Catasetum × goulartii (Orchidaceae, Catasetinae), a new nothospecies from the Brazilian Amazon in the subgenus Catasetum

In this work we propose a new natural hybrid of Catasetum , member of the subgenus Catasetum . More precisely it belongs to the section Isoceras , subsection Convergentes , since it has symmetrical and convergent antennae like it is observed in its two supposed parents ( C. sophiae and C. rivularium ). It has been found in an igapó vegetation on the banks of the Puduari River, in the central Brazilian Amazon. We give a detailed description of the taxon as well as a photographic plate and comments on its distribution, habitat and phenology. It is compared to its supposed parents, two sympatric species. Moreover, we propose an identification key to the species and nothospecies with symmetrical and convergent antennae found in Brazilian Amazon.