N.Vietnam, Cao Bang Prov., Trung Khanh Distr., Ngoc Khe Municipality, Pac Nga village, around point 22°54′59′'N, 106°31′44′'E, at elevation 800-850 m a.s.l.
Remnants of primary broad-leaved evergreen and coniferous forest along rocky tops of rocky ridges and mesae composed with light gray solid marble-like highly eroded crystalline limestone.
Tree 4-8(12) m tall. Common. Occasional co-dominant of 1-2 forest stratum. HAL 5640 11 June 2004