N. Vietnam, prov. Cao Bang, distr. Thach An, municipality Thai Cuong, (N 22°21′ E 106°27′), about 39 km to SSE from Cao Bang town. Primary semideciduous broadleaved forest on steep slopes and bluffs of remnant limestone ridge at 500-550 m alt. Terrestrial and epilite herb up to 0.5 m hg in shadow place. Flowers white with purple tint, with purple stripes inside. Not rare.
CBL 850 03 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)