N.Vietnam, Bac Kan Prov., Na Ri Distr., Liem Thuy Municipality, village Lung Vai, around point 21º57'18''N, 106º06'12''E, at elevation 500-700 m a.s.l. Primary broad-leaved evergreen closed wet forest on very steep slopes and cliffs of rocky ridges and mesae composed with white solid marble-like crystalline limestone. Terrestrial and lithophytic herb on very steep rocky slope. Flowers: tepals light yellowish-green with light violet tint, lip deep violet. Leaves dull light gray-green. Occasional.