Vientiane Prov., Vang Vieng Distr., Na Po village, about 12 km to the W of Vang Vieng town, Pa Nang Oua Mt., around point 18°55′44.9”N 102°20′20.1”E.
Dry broad-leaved primary and secondary evergreen and semideciduous forest on very steep rocky slopes and on vertical cliffs of remnant highly eroded rocky limestone mountains composed by solid crystalline limestone at elevation 600-900 m.
Terrestrial herb to 1 m tall on shady rocky slope. Flowers dark violet. Occasional.