N. Vietnam, prov. Cao Bang, distr. Nguyen Binh, municipality Ca Thanh (N 22°44′ E 105°50′). Primary semideciduous broad-leaved forest on steep slopes and bluffs of remnant karst limestone ridge at 1250-1300 elev. Terrestrial herb among shady rocks. Flowers light lilac. Common.
CBL 1281 13 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)