N. Vietnam, prov. Cao Bang, distr. Tra Linh, municipality Quang Vinh (N 22°51′ E 106°14′), about 21 km from Cao Bang town to the N. Primary evergreen closed wet forest on steep slopes and bluffs of remnant limestone ridge at 650-800 m alt. Epilite and terrestrial herb on steep slope and on vertical cliffs. Flowers dirty purple ? Very common.
CBL 981 09 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)