N.Vietnam, Bac Kan Prov., Cho Don Distr., Ban Thi Municipality, Phia Khao village, Lung Li locality 22°17′30′'N 105°31′16′'E.
Primary broadleaved evergreen closed wet forest on very steep slopes and cliffs of remnant mountains composed with highly eroded crystalline limestone near top of ridge at elev. 900-1000 m a.s.l.
Lithophytic herb on vertical shady cliffs. Flowers white, lip with yellowish-lemon central spot. Very common.
HLF 746 25 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.