N. Vietnam, Bac Can prov., Na Ri distr., Kim Hy municipality, vicinities of Lung Hin Con village (N 22°17′ E 106°03′), 27 km to 55° of Bac Can city. Secondary shrubs on alluvial shale foothills of limestone ridge at elev. 500-550 m a.s.l. Forb vine up to 10 m lg in open wet places. Not rare.