N.Vietnam, Bac Kan Prov., Cho Don Distr., Ban Thi Municipality, village Phia Khao, around point 22°16′10′'N, 105°31′01′'E at elevation
700-850 m a.s.l. (Tang Gia mountain).
Primary broad-leaved evergreen closed forest on very steep slopes and cliffs near and on tops of rocky ridge composed with solid marble-like stratified limestone.
Lithophyte on wet travertine deposits on vertical shady cliffs. Flowers blue. Common.