N. Vietnam, prov. Cao Bang, distr. Ha Lang, municipality Duc Quang, vicinities of Lung Hoai village (N 22°43′ E 106°40′), about 43 km to E from Cao Bang town. Primary open coniferous and mixed semideciduous forest (with Pinus kwangtungensis and Pseudotsuga brevifolia) along tops of remnant limestone ridge at 600-650 m alt. Epilite herb up to 1.5 m hg on open rocks. Flowers lilac. Not rare.
CBL 765 28 Nov. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)