Luang Prabang prov., Pon Xay distr., Houay Man village, Phou Pak Sang Mountain, around point 19°59′03.8′'N 102°25′09.0′'E.
Degraded primary evergreen and semideciduous forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 1000-1150 m a.s.l. Creeping semi-woody epiphytic and lithophytic vine to 5 m long on mountain top. Flowers pinkish. Common.