Hoa Binh Prov., Lac Son Distr., Tu Do Municipality, Mon village, around point 20°24′52”N 105°19′41”E.
Secondary evergreen dry broad-leaved forest on steep rocky slopes of remnant mountain composed with highly eroded marble-like solid crystalline limestone at elevation about 300 m a.s.l.
Herbaceous vine 5-6 m long in open rocky place. Flowers yellow-orange. Not rare.