Hoa Binh Prov., Lac Son Distr., Tu Do Municipality, Mon village, around point 20°25′29”N 105°19′36”E.
Primary broadleaved forest on steep rocky slopes of remnant mountain composed with solid crystalline highly eroded limestone at elevation about 500-700 m a.s.l.
Treelet 3-4 m (to 8 m) tall. Flowers yellow. Occasional.