Ha Giang prov., Quan Ba distr., Tung Vai commune, Thang village, around point 23°03ʹ00.4ʺN 104°52ʹ02.2ʺE, steep rocky slopes of river valley composed with eroded limestone at elevation 1000–1060 m a.s.l. Remnants of primary evergreen broad-leaved very humid forest. Prostrate herb among wet open river rocks. Not common. 19 October 2018, L. Averyanov, Nguyen Sinh Khang, T. Maisak, Truong Quang Ngan, VR 1042 (HN, LE01049117).