Vietnam, Quang Tri Prov., Huong Hoa Distr., Huong Phung Municipality, Sa Mui pass, around point 16°48′36″N 106°34′44″E at elevation about 1300-1400 m a.s.l.
Primary and secondary broad-leaved evergreen submontane forest on very steep rocky shale southern slopes of Sa Mui Mountain.
Coll. N.T.Hiep, L.Averyanov, P.K.Loc, P.V.The, N.S.Khang, P.H.Duc, L.T.Son, S.Bounphanmy, T.K.Ratana, O.Sonliya, T.Q.Dang, N.V.Hien, H.T.N.Trang, L.T.Chau. Grant from Henry Luce Foundation.