\u003e Fitzg.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;19.0\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Wasps)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eReiter et al. (2019)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Diur.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCaladenia colorata\\u003c/em\\u003e D.L.Jones\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;19.0\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Wasps)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eReiter et al. (2019)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Diur.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCaladenia nobilis\\u003c/em\\u003e Hopper \\u0026amp; A.P.Br.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;1.0\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Wasps)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003ePhillips et al. (2020)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Diur.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCaladenia paludosa\\u003c/em\\u003e Hopper \\u0026amp; A.P.Br.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;2.37\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Wasps)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003ePhillips et al. (2020)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Diur\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCaladenia robinsonii\\u003c/em\\u003e G.W.Carr.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;58.5\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Wasps)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003ePhillips et al. (2024)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Diur.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCaladenia versicolor\\u003c/em\\u003e G.W.Carr\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;19.0\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Wasps)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eReiter et al. (2019)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Diur.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eCaladenia xanthochila\\u003c/em\\u003e D.Beards. \\u0026amp; C.Beards.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;100\\u0026thinsp;=\\u0026thinsp;sucrose pure\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Wasps)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eReiter et al. (2023)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Diur.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003ePrasophyllum innubum\\u003c/em\\u003e D.L.Jones\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;0.01\\u0026thinsp;=\\u0026thinsp;hexose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eInsects\\u003c/p\\u003e\\n \\u003cp\\u003e(several orders)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHayashi et al. (2024)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eBonatea cassidea\\u003c/em\\u003e Sond.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;67.5\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eLepidoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Butterflies)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eBalducci et al. (2019)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eBonatea polypodantha\\u003c/em\\u003e (Rchb.f.) L.Bolus\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;4.34\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eLepidoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Moths)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eBalducci et al. (2020)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eDactylorhiza incarnata\\u003c/em\\u003e (L.) So\\u0026oacute;\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;2.63\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eNaczk et al. (2018)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eDactylorhiza maculata\\u003c/em\\u003e var. \\u003cem\\u003efuchsii\\u003c/em\\u003e (Druce) Hyl.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;5.06\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eColeoptera,\\u003c/p\\u003e\\n \\u003cp\\u003eDiptera\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGutowski (1990); Naczk et al. (2018)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eDactylorhiza maculata\\u003c/em\\u003e (L.) So\\u0026oacute; \\u003cem\\u003evar. maculata\\u003c/em\\u003e\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;4.82\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eNaczk et al. (2018); Koivisto, Valius \\u0026amp; Salonen (2002)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eDactylorhiza majalis\\u003c/em\\u003e (Rchb.) P.F.Hunt \\u0026amp; Summerh.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;3.63\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eDiptera, Coleoptera Hymenoptera\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eNaczk et al. (2018)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eDisa cooperi\\u003c/em\\u003e Rchb.f.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;0.89\\u0026thinsp;=\\u0026thinsp;sucrose rich\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eLepidoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Moths)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eJohnson (1995); Johnson (2006)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eElleanthus brasiliensis\\u003c/em\\u003e (Lindl.) Rchb.f.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;27.99\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eTrochilidae (Hummingbirds)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eNunes \\u003cem\\u003eet al.\\u003c/em\\u003e (2013)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eGymnadenia conopsea\\u003c/em\\u003e (L.) R.Br.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;4.2\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eLepidoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(Butterflies)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGijbels et al. (2014)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eHabenaria hieronymi\\u003c/em\\u003e Kraenzl.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;0.19\\u0026thinsp;=\\u0026thinsp;hexose rich\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGaletto et al. (1997)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eHabenaria gourlieana\\u003c/em\\u003e Gillies ex Lindl.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;5.9\\u0026ndash;22.26\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eLepidoptera (Hawkmoths)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGaletto et al. (1997)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eHabenaria obtusa\\u003c/em\\u003e Lindl. *\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;27.5\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eLepidoptera\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGottsberger et al. (1984)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eOR, Orch\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003ePelexia bonariensis\\u003c/em\\u003e (Lindl.) Schltr.\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;1.70\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(\\u003cem\\u003eBombus\\u003c/em\\u003e)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGaletto et al. (1997); Buzatto et al. (2022)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eVA, Vani\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eVanilla hartii\\u003c/em\\u003e Rolfe\\u003c/p\\u003e\\n \\u003cp\\u003er\\u0026thinsp;=\\u0026thinsp;5.64\\u0026thinsp;=\\u0026thinsp;sucrose dominant\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHymenoptera\\u003c/p\\u003e\\n \\u003cp\\u003e(\\u003cem\\u003eEuglossa\\u003c/em\\u003e)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eWatteyn et al. (2023)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cdiv\\u003e\\n \\u003ctable id=\\\"Tab2\\\" border=\\\"1\\\"\\u003e\\n \\u003ccaption language=\\\"En\\\"\\u003e\\n \\u003cdiv\\u003eTable 3\\u003c/div\\u003e\\n \\u003cdiv\\u003e\\n \\u003cp\\u003eComparative characteristics of the only two species of orchids known to produce hexose-rich nectar\\u003c/p\\u003e\\n \\u003c/div\\u003e\\n \\u003c/caption\\u003e\\n \\u003ccolgroup cols=\\\"4\\\"\\u003e\\u003c/colgroup\\u003e\\n \\u003cthead\\u003e\\n \\u003ctr\\u003e\\n \\u003cth align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eFunctional trait\\u003c/p\\u003e\\n \\u003c/th\\u003e\\n \\u003cth align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eP. innubum\\u003c/em\\u003e\\u003c/p\\u003e\\n \\u003c/th\\u003e\\n \\u003cth align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e\\u003cem\\u003eC. guayanense\\u003c/em\\u003e\\u003c/p\\u003e\\n \\u003c/th\\u003e\\n \\u003cth align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eComparison\\u003c/p\\u003e\\n \\u003c/th\\u003e\\n \\u003c/tr\\u003e\\n \\u003c/thead\\u003e\\n \\u003ctbody\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGeographic distribution\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eNarrow endemic\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eWidespread\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003edifferent\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHabit\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGeophyte\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGeophyte\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eequal\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHabitat\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eGrasslands and peatlands by streams\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eHighland grasslands, savannas and pastures\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003esimilar\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eFlowering populations\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eDense\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eDense\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003esimilar\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eFlowering plant size\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e30-90cm\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e9-40cm\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eoverlapping\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eFlowers per spike\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e6\\u0026ndash;20 flowers\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e(9\\u0026ndash;)30\\u0026ndash;120(\\u0026ndash;160)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eoverlapping\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eFlower colour\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003ePetals white or purplish\\u003c/p\\u003e\\n \\u003cp\\u003eLabellum white or pink\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003ePetals creamy white\\u003c/p\\u003e\\n \\u003cp\\u003eLabellum yellowish cream\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003esimilar\\u003c/p\\u003e\\n \\u003cp\\u003esimilar\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eFlower size\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e6-9mm across;\\u003c/p\\u003e\\n \\u003cp\\u003eLabellum 7\\u0026ndash;9 x 3-3.5mm\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003e4\\u0026ndash;6 across;\\u003c/p\\u003e\\n \\u003cp\\u003eLabellum 3.5\\u0026ndash;4.3 x 1.8-2.8mm\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eoverlapping\\u003c/p\\u003e\\n \\u003cp\\u003edifferent\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eFlower resupination\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eNot resupinate\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eResupinate\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003edifferent\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eVisitors observed with pollinaria\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eBees: Apidae, Halictidae, Wasps (1 species)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003eBees: Apidae, Halictidae\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd align=\\\"left\\\"\\u003e\\n \\u003cp\\u003esimilar\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003c/tbody\\u003e\\n \\u003c/table\\u003e\\n\\u003c/div\\u003e\\n\\u003cp\\u003eHexose-dominant nectar is rare in orchids (Table\\u0026nbsp;\\u003cspan\\u003e2\\u003c/span\\u003e), but is the same true outside of the orchids? To address this question, we segregated all the species with hexose-dominant nectars (but at least 1% sucrose) that were herbs, shrubs or subshrubs, and pollinated by either bees or generalists from the list of 1214 angiosperm with data on nectar sugars compiled by Chalcoff et al. (\\u003cspan\\u003e2017\\u003c/span\\u003e). This segregate list recorded 45 species in ten botanical families that were widely scattered across the angiosperm phylogenetic tree. We then investigated these 45 species in Plants of the World (POWO \\u003cspan\\u003e2024\\u003c/span\\u003e) and reliable identifications in the I-naturalist site and found that they followed a loose pattern (with some exceptions). White, cream, yellow or orange were the common colours, while pink, violet or purple were rare, and red was absent. Most of them had small, densely aggregated flowers, but there were some exceptions to this norm (e.g., \\u003cem\\u003eTecoma stans\\u003c/em\\u003e (L.) Juss. ex Kunth). Virtually all were temperate or subtropical plants, although the plants listed by Chalcoff et al. (\\u003cspan\\u003e2017\\u003c/span\\u003e) were mostly tropical. In a semi-desertic, frost-prone scrubland in Patagonia, presumably pollinator hostile, most plants had hexose-dominant nectars and were bee-pollinated (Bernardello et al. \\u003cspan\\u003e1999\\u003c/span\\u003e). We propose the term \\u0026lsquo;modest\\u0026rsquo; pollination syndrome be applied to orchids that are: geophytic, have small, pale flowers (probably below 1 cm), offer imperceptible quantities of hexose-dominant nectar on an exposed labellum and attract a wide range of insect visitors.\\u003c/p\\u003e\\n\\u003cdiv\\u003e\\n \\u003cbr\\u003e\\n\\u003c/div\\u003e\\n\\u003cp\\u003eConsidering the high species richness of the Orchidaceae, nectar records are surprisingly few (Brzosko et al. \\u003cspan\\u003e2021\\u003c/span\\u003e). Sucrose-dominant nectar predominates both in the angiosperms (56.8% of 1214 species; Chalcoff et al. \\u003cspan\\u003e2017\\u003c/span\\u003e) and in the Orchidaceae (80.5% of 43 species; Brzosko and Mirski \\u003cspan\\u003e2021\\u003c/span\\u003e). Pollinator group was statistically confirmed in both studies as the main ecological driver, followed by climate, i.e., latitudinal climatic zone (for the angiosperms) or climate type (for the orchids).\\u003c/p\\u003e\\n\\u003cp\\u003eBaker and Baker (\\u003cspan\\u003e1983\\u003c/span\\u003e), studying nectar composition in 765 species of angiosperms, found that 44% of species pollinated by short-tongued bees produced hexose-dominant nectar, while only 6% of species pollinated by long-tongued bees had this type of nectar. Wilmer (\\u003cspan\\u003e2011\\u003c/span\\u003e) has argued that sucrose/hexose ratios may have more to do with maintaining optimum nectar concentration and viscosity than pollinator preference. Pure sucrose nectar dries out faster than pure hexose nectar at the same humidity levels (Corbet et al. \\u003cspan\\u003e1979\\u003c/span\\u003e). Therefore, hexose-rich nectar might be preferentially produced by exposed nectaries (pollinated by short-tongued insects), and sucrose-rich nectar by deep, hidden nectaries (pollinated by long-tongued insects). However, Brzosko and Mirski (\\u003cspan\\u003e2021\\u003c/span\\u003e) found no statistical differences of sugar composition between orchids that offer spur nectar and open nectar, although these authors noted that generalist species were under-represented in the available data. It is possible that when nectar is produced not only by exposed nectaries, but in minute quantities in plants that form dense populations (such as was recorded in \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e and \\u003cem\\u003ePrasophyllum innubum\\u003c/em\\u003e), natural selection will favour high-hexose nectar that is more resistant to desiccation. It is worth mentioning in this context that \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e flowers in early wet season when mean daily humidity is very high and is also a generalistic species, with a wider taxonomic range of bee pollinators than any other species in either the \\u003cem\\u003ePelexia\\u003c/em\\u003e or the \\u003cem\\u003eCyclopogon\\u003c/em\\u003e clades \\u003cem\\u003esensu\\u003c/em\\u003e Salazar et al. (\\u003cspan\\u003e2018\\u003c/span\\u003e) with known pollinators (Supporting information, Table S2).\\u003c/p\\u003e\\n\\u003cp\\u003eThe glandular trichomes that abound on \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e inflorescences and outer surfaces of the flowers are lipid secreting (Fig.\\u0026nbsp;\\u003cspan\\u003e4\\u003c/span\\u003eL); these lipids may be acting as aromatic attractants as recorded in \\u003cem\\u003eC. elatus\\u003c/em\\u003e (Sw.) Schltr., by Wiemer et al. (\\u003cspan\\u003e2009\\u003c/span\\u003e) or as rewards for oil-collecting or scent-collecting bees. \\u003cem\\u003ePachygonium pteryganthum\\u003c/em\\u003e (Rchb. f. \\u0026amp; Warm.) Schltr., a member of the \\u003cem\\u003ePelexia\\u003c/em\\u003e clade, is pollinated by oil-collecting female \\u003cem\\u003eCentris\\u003c/em\\u003e (\\u003cem\\u003eMelacentris\\u003c/em\\u003e) bees (Buzatto et al. \\u003cspan\\u003e2022\\u003c/span\\u003e). In our study area, male \\u003cem\\u003eTetrapedia\\u003c/em\\u003e bees are known to collect oil from Malpighiaceae flowers (Cappellari et al. \\u003cspan\\u003e2012\\u003c/span\\u003e) and we observed a male \\u003cem\\u003eTetrapedia\\u003c/em\\u003e bee visiting the flowers of \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e, but no such oil-collecting activity was observed. The \\u003cem\\u003eTetrapedia\\u003c/em\\u003e bee was foraging for nectar, and is presumed to be a pollinator, as it gathered three pollinaria during visits, which it subsequently tried to remove with front legs. Volatile chemicals (scent) can also be collected for mating purposes by male Neotropical orchid bees, i.e. Euglossini (Carvalho-Filho 2010). Despite the high density of glandular trichomes on the \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e inflorescences, there was no evidence of this kind of reward collecting by pollinators in our study; Euglossini visitors were not observed in the field and glandular trichomes were intact, not destroyed by visitors, with the cuticle on the heads undamaged (Fig.\\u0026nbsp;\\u003cspan\\u003e4\\u003c/span\\u003eG, J\\u0026ndash;L).\\u003c/p\\u003e\\n\\u003cp\\u003eA sweet scent was reported in the flowers of \\u003cem\\u003eCyclopogon congestus\\u003c/em\\u003e (Vell.) Hoehne (Singer and Sazima \\u003cspan\\u003e1999\\u003c/span\\u003e), \\u003cem\\u003eC. diversifoIius\\u003c/em\\u003e (Cogn.) Schltr. (=\\u0026thinsp;\\u003cem\\u003eC. apricus\\u003c/em\\u003e (Lindl.) Schltr.) (Singer and Cocucci \\u003cspan\\u003e1999\\u003c/span\\u003e), \\u003cem\\u003eC. elatus\\u003c/em\\u003e (Wiemer et al. \\u003cspan\\u003e2009\\u003c/span\\u003e) and \\u003cem\\u003eVeyretia hassleri\\u003c/em\\u003e (Cogn.) Szlach. (Supporting Information, Table S2). In \\u003cem\\u003eC. congestus\\u003c/em\\u003e, however, the scent, which was perceived from the morning to the evening hours, was produced by apical callosities on the inner surface of the labellum and lateral sepals (Singer and Sazima \\u003cspan\\u003e1999\\u003c/span\\u003e), and is thus not analogous to the multicellular, glandular trichomes observed on the outer surface of the corolla in \\u003cem\\u003eC. guayanensis.\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eIn \\u003cem\\u003eCyclopogon elatus\\u003c/em\\u003e, osmophores are reported as trichomes on the outer surface of the labellum (Wiemer et al. \\u003cspan\\u003e2009\\u003c/span\\u003e) such as was recorded by us in \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e. However, in \\u003cem\\u003eC. elatus\\u003c/em\\u003e these trichomes are unicellular, while in \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e they are pluricellular, with stalk and head, but also occur on the outer surface of the labellum (as well as on other inflorescence surfaces). Also, in \\u003cem\\u003eC. elatus\\u003c/em\\u003e, only the osmophores of open flowers release scent, which is absent in buds and withered flowers (Wiemer et al. \\u003cspan\\u003e2009\\u003c/span\\u003e). Thus, \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e also differs from \\u003cem\\u003eC. elatus\\u003c/em\\u003e in this aspect, since secretion appears to persist in senescent flowers (Fig.\\u0026nbsp;\\u003cspan\\u003e4\\u003c/span\\u003eD).\\u003c/p\\u003e\\n\\u003cp\\u003eThe combined evidence suggests that the glandular trichomes on the inflorescence and outer surface of the flowers of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e are probably osmophores. However, the scent detected in \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e was extremely faint and was in fact only perceived by one of us; therefore, the function and composition of the lipids secreted by these trichomes should be the subject of further investigation. The external position on the flower is unusual for osmophores; the inner surface of the labellum is the most widespread scent-releasing surface in orchids (Wiemer et al. \\u003cspan\\u003e2009\\u003c/span\\u003e). In fact, very few angiosperms have osmophores on the outer surface of the flowers, as seems to be the case in \\u003cem\\u003eCyclopogon\\u003c/em\\u003e; it was also reported in \\u003cem\\u003eCotylolabium lutzii\\u003c/em\\u003e (Pabst) Garay, another genus of the Spiranthinae that is sister taxon to the rest of the Subtribe (Borba et al. \\u003cspan\\u003e2014\\u003c/span\\u003e). Perhaps the presence of osmophores on the outer surface of the flowers is a common characteristic of this subtribe; this hypothesis would require further investigation.\\u003c/p\\u003e\\n\\u003cp\\u003eThe cuticle allows both scent diffusion in osmophores and secretion releasing in nectaries; the cuticle expands and there is secretion accumulation in the periplasmic space; this phase was clearly recorded in the nectariferous papillae of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e in our study (Fig.\\u0026nbsp;\\u003cspan\\u003e4\\u003c/span\\u003eM\\u0026ndash;N, arrows). In the secretory labellum tissue of \\u003cem\\u003eEpipactis atropurpurea\\u003c/em\\u003e, the nectar is released by disruption of the epidermal cell cuticle in the secretory stage (Pais and Figueiredo \\u003cspan\\u003e1994\\u003c/span\\u003e). In the nectariferous papillae of cotton (\\u003cem\\u003eGossypium hirsutum\\u003c/em\\u003e L., Malvaceae), however, a two-layered cuticle is detached from the wall in the secretory papillae and the nectar crosses this structure (Eleftheriou and Hall \\u003cspan\\u003e1983\\u003c/span\\u003e); further studies are needed to clarify the nectar releasing mechanism in \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e.\\u003c/p\\u003e\\n\\u003cp\\u003eRaphid-rich idioblasts have been presumed to be herbivore deterrents (Molano-Flores \\u003cspan\\u003e2001\\u003c/span\\u003e). Raphid containing idioblasts are not widespread in dicotyledons (Cutler et al. \\u003cspan\\u003e2008\\u003c/span\\u003e) but are found in many monocotyledons (Fahn \\u003cspan\\u003e1988\\u003c/span\\u003e) and were observed in the bracteoles (Fig.\\u0026nbsp;\\u003cspan\\u003e4\\u003c/span\\u003eF\\u0026ndash;G), sepals and petals (Fig.\\u0026nbsp;\\u003cspan\\u003e4\\u003c/span\\u003eH) of \\u003cem\\u003eCyclopogon guayanensis\\u003c/em\\u003e. Raphid-rich idioblasts occur in several species of orchids, both in subfamilies Orchidoideae and Epidendroideae. In the Orchidoideae, they are found in the floral parts of \\u003cem\\u003eHabenaria gourlieana\\u003c/em\\u003e Gillies ex Lindl. (Galetto et al. \\u003cspan\\u003e1997\\u003c/span\\u003e), and in the hypochilum of \\u003cem\\u003eCotylolabium lutzii\\u003c/em\\u003e (Borba et al. \\u003cspan\\u003e2014\\u003c/span\\u003e) \\u0026ndash; also a member of subtribe Spiranthinae and were noted to be common in this subtribe by Adachi (\\u003cspan\\u003e2015\\u003c/span\\u003e), based on studies of floral anatomy of \\u003cem\\u003eCyclopogon apricus\\u003c/em\\u003e, \\u003cem\\u003eMesadenella cuspidata\\u003c/em\\u003e (Lindl.) Garay, \\u003cem\\u003eSarcoglottis fasciculata\\u003c/em\\u003e, and \\u003cem\\u003eSauroglossum elatum.\\u003c/em\\u003e In subfamily Epidendroideade, they occur in the ghost orchid, \\u003cem\\u003eEpipogium aphyllum\\u003c/em\\u003e (Swięczkowska and Kowalkowska \\u003cspan\\u003e2015\\u003c/span\\u003e). However, the density of idioblasts is noticeably higher in the sepals and petals of \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e (Fig.\\u0026nbsp;\\u003cspan\\u003e4\\u003c/span\\u003eH, arrowheads) than in most of these orchids. In many orchids of the subtribe Pleurothallidinae, prismatic crystals occur as idioblasts in the floral parts and have been associated to visual attraction of pollinators (Bogar\\u0026iacute;n et al. \\u003cspan\\u003e2018\\u003c/span\\u003e), but herbivore dissuasion is another possible role.\\u003c/p\\u003e\\n\\u003cp\\u003eThe fact that herbaceous or shrubby plants with hexose-dominant nectar and generalistic pollination systems are usually confined to temperate or subtropical environments (Chalcoff et al. \\u003cspan\\u003e2017\\u003c/span\\u003e) but appeared in a tropical savanna grassland species is interesting. In the highly seasonal Cerrado biome where our study was carried out, 90% of annual precipitation occurs between the months of October and April, followed by a dry season lasting between 4 and 7 months (Bustamente et al. 2012); in the Distrito Federal, c. 50% of annual precipitation occurs between December and February (Anuncia\\u0026ccedil;\\u0026atilde;o et al. \\u003cspan\\u003e2014\\u003c/span\\u003e). We tentatively suggest that a short favourable reproductive season is the driver behind this suite of characters. Its similarity to \\u003cem\\u003eEpipogium aphyllum\\u003c/em\\u003e suggests convergence with these orchids (Swiwczkowska and Kowalkowska 2015).\\u003c/p\\u003e\\n\\u003cp\\u003eOur theory for the unusual characteristics of \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e is that, as a therophytic orchid that inhabits fire-prone, highly seasonal savanna grasslands, it will presumably be under two selective forces: 1) lack of competition, since grasslands are potentially resource-poor landscapes for pollinating insects and will tend to have low pollinator density, therefore favouring a \\u0026ldquo;take what you can get\\u0026rdquo; generalist pollination strategy offering scanty rewards; 2) a limited growing and flowering season (during the short wet season) which would put a premium on economy of energy, i.e., favour small plants with small flowers, small fruits, and minimalistic pollinator rewards.\\u003c/p\\u003e\\n\\u003cp\\u003eThe floral biology (position of the viscidium and pollinator behaviour) and micromorphological data gathered in this study (external glandular hairs, raphid-rich idioblasts, internal nectariferous papillae) support the transfer of \\u003cem\\u003eBrachystele guayanensis\\u003c/em\\u003e to \\u003cem\\u003eCyclopogon\\u003c/em\\u003e (Meneguzzo et al. \\u003cspan\\u003e2024\\u003c/span\\u003e). Our hypothesis is that the \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e \\u0026ndash; \\u003cem\\u003eVeyretia\\u003c/em\\u003e clade is a lineage within \\u003cem\\u003eCyclopogon\\u003c/em\\u003e (a predominantly forest genus well adapted to pollination by halictid bees) that has moved into open habitats with accompanying pollinator shifts (i.e., from Halictidae to Apidae and possibly from Halictidae to Megachilidae, respectively; see Table S2), although this would need further investigation of the floral biology of \\u003cem\\u003eVeyretia\\u003c/em\\u003e. Studies of species of \\u003cem\\u003eBrachystele s.s.\\u003c/em\\u003e would obviously also be desirable to confirm parallel evolution.\\u003c/p\\u003e\\n\\u003cp\\u003eTo conclude, on a more general note, we would suggest further testing for trace nectar in orchids that apparently offer no rewards. We cite \\u003cem\\u003everbatim\\u003c/em\\u003e a paragraph from the study by Shrestha et al. (\\u003cspan\\u003e2020\\u003c/span\\u003e: 5) on rewardlessness in orchids that reflects our beliefs: \\u003cem\\u003eIf neural mechanisms of reward detection can be exploited and are widespread among floral visitors, the use of such stingy rewards by orchids lacking visible nectar might also be widespread. Pollinator manipulation by trace rewards might still be considered largely deceitful, but the nature of the deceit would be more complex and more subtle than in the case of complete absence of floral sugars. A paucity of reward may actually encourage appropriate flower-handling by visitors.\\u003c/em\\u003e\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003eACKNOWLEDGEMENTS\\u003c/p\\u003e\\n\\u003cp\\u003eWe thank Prof. Rodrigo Barbosa Gon\\u0026ccedil;alves (Universidade Federal do Paran\\u0026aacute;) for identifying or confirming the identification of several of the bees. \\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003cstrong\\u003eFunding\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eFAPERJ (\\u003cem\\u003eFunda\\u0026ccedil;\\u0026atilde;o de Amparo \\u0026agrave; Pesquisa do Rio de Janeiro\\u003c/em\\u003e) funded a post-doctoral grant and financial support (grants n. E-26/206.092/2022 and E-26/206.093/2022) to TECM. CNPq (\\u003cem\\u003eConselho Nacional de Desenvolvimento Cient\\u0026iacute;fico e Tecnol\\u0026oacute;gico\\u003c/em\\u003e, Brazil) funded PQ2 \\u003cem\\u003eProdutividade em Pesquisa\\u003c/em\\u003e research grants to CEBP and JANB.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eCompeting interests\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors declare no competing interests.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAuthor contributions\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eTECM and CEBP conceived the project and designed the experiments. CEBP, AJCA and ACM did the field work, produced images and videos, and incorporated voucher specimens of plants and insects into scientific collections. ACM and AJCA identified the insects. SMG did the anatomical and histochemical analysis. TCRW analyzed the nectar sugars. CEBP wrote the manuscript with significant contributions from TECM, JANB, and SMG. All authors contributed to revisions and accepted the final version of this manuscript.\\u003c/p\\u003e\\u003cp\\u003e\\u003cstrong\\u003eSupporting information\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAdditional supporting information may be found online in the Supporting Information section at the end of the article. Tables S1 and S2.\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n\\u003cli\\u003eAdachi SA (2015) Estrutura floral de representantes da tribo Cranichideae (Orchidoideae: Orchidaceae). Universidade Estadual Paulista \\u0026ldquo;J\\u0026uacute;lio de Mesquita Filho\\u0026rdquo;\\u003c/li\\u003e\\n\\u003cli\\u003eAnuncia\\u0026ccedil;\\u0026atilde;o YMT da, Walde DHG, Rocha RP da (2014) Observed summer weather regimes and associated extreme precipitation over Distrito Federal, west-central Brazil. Environ Earth Sci 72:4835\\u0026ndash;4848. https://doi.org/10.1007/s12665-014-3607-9\\u003c/li\\u003e\\n\\u003cli\\u003eBaker HG, Baker I (1983) Floral nectar sugars constituents in relation to pollinator type. In: Jones CE, Little RJ (eds) Handbook of experimental pollination biology. Van Nostrand Reinhold, New York, pp 117\\u0026ndash;141\\u003c/li\\u003e\\n\\u003cli\\u003eBalducci MG, van der Niet T, Johnson SD (2019) Butterfly pollination of \\u003cem\\u003eBonatea cassidea\\u003c/em\\u003e (Orchidaceae): Solving a puzzle from the Darwin era. South African J Bot 123:308\\u0026ndash;316. https://doi.org/10.1016/j.sajb.2019.03.030\\u003c/li\\u003e\\n\\u003cli\\u003eBalducci MG, Van Der Niet T, Johnson SD (2020) Diel scent and nectar rhythms of an African orchid in relation to bimodal activity patterns of hawkmoth pollinators. Ann Bot 126:1155\\u0026ndash;1164. https://doi.org/10.1093/aob/mcaa132\\u003c/li\\u003e\\n\\u003cli\\u003eBell AK, Roberts DL, Hawkins JA, et al (2009) Comparative micromorphology of nectariferous and nectarless labellar spurs in selected clades of subtribe Orchidinae (Orchidaceae). Bot J Linn Soc 160:369\\u0026ndash;387. https://doi.org/10.1111/j.1095-8339.2009.00985.x\\u003c/li\\u003e\\n\\u003cli\\u003eBenitez-Vieyra S, Medina AM, Glinos E, Cocucci AA (2006) Pollinator-mediated selection on floral traits and size of floral display in \\u003cem\\u003eCyclopogon elatus\\u003c/em\\u003e, a sweat bee-pollinated orchid. Funct Ecol 20:948\\u0026ndash;957. https://doi.org/10.1111/j.1365-2435.2006.01179.x\\u003c/li\\u003e\\n\\u003cli\\u003eBernardello G, Galetto L, Forcone A (1999) Floral nectar chemical composition of some species from Patagonia. II. Biochem Syst Ecol 27:779\\u0026ndash;790. https://doi.org/10.1016/S0305-1978(99)00029-0\\u003c/li\\u003e\\n\\u003cli\\u003eBogar\\u0026iacute;n D, Fern\\u0026aacute;ndez M, Borkent A, et al (2018) Pollination of \\u003cem\\u003eTrichosalpinx\\u003c/em\\u003e (Orchidaceae: Pleurothallidinae) by biting midges (Diptera: Ceratopogonidae). Bot J Linn Soc 186:510\\u0026ndash;543. https://doi.org/10.1093/botlinnean/box087\\u003c/li\\u003e\\n\\u003cli\\u003eBorba EL, Salazar GA, Mazzoni-Viveiros S, Batista JAN (2014) Phylogenetic position and floral morphology of the Brazilian endemic, monospecific genus \\u003cem\\u003eCotylolabium\\u003c/em\\u003e: A sister group for the remaining Spiranthinae (Orchidaceae). Bot J Linn Soc 175:29\\u0026ndash;46. https://doi.org/10.1111/boj.12136\\u003c/li\\u003e\\n\\u003cli\\u003eBrzosko E, Bajguz A, Burzyńska J, Chmur M (2023) Does Reproductive Success in Natural and Anthropogenic Populations of Generalist \\u003cem\\u003eEpipactis helleborine\\u003c/em\\u003e Depend on Flower Morphology and Nectar Composition? Int J Mol Sci 24:4276. https://doi.org/10.3390/ijms24054276\\u003c/li\\u003e\\n\\u003cli\\u003eBrzosko E, Bajguz A, Chmur M, et al (2021) How are the flower structure and nectar composition of the generalistic orchid \\u003cem\\u003eNeottia ovata\\u003c/em\\u003e adapted to a wide range of pollinators? Int J Mol Sci 22:1\\u0026ndash;27. https://doi.org/10.3390/ijms22042214\\u003c/li\\u003e\\n\\u003cli\\u003eBrzosko E, Mirski P (2021) Floral nectar chemistry in orchids: A short review and meta-analysis. Plants 10:2315. https://doi.org/10.3390/plants10112315\\u003c/li\\u003e\\n\\u003cli\\u003eBustamante MMC, Nardoto GB, Pinto AS, et al (2012) Potential impacts of climate change on biogeochemical functioning of Cerrado ecosystems. Brazilian J Biol 72:655\\u0026ndash;671\\u003c/li\\u003e\\n\\u003cli\\u003eBuzatto CR (2014) Estudos taxon\\u0026ocirc;micos, filogen\\u0026eacute;ticos e biossistem\\u0026aacute;ticos em orqu\\u0026iacute;deas terrestres (Orchidaceae: Orchidoideae) brasileiras. Universidade Federal do Rio Grande Sul\\u003c/li\\u003e\\n\\u003cli\\u003eBuzatto CR, Nervo MH, Sanguinetti A, et al (2022) Efficient pollination and high reproductive success in two Brazilian Spiranthinae orchids: Insights on the evolutionary history of pollination within the Pelexia clade. Plant Species Biol 37:182\\u0026ndash;196. https://doi.org/10.1111/1442-1984.12366\\u003c/li\\u003e\\n\\u003cli\\u003eCappellari SC, Melo GAR, Aguiar AJC, Neff JL (2012) Floral oil collection by male \\u003cem\\u003eTetrapedia \\u003c/em\\u003ebees (Hymenoptera: Apidae: Tetrapediini. Apidologie 43:39\\u0026ndash;50. https://doi.org/10.1007/s13592-011-0072-2\\u003c/li\\u003e\\n\\u003cli\\u003eCarvalho Filho F da S (2010) Scent-robbing and fighting among male orchid bees, \\u003cem\\u003eEulaema\\u003c/em\\u003e (\\u003cem\\u003eApeulaema\\u003c/em\\u003e) \\u003cem\\u003enigrita\\u003c/em\\u003e Lepeletier, 1841 (Hymenoptera: Apidae: Euglossini). Biota Neotrop 10:405\\u0026ndash;408. https://doi.org/10.1590/s1676-06032010000200038\\u003c/li\\u003e\\n\\u003cli\\u003eChalcoff VR, Gleiser G, Ezcurra C, Aizen MA (2017) Pollinator type and secondarily climate are related to nectar sugar composition across the angiosperms. Evol Ecol 31:585\\u0026ndash;602. https://doi.org/10.1007/s10682-017-9887-2\\u003c/li\\u003e\\n\\u003cli\\u003eChase MW, Cameron KM, Freudenstein J V., et al (2015) An updated classification of Orchidaceae. Bot J Linn Soc 177:151\\u0026ndash;174. https://doi.org/10.1111/boj.12234\\u003c/li\\u003e\\n\\u003cli\\u003eCorbet SA, Unwin DM, Prys‐Jones OE (1979) Humidity, nectar and insect visits to flowers, with special reference to \\u003cem\\u003eCrataegus\\u003c/em\\u003e, \\u003cem\\u003eTilia\\u003c/em\\u003e and \\u003cem\\u003eEchium\\u003c/em\\u003e. Ecol Entomol 4:9\\u0026ndash;22. https://doi.org/10.1111/j.1365-2311.1979.tb00557.x\\u003c/li\\u003e\\n\\u003cli\\u003eCutler DF, Botha T, Stevenson DW (2008) Plant anatomy: An applied approach. Blackwell Publishing Ltd, Malden, Massachusetts, USA\\u003c/li\\u003e\\n\\u003cli\\u003eDavies KL, Stpiczyńska M, Gregg A (2005) Nectar-secreting floral stomata in \\u003cem\\u003eMaxillaria anceps\\u003c/em\\u003e Ames \\u0026amp; C. Schweinf. (Orchidaceae). Ann Bot 96:217\\u0026ndash;227. https://doi.org/10.1093/aob/mci182\\u003c/li\\u003e\\n\\u003cli\\u003eEleftheriou EP, Hall JL (1983) The extrafloral nectaries of cotton: I. Fine structure of the secretory papillae. J Exp Bot 34:103\\u0026ndash;119. https://doi.org/10.1093/jxb/34.2.103\\u003c/li\\u003e\\n\\u003cli\\u003eFahn A (1989) Plant anatomy. Pergamon Press, Oxford\\u003c/li\\u003e\\n\\u003cli\\u003eFahn A (1988) Secretory tissues in vascular plants. New Phytol 108:229\\u0026ndash;257. https://doi.org/10.1111/j.1469-8137.1988.tb04159.x\\u003c/li\\u003e\\n\\u003cli\\u003eForcone A, Galetto L, Bernardello L (1997) Floral nectar chemical composition of some species from Patagonia. Biochem Syst Ecol 25:395\\u0026ndash;402. https://doi.org/10.1016/S0305-1978(97)00030-6\\u003c/li\\u003e\\n\\u003cli\\u003eFreeman CE, Worthington RD, Jackson MS (1991) Floral Nectar Sugar Compositions of Some South and Southeast Asian Species. Biotropica 23:568. https://doi.org/10.2307/2388394\\u003c/li\\u003e\\n\\u003cli\\u003eGaletto L (1995) Estructura del nectario y composici\\u0026oacute;n posici\\u0026oacute;n qu\\u0026iacute;mica del n\\u0026eacute;ctar en cuatro especies de Scrophulariaceae. Kurtziana 24:105\\u0026ndash;118\\u003c/li\\u003e\\n\\u003cli\\u003eGaletto L, Bernardello G (2003) Nectar sugar composition in angiosperms from Chaco and Patagonia (Argentina): An animal visitor\\u0026rsquo;s matter? Plant Syst Evol 238:69\\u0026ndash;86. https://doi.org/10.1007/s00606-002-0269-y\\u003c/li\\u003e\\n\\u003cli\\u003eGaletto L, Bernardello G, Rivera GL (1997) Nectar, nectaries, flower visitors, and breeding system in five terrestrial Orchidaceae from central Argentina. J Plant Res 110:393\\u0026ndash;403. https://doi.org/10.1007/bf02506798\\u003c/li\\u003e\\n\\u003cli\\u003eGijbels P, Van den Ende W, Honnay O (2014) Landscape scale variation in nectar amino acid and sugar composition in a Lepidoptera pollinated orchid species and its relation with fruit set. J Ecol 102:136\\u0026ndash;144. https://doi.org/10.1111/1365-2745.12183\\u003c/li\\u003e\\n\\u003cli\\u003eGottsberger G, Schrauwen J, Linskens HF (1984) Amino acids and sugars in nectar, and their putative evolutionary significance. Plant Syst Evol 145:55\\u0026ndash;77. https://doi.org/10.1007/BF00984031\\u003c/li\\u003e\\n\\u003cli\\u003eGutowski JM (1990) Pollination of the orchid \\u003cem\\u003eDactylorhiza fuchsii\\u003c/em\\u003e by longhorn beetles in primeval forests of Northeastern Poland. Biol Conserv 51:287\\u0026ndash;297. https://doi.org/10.1016/0006-3207(90)90114-5\\u003c/li\\u003e\\n\\u003cli\\u003eJia LB, Huang SQ (2022) An examination of nectar production in 34 species of \\u003cem\\u003eDendrobium \\u003c/em\\u003eindicates that deceptive pollination in the orchids is not popular. J Syst Evol 60:1371\\u0026ndash;1377. https://doi.org/10.1111/jse.12799\\u003c/li\\u003e\\n\\u003cli\\u003eJohnson SD (1995) Observations of hawkmoth pollination in the South African orchid \\u003cem\\u003eDisa cooperi\\u003c/em\\u003e. Nord J Bot 15:121\\u0026ndash;125. https://doi.org/10.1111/j.1756-1051.1995.tb00128.x\\u003c/li\\u003e\\n\\u003cli\\u003eJ\\u0026uuml;rgens A, Bosch SR, Webber AC, et al (2009) Pollination biology of \\u003cem\\u003eEulophia alta (\\u003c/em\\u003eOrchidaceae) in Amazonia: Effects of pollinator composition on reproductive success in different populations. Ann Bot 104:897\\u0026ndash;912. https://doi.org/10.1093/aob/mcp191\\u003c/li\\u003e\\n\\u003cli\\u003eK\\u0026auml;pyl\\u0026auml; M (1978) Amount and type of nectar sugar in some wild flowers in Finland. Ann Bot Fenn 15:85\\u0026ndash;88\\u003c/li\\u003e\\n\\u003cli\\u003eKoivisto AM, Vallius E, Salonen V (2002) Pollination and reproductive success of two colour variants of a deceptive orchid, \\u003cem\\u003eDactylorhiza maculata\\u003c/em\\u003e (Orchidaceae). Nord J Bot 22:53\\u0026ndash;58. https://doi.org/10.1111/j.1756-1051.2002.tb01621.x\\u003c/li\\u003e\\n\\u003cli\\u003eLipińska MM, Archila FL, Haliński ŁP, et al (2022) Ornithophily in the subtribe Maxillariinae (Orchidaceae) proven with a case study of \\u003cem\\u003eOrnithidium fulgens\\u003c/em\\u003e in Guatemala. Sci Rep 12:5273. https://doi.org/10.1038/s41598-022-09146-4\\u003c/li\\u003e\\n\\u003cli\\u003eLuyt R, Johnson SD (2001) Hawkmoth pollination of the African epiphytic orchid \\u003cem\\u003eMystacidium venosum\\u003c/em\\u003e, with special reference to flower and pollen longevity. Plant Syst Evol 228:49\\u0026ndash;62\\u003c/li\\u003e\\n\\u003cli\\u003eLuyt RP (2002) Pollination and Evolution of the genus \\u003cem\\u003eMystacidium \\u003c/em\\u003e(Orchidaceae). University of Natal, South Africa\\u003c/li\\u003e\\n\\u003cli\\u003eMeneguzzo TEC, Carvalho BM, Batista JAN, et al (2024) \\u003cem\\u003eBrachystele guayanensis\\u003c/em\\u003e is a \\u003cem\\u003eCyclopogon \\u003c/em\\u003e(Orchidaceae): notes on its biology and taxonomy. Phytotaxa 658:109\\u0026ndash;119. https://doi.org/10.11646/phytotaxa.658.1.5\\u003c/li\\u003e\\n\\u003cli\\u003eMolano-Flores B (2001) Herbivory and calcium concentrations affect calcium oxalate crystal formation in leaves of \\u003cem\\u003eSida\\u003c/em\\u003e (Malvaceae). Ann Bot 88:387\\u0026ndash;391. https://doi.org/10.1006/anbo.2001.1492\\u003c/li\\u003e\\n\\u003cli\\u003eMorrant DS, Schumann R, Petit S (2009) Field methods for sampling and storing nectar from flowers with low nectar volumes. Ann Bot 103:533\\u0026ndash;542. https://doi.org/10.1093/aob/mcn241\\u003c/li\\u003e\\n\\u003cli\\u003eNaczk AM, Kowalkowska AK, Wisniewska N, et al (2018) Floral anatomy, ultrastructure and chemical analysis in \\u003cem\\u003eDactylorhiza incarnata\\u003c/em\\u003e/\\u003cem\\u003emaculata\\u003c/em\\u003e complex (Orchidaceae). Bot J Linn Soc 187:512\\u0026ndash;536. https://doi.org/10.1093/botlinnean/boy027\\u003c/li\\u003e\\n\\u003cli\\u003ePais MS, Figueiredo ACS (1994) Floral nectaries from \\u003cem\\u003eLimodorum abortivum\\u003c/em\\u003e (L.) Sw and \\u003cem\\u003eEpipactis atropurpurea\\u003c/em\\u003e Rafin (Orchidaceae): Ultrastructural changes in plastids during the secretory process. Apidologie 25:615\\u0026ndash;626. https://doi.org/10.1051/apido:19940612\\u003c/li\\u003e\\n\\u003cli\\u003ePais MSS, Neves HJC das (1980) Sugar Content of the Nectary Exudate of \\u003cem\\u003eEpipactis atropurpurea\\u003c/em\\u003e Rafin. Apidologie 11:39\\u0026ndash;45. https://doi.org/10.1051/apido:19800105\\u003c/li\\u003e\\n\\u003cli\\u003ePercival MS (1961) Types of Nectar in Angiosperms. New Phytol 60:235\\u0026ndash;281. https://doi.org/10.1111/j.1469-8137.1961.tb06255.x\\u003c/li\\u003e\\n\\u003cli\\u003ePetanidou T, Van Laere A, N. Ellis W, Smets E (2006) What shapes amino acid and sugar composition in Mediterranean floral nectars? Oikos 115:155\\u0026ndash;169. https://doi.org/10.1111/j.2006.0030-1299.14487.x\\u003c/li\\u003e\\n\\u003cli\\u003ePeter CI, Johnson SD (2009) Reproductive biology of \\u003cem\\u003eAcrolophia cochlearis\\u003c/em\\u003e (Orchidaceae): Estimating rates of cross-pollination in epidendroid orchids. Ann Bot 104:573\\u0026ndash;581. https://doi.org/10.1093/aob/mcn218\\u003c/li\\u003e\\n\\u003cli\\u003ePhillips RD, Bohman B, Brown GR, et al (2020) A specialised pollination system using nectar-seeking thynnine wasps in \\u003cem\\u003eCaladenia nobilis\\u003c/em\\u003e (Orchidaceae). Plant Biol 22:157\\u0026ndash;166. https://doi.org/10.1111/plb.13069\\u003c/li\\u003e\\n\\u003cli\\u003ePhillips RD, Bohman B, Peakall R, Reiter N (2024) Sexual attraction with pollination during feeding behaviour: implications for transitions between specialized strategies. Ann Bot 133:273\\u0026ndash;286. https://doi.org/10.1093/aob/mcad178\\u003c/li\\u003e\\n\\u003cli\\u003ePonert J, Tr\\u0026aacute;vn\\u0026iacute;ček P, Vuong TB, et al (2016) A new species of \\u003cem\\u003eCleisostoma \\u003c/em\\u003e(Orchidaceae) from the Hon Ba Nature Reserve in Vietnam: A multidisciplinary assessment. PLoS One 11:. https://doi.org/10.1371/journal.pone.0150631\\u003c/li\\u003e\\n\\u003cli\\u003ePOWO (2024) Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. In: Http://Www.Plantsoftheworldonline.Org/. http://www.plantsoftheworldonline.org/. Accessed 1 Apr 2024\\u003c/li\\u003e\\n\\u003cli\\u003eReiter N, Bohman B, Freestone M, et al (2019) Pollination by nectar-foraging thynnine wasps in the endangered \\u003cem\\u003eCaladenia arenaria\\u003c/em\\u003e and \\u003cem\\u003eCaladenia concolor\\u003c/em\\u003e (Orchidaceae). Aust J Bot 67:490\\u0026ndash;500. https://doi.org/10.1071/BT19033\\u003c/li\\u003e\\n\\u003cli\\u003eReiter N, Wicks M, Pollard G, et al (2023) Improving conservation and translocation success of an endangered orchid, \\u003cem\\u003eCaladenia xanthochila\\u003c/em\\u003e (Orchidaceae), through understanding pollination. Plant Ecol 224:715\\u0026ndash;727. https://doi.org/10.1007/s11258-023-01334-0\\u003c/li\\u003e\\n\\u003cli\\u003eSalazar GA, Batista JAN, Cabrera LI, et al (2018) Phylogenetic systematics of subtribe Spiranthinae (Orchidaceae: Orchidoideae: Cranichideae) based on nuclear and plastid DNA sequences of a nearly complete generic sample. Bot J Linn Soc 186:273\\u0026ndash;303. https://doi.org/10.1093/botlinnean/box096\\u003c/li\\u003e\\n\\u003cli\\u003eShrestha M, Dyer AG, Dorin A, et al (2020) Rewardlessness in orchids: how frequent and how rewardless? Plant Biol 22:555\\u0026ndash;561. https://doi.org/10.1111/plb.13113\\u003c/li\\u003e\\n\\u003cli\\u003eSilva KFO e., Melo BCV, Moreira TB, Williams TCR (2021) Darkness and low-light alter reserve mobilization during the initial growth of soybean (Glycine max (L.) Merrill). Theor Exp Plant Physiol 33:55\\u0026ndash;68. https://doi.org/10.1007/s40626-020-00194-7\\u003c/li\\u003e\\n\\u003cli\\u003eSinger RB (2002) The pollination biology of \\u003cem\\u003eSauroglossum elatum\\u003c/em\\u003e Lindl. (Orchidaceae: Spiranthinae): Moth-pollination and protandry in neotropical Spiranthinae. Bot J Linn Soc 138:9\\u0026ndash;16. https://doi.org/10.1046/j.1095-8339.2002.00003.x\\u003c/li\\u003e\\n\\u003cli\\u003eSinger RB, Cocucci AA (1999) Pollination mechanism in southern Brazilian orchids which are exclusively or mainly pollinated by halictid bees. Plant Syst Evol 217:101\\u0026ndash;117. https://doi.org/10.1007/BF00984924\\u003c/li\\u003e\\n\\u003cli\\u003eSinger RB, Sazima M (1999) The pollination mechanism in the \\u0026ldquo;\\u003cem\\u003ePelexia\\u003c/em\\u003e alliance\\u0026rdquo; (Orchidaceae: Spiranthinae). Bot J Linn Soc 131:249\\u0026ndash;262. https://doi.org/10.1006/bojl.1999.0270\\u003c/li\\u003e\\n\\u003cli\\u003eStpiczyńska M, Matusiewicz J (2001) Anatomy and ultrastructure of spur nectary of \\u003cem\\u003eGymnadenia conopsea\\u003c/em\\u003e (L.) Orchidaceae. Acta Soc Bot Pol 70:267\\u0026ndash;272. https://doi.org/10.5586/asbp.2001.034\\u003c/li\\u003e\\n\\u003cli\\u003eSwięczkowska E, Kowalkowska AK (2015) Floral nectary anatomy and ultrastructure in mycoheterotrophic plant, \\u003cem\\u003eEpipogium aphyllum\\u003c/em\\u003e Sw. (Orchidaceae). Sci World J 2015:1\\u0026ndash;11. https://doi.org/10.1155/2015/201702\\u003c/li\\u003e\\n\\u003cli\\u003eSzlachetko DL, Rutkowski P (2008) Classification of Spiranthinae, Stenorrhynchidinae and Cyclopogoninae. In: Rutkowski P, Szlachetko DL, G\\u0026oacute;rniak M (eds) Phylogeny and taxonomy of the subtribes Spiranthinae, Stenorrhynchidinae and Cyclopogoninae (Spirantheae, Orchidaceae) in Central and South America. Wydawanictwo Uniwersytetu Gdańskiego, Gdańsk, pp 130\\u0026ndash;222\\u003c/li\\u003e\\n\\u003cli\\u003eSzlachetko DL, Rutkowski P, Mytnik J (2005) Contributions to the taxonomic revision of the subtribes Spiranthinae, Stenorrhynchidinae and Cyclopogoninae (Orchidaceae) in Mesoamerica and the Antilles. Polish Bot Stud 20:3\\u0026ndash;387\\u003c/li\\u003e\\n\\u003cli\\u003eWatteyn C, Scaccabarozzi D, Muys B, et al (2023) Sweet as \\u003cem\\u003eVanilla hartii\\u003c/em\\u003e: Evidence for a nectar-rewarding pollination mechanism in \\u003cem\\u003eVanilla\\u003c/em\\u003e (Orchidaceae) flowers. Flora Morphol Distrib Funct Ecol Plants 303: 152294. https://doi.org/10.1016/j.flora.2023.152294\\u003c/li\\u003e\\n\\u003cli\\u003eWiemer AP, Mor\\u0026eacute; M, Benitez-Vieyra S, et al (2009) A simple floral fragrance and unusual osmophore structure in \\u003cem\\u003eCyclopogon elatus\\u003c/em\\u003e (Orchidaceae). Plant Biol 11:506\\u0026ndash;514. https://doi.org/10.1111/j.1438-8677.2008.00140.x\\u003c/li\\u003e\\n\\u003cli\\u003eWilmer P (2011) Pollination and floral ecology. Princeton University Press, Princeton, USA\\u003c/li\\u003e\\n\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":false,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":true,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"journal-of-chemical-ecology\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"joce\",\"sideBox\":\"Learn more about [Journal of Chemical Ecology](https://www.springer.com/journal/10886)\",\"snPcode\":\"10886\",\"submissionUrl\":\"https://submission.nature.com/new-submission/10886/3\",\"title\":\"Journal of Chemical Ecology\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false},\"keywords\":\"Apidae, floral histochemistry, Halictidae, hexose, nectar, raphids, Spiranthinae\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-4876023/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-4876023/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003e \\u003cem\\u003eCyclopogon\\u003c/em\\u003e is a large Neotropical orchid genus pollinated by halictid bees that offers nectar as reward. In a recent phylogenetic tree, \\u003cem\\u003eBrachystele guayanensis\\u003c/em\\u003e emerged nested within \\u003cem\\u003eCyclopogon\\u003c/em\\u003e and was transferred to that genus. The hypothesis for this study was that \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e would show a similar floral biology to \\u003cem\\u003eCyclopogon\\u003c/em\\u003e, although distinctive in its small, congested white flowers. Data on floral biology, pollinators, micromorphology, histochemistry, and nectar sugar composition of \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e in the Distrito Federal, Brazil were gathered. \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e is pollinated by at least four species of bees belonging to genera \\u003cem\\u003eExomalopsis\\u003c/em\\u003e, \\u003cem\\u003eNomada\\u003c/em\\u003e, \\u003cem\\u003eTetrapedia\\u003c/em\\u003e (Apidae) and \\u003cem\\u003eDialictus\\u003c/em\\u003e (Halictidae) foraging for nectar. Nectar is produced in visually imperceptible quantities by papillae on the inner surface of the labellum; similar papillae occur in other species of \\u003cem\\u003eCyclopogon\\u003c/em\\u003e but nectar class is unknown. \\u003cem\\u003eC. guayanensis\\u003c/em\\u003e nectar is hexose dominant (\\u0026lt;\\u0026thinsp;10% sucrose) in the Baker and Baker system and is the second record of this nectar class in the Orchidaceae. Pollinia are dorsally adhesive and probably attach to the underside of the bee labrum, as in other \\u003cem\\u003eCyclopogon\\u003c/em\\u003e. The inflorescence rachis, bracteoles, and outer surfaces of the base of the sepals are covered with lipid-secreting glandular trichomes; sepals and petals have numerous raphid-rich idioblasts. This is the first record of papillae on a spurless labellum shown to produce nectar in the Orchidoideae. We suggest that hexose dominant nectars in the Orchidaceae are associated with a geophytic habit, small pale flowers, exposed nectaries, visually imperceptible quantities of nectar, and a generalistic pollination system, and coin the term \\u0026lsquo;modest pollination strategy\\u0026rsquo; for this syndrome.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Cyclopogon Guayanensis is an Unusual Orchid With a Generalistic Pollination System and Hexose Dominant Nectar\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2024-09-03 11:36:41\",\"doi\":\"10.21203/rs.3.rs-4876023/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"decision\",\"content\":\"Revision requested\",\"date\":\"2025-02-01T14:37:05+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2024-09-18T06:36:10+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"43401544873780599814375678730592923930\",\"date\":\"2024-09-09T18:12:36+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"220015335635866585912938647639328452159\",\"date\":\"2024-09-09T11:05:18+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2024-08-12T14:24:29+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2024-08-12T14:22:32+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"checksComplete\",\"content\":\"\",\"date\":\"2024-08-08T13:20:41+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"Journal of Chemical Ecology\",\"date\":\"2024-08-07T15:59:45+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"journal-of-chemical-ecology\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"joce\",\"sideBox\":\"Learn more about [Journal of Chemical Ecology](https://www.springer.com/journal/10886)\",\"snPcode\":\"10886\",\"submissionUrl\":\"https://submission.nature.com/new-submission/10886/3\",\"title\":\"Journal of Chemical Ecology\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false}}],\"origin\":\"\",\"ownerIdentity\":\"c278a4d6-ff69-44b7-b57f-67267053d651\",\"owner\":[],\"postedDate\":\"September 3rd, 2024\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"published-in-journal\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2025-06-02T16:01:58+00:00\",\"versionOfRecord\":{\"articleIdentity\":\"rs-4876023\",\"link\":\"https://doi.org/10.1007/s10886-025-01611-4\",\"journal\":{\"identity\":\"journal-of-chemical-ecology\",\"isVorOnly\":false,\"title\":\"Journal of Chemical Ecology\"},\"publishedOn\":\"2025-05-28 15:57:33\",\"publishedOnDateReadable\":\"May 28th, 2025\"},\"versionCreatedAt\":\"2024-09-03 11:36:41\",\"video\":\"\",\"vorDoi\":\"10.1007/s10886-025-01611-4\",\"vorDoiUrl\":\"https://doi.org/10.1007/s10886-025-01611-4\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-4876023\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-4876023\",\"identity\":\"rs-4876023\",\"version\":[\"v1\"]},\"buildId\":\"qtupq5eGEP_6zYnWcrvyt\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}