Vietnam, Quang Binh Prov., Bo Trach Distr., Tan Trach Municipality, vicinities of A Rem village (17є23'32''N, 106є12'46''E). Heavily logged primary closed evergreen broad-leaves forest on steep slopes of rocky ridge composed with solid marble-like highly eroded stratified crystalline limestone at elevation about 650-750 m a.s.l.