Abstract
Veratrum chiengdaoense K.Larsen from northern Thailand is treated as a synonym of V. mengtzeanum O.Loes. from Yunnan, China, since there is no significant difference between them. Veratrum mengtzeanum is recorded for the first time from Thailand. This species seems closely allied to V. virginicum (L.) Aiton and V. latifolium (Desr.) Zomlefer indigenous to eastern North America, as they share clawed tepals with a pair of prominent nectaries.
