N. Vietnam, prov. Cao Bang, distr. Ha Lang, municipality Thang Loi, vicinities of Ban Hao (N 22°43′ E 106°40′), about 43 km to E from Cao Bang town. Secondary evergreen broadleaved closed forest among limestone rocks on alluvial valley and on foothills of remnant limestone ridges at 300-400 m alt. Terrestrial and epilite fern on steep slopes and bluffs. Very common.
CBL 669 26 Nov. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)