Northern Vietnam, Ha Tinh Prov., Huong Son Distr., Son Kim Municipality, in the vicinity of Rao An village, around point 18°22′00′'N, 105°13′13′'E. Remnants of primary evergreen lowland seasonal broad-leaved forest on steep granite\shale slopes of rocky river canyon at 200-240 m a.s.l. Treelet about 2 m hg in open rocky steep slope. Flowers white. Rare.