N. Vietnam, prov. Cao Bang, distr. Thach An, municipality Thuy Hung, vicinities of Na Lit village (N 22°30′ E 106°27′), about 27 km to SE from Cao Bang town. Primary evergreen broadleaved closed dry forest on steep slopes and bluffs near tops of remnant limestone ridge at 450-500 m alt. Epilite and terrestrial herb on very steep slopes and bluffs. Flowers dirty reddish. Very common.
CBL 879 04 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)