Taxonomy of the Asian Gymnema latifolium (Apocynaceae, Asclepiadoideae,Marsde- nieae),including lectotypification of the synonymous G. khandalense

摘要

The Indian endemics Gymnerna khandalense and G. kollimalayanum are proposed as new synonyms of G. latifolium, and leclotypification for G. khandalense is provided. The description of G. latifolium, which is of wide distribution in Bangladesh, S China, India, Myanmar, Thailand and Vietnam, is emended with regard to coronal structures. A chromosome number is also provided for the first time. A (reduced) gynostegial corona for G. latifolium could be confirmed, putting the utility of corona characters for the separation between the genera Gymnema and Marsdenia into question. As a consequence of the reconsidered status of G. latifolium, this species and its synonyms need to be removed from the Indian Red Data List.