FLORA OF VIETNAM Orchidaceae Dendrobium williamsonii Rchb.f.
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.
Epiphyte on old mossy trees near top of ridge. Not rare.
CPC 1088c 18 December 2010 Coll.: L.Averyanov, P.K.Loc, P.V.The, N.T.Vinh.
Fl. under cultivation in June 2012. Tepals white to light yellowish, lip white with orange center and orange side lobes.