Vietnam, Quang Binh Prov., Bo Trach Distr., Hung Trach Municipality, Khe Ba Tanh locality, around point 17°27'24''N, 106°23'14''E at elev. 600-700 m a.s.l. Slightly logged primary closed broad-leaved evergreen forest on slopes of mountains composed with shale, sandstone and occasionally granite, along rocky stream valley. Terrestrial and lithophytic small undershrub on open rocky wet slope. Flowers white-greenish. Not common.