Vientiane Prov., Kasi Distr., Thong Mout village, around point 19°25′19.7”N 102°08′32.7”E.
Primary broad-leaved evergreen forest on very steep slopes and on cliffs of remnant mountain composed with solid crystalline highly eroded limestone at elevation about 1550 m.
Woody vine to 10 m long on very steep shady rocky slope. Flowers white to light yellowish, very fragrant. Common.