Vientiane prov., Kasi distr., Si Sang Vone village, around point 19°06'10.9''N 102°10'46.1''E. Secondary broad-leaved evergreen dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 600-700 m a.s.l. Climbing shrub to 3 m tall on steep rocky, rather open slope. Flowers white. Occasional.