FLORA OF VIETNAM Orchidaceae Oberonia ensiformis (Sm.) Lindl. Dien Bien Prov., Muong Cha Distr., Mua Ngai Municipality, around point 21°52’19”N 103°10’01”E. Remnants of primary evergreen broad-leaved forest on very steep rocky slopes and on tops of remnant mountain composed with highly eroded marble-like solid crystalline limestone at elevation 1150-1250 m a.s.l. Lithophytic herb on vertical shady cliff. Flowers yellow. Very common. CPC 1062 18 December 2010 Photos. Coll.: L.Averyanov, P.K.Loc, P.V.The, N.T.Vinh.