Northern Vietnam, Lao Cai Prov., Van Ban Distr., to the west of Nam Xay village (21°58′42′'N, 104°00′37′'E). Primary evergreen wet broad-leaved montane forest (on granite and quartzite) with bamboo on lower part of slope along small rocky stream at elev. 1650 m a.s.l. Woody vine or climbing shrub 2-3 m long. Not rare.