N. Vietnam, prov. Cao Bang, distr. Tra Linh, municipality Luu Ngoc, vicinities of Lung Mu village (N 22°47′ E 106°18′), about 14 km from Cao Bang town to the N. Primary coniferous and mixed semideciduous open forest (with Pseudotsuga brevifolia) along tops of limestone ridge at 800 m alt. Epilite herb up to 0.6 m hg. Common dominante of herb forest stratum.
CBL 1191 13 Dec. 1998 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)