N. Vietnam, Lang Son prov., Huu Lung distr., Huu Lien municipality (N 21°40′ E 106°22′). Primary wet evergreen broadleaved forest on steep slopes of remnant karst limestone ridge at elev. 200 m a.s.l. Vine up to 8 m long in open place. Flowers dirty purple. Not common.
NTH 3268 02 Oct. 1999
Collectors: N.T. Hiep, N.Q. Binh, L. Averyanov, P. Cribb.