N. Vietnam, prov. Cao Bang, distr. Tra Linh, municipality Co Muoi, vicinities of Lung Dat village (N 22°51′ E 106°14′), about 22 km from Cao Bang town to the N. Secondary open broadleaved forest and shrubs on foothills of remnant limestone ridge at 600-650 m alt. Terrestrial herb in open place. Flowers light violet. Common weed in the area. CBL 1147 12 Dec. 1998 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)