FLORA OF LAOS Orchidaceae Cleisostoma arietinum (Rchb.f.) Garay
Houphan Prov., Hem Distr., Na Puok village, Pu Tham Nhon mountain around point 20°10′00.0′'N 103°24′37.0′'E.
Primary and secondary broad-leaved evergreen dry forest on very steep rocky mountain slopes composed by solid marble-like highly eroded limestone at elev. 1050-1150 m a.s.l.
Epiphyte on old trees on mountain top. Flowers white to light yellowish, lip apex and column purple. Very common.