Northern Vietnam, Tuyen Quang Prov., Chiem Hoa Distr., Binh An Municipality, in the vicinity of point 22°25′38′'N, 105°10′00′'E. Secondary evergreen seasonal broad-leaved forest with bamboo on highly eroded remnant ridge composed with soft stratified limestone and lime schist consolidated with numerous quartzite dikes at elev. 450-550 m a.s.l. Terrestrial and lithophytic herb up to 1 m hg on rocky shady very steep slope. Flowers deep purple, anther and stigma yellow. Leaves deep green above, deep uniform purple beneath. Stem and petioles light green. Common.