A new subspecies and new records of Trichosanthes (Cucurbitaceae) for India, and notes on T. khasiana

In India, knowledge of the geographic distribution of Trichosanthes species is inadequate, largely due to the lack of revisionary work. Based on field observations, collected specimens and data from herbarium specimens, this paper describes a new taxon –  T. dunniana subsp. clarkei from Sikkim and northern hill districts of West Bengal in northeastern India; and presents the first confirmed records of three southeast Asian taxa, viz., T. dunniana subsp. dunniana and T. wallichiana subsp. subrosea from northeastern India, and T. tricuspidata from the Andaman & Nicobar Islands. The name T. khasiana has been lectotypified, and Indochinese T. inthanonensis has been reduced under it. The southern Chinese Trichosanthes subrosea is transferred at reduced rank as T. wallichiana subsp. subrosea , while T. tridentata has been reduced to synonymy of this subspecies. Furthermore, we provide an updated distribution map with confirmed occurrences of these taxa in India, critical taxonomic notes and additional taxonomic characters.