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. Primary mixed semideciduous forest (with Pseudotsuga brevifolia) along tops of limestone ridge at 900-1000 m alt. Epilite fern on steep slopes and on vertical cliffs in shadow places. Not rare.
CBL 1126 12 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)