Vientiane prov., Kasi distr., between Pa Chao and Nam Ken villages, Pa Chao Mt., around point 19°19'50.6''N 102°21'20.5''E.
Secondary broad-leaved evergreen dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 1000-1100 m a.s.l. Shrub of treelet 3-4 m tall on steep open rocky slope. Flowers white. Common.