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 herb on shadow vertical cliffs of N exposition. Flowers blue, leaves with white venation. Rare.
CBL 875 04 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)