N. Vietnam, prov. Cao Bang, distr. Ha Lang, municipality Dong Loan, vicinities of Ban Lung and Lung Phuc (N 22°46′ E 106°44′), about 50 km to E from Cao Bang town. Secondary evergreen forest on alluvial walley among limestone rocks on foothills of remnant limestone ridges at 400
m alt. Epilite herb on shadow wet steep slopes. Flowers pink, leaves uniformly light green. Common.
CBL 606 24 Nov. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)