N. Vietnam, Son La prov., Moc Chau distr., Van Ho municipality, near Hua Tat village (20°46′13′'N, 104°46′12′'E). Primary broad-leaved evergreen closed wet forest along remnant limestone highly eroded ridge at elev. 1100-1300 m a.s.l. Tree 6-8 m hg on top of ridge. Flowers light pink, central petal inside with greenish tint. Rare.