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 herb in shady rocky place. Very common and abundant from elevation 800 m to the top of mountain. Old, dry flowers dull gray. Leaves uniform green.