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 broad-leaved evergreen submontane forest on very steep rocky shale southern slopes of Sa Mui Mountain.
Lithophytic herb on shady vertical rocky cliffs along rocky ridge edge. Flowers white, anther yellow. Occasional.
HLF 5844 29 March 2006.
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.