Ha Giang prov., Quan Ba distr., Tung Vai commune, Thung Pang village, around point 23°04ʹ38.6ʺN 104°56ʹ06.8ʺE, steep rocky slopes near hill top composed with stratified highly eroded limestone at elevation 1000–1100 m a.s.l. Remnants of primary evergreen broad-leaved very humid forest. Lithophytic clustering herb on mossy rocks. Flower buds white. Common. 17 October 2018, L. Averyanov, Nguyen Sinh Khang, T. Maisak, Truong Duc Thieu, VR 874 (HN, LE01037398).