Vientiane Prov., Kasi Distr., Thong Mout village, around point 19°26′51.5”N 102°07′45.8”E.
Primary broad-leaved evergreen forest on very steep rocky slopes and on vertical cliffs of remnant highly eroded rocky limestone mountains composed by solid crystalline stratified limestone at elevation 1550-1650 m.
Woody vine 10-15 m long on rocky slope. Flower dark brown-purple. Not common.