Vietnam, Lang Son Prov., Bac Son Distr., Tan Tri Municipality, around Na Mau village, Khau Kieng ridge composed with shale.
Deeply degraded remnants of primary and secondary broadleaved evergreen wet forest with bamboo at elevation 800-1100 m a.s.l. Terrestrial sedge on shady rocky slope. Inflorescences pinkish. Common.