N. Vietnam, Prov. Thai Nguyen, distr. Dai Tu, vicinities of Tam Dao town, NE macroslope of Tam Dao ridge at 950-1000 m alt. (N 21°27′ E 105°38′). Closed wet evergreen broad-leaved primary forest on very steep mt slope. Prostrate and pendant epilitic herb on vertical rocky bluffs and very steep slopes. Very common. Usual dominant of forb forest stratum at 1000 m alt. VH 5039 31.05.1997 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 5803-96)