N. Vietnam, prov. Cao Bang, distr. Ha Lang, municipality An Lac, vicinities of Phia Deng village (N 22°43′ E 106°36′), about 36 km to E from Cao Bang town. Primary evergreen closed broadleaved forest on steep slopes of remnant limestone ridge at 500-600 m alt. Epilite herb up to 0.4 m hg on shadow vertical cliffs. Not rare.
CBL 785 29 Nov. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)