N.Vietnam, Bac Kan Prov., Cho Don Distr., Ban Thi Municipality, Phia Khao village, Cau Muc locality 22°17′32′'N 105°31′27′'E.
Primary closed evergreen wet broadleaved forest on very steep slopes and cliffs of remnant mountains composed with highly eroded crystalline limestone near top of ridge at elev. 720 m a.s.l.
Lithophytic herb on open mossy cliffs. Flowers very fragrant, anthers dull pinkish. Common.
HLF 794 26 Dec. 2002.
Coll. Phan Ke Loc, L.Averyanov, Nguyen Anh Duc, To Van Thao, Mai Van Xinh, Nguyen Tien Vinh. Grant from Henry Luce Foundation.