Northern Vietnam, Lao Cai Prov., Van Ban Distr., to the west of Nam Xay village (around point 21°59′00′'N, 104°02′00′'E). Secondary broad-leaved evergreen mountain forest with bamboo on granite and quartzite very steep slopes at elev. 700-900 m a.s.l. Woody vine up to 20 m lg. Not rare.