N. Vietnam, prov. Cao Bang, distr. Tra Linh, municipality Quang Vinh (N 22°48′ E 106°17′), about 16 km from Cao Bang town to the N. Remnants of primary evergreen broadleaved forest on alluvial valley between remnant limestone ridges at 600 m alt. Creeping epilite herb on open dry rocks. Leaves belw deep purple-violet. Very common.
CBL 1091 11 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)