Northern Vietnam, Lao Cai Prov., Van Ban Distr., Khanh Yen Ha municipality, to the S of Na Nheo village (in the vicinity of point 21°59′04′'N, 104°15′08′'E). Primary closed broad-leaved evergreen submontane forest on steep granite and quartzite slopes of mountain stream canyon at elev. 850-950 m a.s.l. Epiphytic vine 8-10 m lg. Inflorescence white. Common.