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. Epilite herb on open wet limestone rocks along stream on alluvial valley between remnant limestone ridges at 600 m alt. Very common.
CBL 1149 12 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)