Son La Prov., Moc Chau Distr., Chieng Son comm., Pha Luong village, Pha Luong Mountains. Primary and secondary evergreen broad-leaved forest on very steep slopes and cliffs of highly eroded red-brown sandstone at elevation 1000-1050 m a.s.l. around point 20°42’02.1N 104°37’23.1E. Undershrub to 1.5 m tall in shady rocky place. Flowers yellow. Common.