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. Tree 15-20 m tall on rocky slope. Flowers and inflorescence green. Common.