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. Climbing shrub to 2 m tall on open rocky mountain slope. Flowers white. Occasional.