N. Vietnam, prov. Cao Bang, distr. Bao Lac, municipality Yen Lac, vicinities of Yen Lac village (N 22°44′ E 105°50′). Secondary open shrubs on shale alluvial valley between limestone remnant karst ridges along stream at 1050-1100 m elev. Terrestrial herb 0.5-1 m hg in open wet place. Flowers white with violet tint. Common.
CBL 1437 16 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)