N. Vietnam, prov. Cao Bang, distr. Bao Lac, municipality Yen Lac, vicinities of Yen Lac village (N 22°44′ E 105°50′), about 44 km to NWW from Cao Bang town. Secondary open shrubs among limestone rocks on alluvial foothills of limestone remnant ridge at 1100 m alt. Herb up to 0.5 m hg in open wet places. Not common.
CBL 431 18 Nov. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)