Luang Prabang prov., Ngoy distr., Ngoy village, around point 20°42'52.9''N 102°41'15.5''E.
Remnants of primary evergreen forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 800-900 m a.s.l. Treelet 4-6 m tall in open place among secondary shrubs. Flowers yellowish. Common.