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 closed evergreen broadleaved wet forest on steep slopes and cliffs of remnant limestone ridge at 650 m alt. Epilite herb on shadow wet rocks. Flowers greenish. Not rare.
CBL 1033 10 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)