N. Vietnam, prov. Cao Bang, distr. Ha Lang, municipality An Lac, vicinities of Phia Deng village (N 22°43′ E 106°36′), about 36 km to E from Cao Bang town. Secondary broadleaved remnant forest along stream on alluvial valley between limestone ridges at 500 m alt. Epilite herb or shrublet up to 1 m hg on open stream limestone rocks. Flowers pale violet. Not common, but sporadically abundant.
CBL 779 29 Nov. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)