Son La Prov., Moc Chau Distr., Chieng Son comm., Hin Pen village, around point 20°42′36.7N 104°35′11.0E.
Primary and secondary evergreen broad-leaved forest on very steep slopes and cliffs of highly eroded red-brown sandstone at elevation about 1200 m a.s.l. Terrestrial and lithophytic herb in shady rocky place. Flowers white. Very common.