A new species in Iris section Pseudoregelia (Iridaceae) from Gansu, China

Iris longnanensis Z.F. Bai, Y.E. Xiao, F.Y. Yu (Iridaceae: subgenus Iris section Pseudoregelia), a novel herbaceous species native to the arid and thermal valleys of Longnan city, Gansu province, China, is herein described and illustrated. Morphologically akin to I. leptophylla Lingelsheim, I. longnanensis is distinguished by its dense, persistent foliage and strikingly short new leaves (6.6–15.1 cm) during the blooming season, along with its distinctive purplish-brown flowering stem. Phylogenetic analyses based on chloroplast DNA sequences corroborate the classification of I. longnanensis within section Pseudoregelia, highlighting the significance of this new species discovery for understanding the evolution and diversity within the genus.