Luang Prabang prov., Ngoy distr., Ngoy village, Pha Noi Mountain, around point 20°42'53.6''N 102°40'34.7''E.
Remnants of primary evergreen forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 400-450 m a.s.l. Leafless succulent treelet to 5 m tall on mossy rocky mountain top. Flowers yellowish-green. Very common, forest co-dominant on rocky mountain tops.