Vientiane prov., Kasi distr., between Pa Chao and Nam Ken villages, Pa Chao Mt., around point 19°19′50.6′'N 102°21′20.5′'E.
Secondary broad-leaved evergreen dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 1000-1100 m a.s.l.
Large woody vine in open rocky slope. Flowers dirty greenish. Not common.