Son La Prov., Moc Chau Distr., Chieng Hac Municipality, around point 20°51′50″N 104°31′17″E.
Broad-leaved evergreen dry forest on steep slopes and on tops of ridge composed with rocky crystalline solid marble-like highly eroded limestone at elev. 750-800 m a.s.l.
Lithophytic herb on shady cliff. Rare.
HAL 9425 31 Oct. 2006 DNI fix. Coll.: Nguyen Tien Hiep, L.Averyanov, Pham Van The.