Hoa Binh Prov., Lac Son Distr., Ngoc Son Municipality, Khu village, around point 20°26′31”N 105°19′32”E.
Primary broadleaved forest on steep rocky slopes of remnant mountain composed with solid crystalline highly eroded limestone at elevation about 550-650 m a.s.l.
Terrestrial herb on shady rocky slope. Flowers white. Locally common.