FLORA OF VIETNAM Plants of Phong Nha - Ke Bang National Park Apocynaceae Alstonia guangsiensis
Vietnam, Quang Binh Prov., Minh Hoa Distr., Thuong Hoa Municipality, about 1-1.5 km to SW of Ban On village (17°40′21′'N, 105°58′00′'E). Ca Xach mountain (17°39′20′'N, 105°57′42′'E).
Primary closed evergreen broad-leaved gnarled stunted forest along rocky ridge composed with solid marble-like highly eroded crystalline limestone at elevation 600-800 m a.s.l.
Shrub up to 5 m tall on tops of ridge. Occasional.