N.Vietnam, Bac Kan Prov., Cho Don Distr., Ban Thi Municipality, village Phia Khao, around point 22є16'10''N, 105є31'01''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. Treelet about 5 m tall. Syconia dull green. Occasional.