FLORA OF VIETNAM Orchidaceae Callostylis rigida Blume
Son La Prov., Van Ho Distr., Xuan Nha Municipality, Muong An village, territory of Xuan Nha natural reserve.
Primary broad-leaved evergreen humid forest on very steep slopes and cliffs of remnant mountain composed by solid highly eroded crystalline limestone at elevation 800-1000 m a.s.l. around point 20°45′06.5″N 104°46′37.8″E.
Creeping epiphyte and lithophyte on rocky steep slope near mountain top. Not rare.