FLORA OF VIETNAM Orchidaceae Dendrobium williamsonii
Northern Vietnam, Ha Giang Prov., Quan Ba Distr., Can Ty Municipality, in the vicinity of Lung Vai village at left side of Mien River, around point 23°05′09′'N, 105°03′23′'E. Primary coniferous forest with Pseudotsuga brevifolia and Tsuga chinensis on remnant highly eroded limestone ridge at elev. 1440 m a.s.l. Epiphyte. Flowers light yellow, lip reddish-orange at the center. Occasional.