Ha Giang prov., Quan Ba distr., Bat Dai Son commune, Bat Dai Son Nature Reserve, San Chu village, around point 23°08ʹ55.1ʺN 104°59ʹ45.7ʺE, 1100-1200 m a.s.l., karstic, highly eroded mountains composed of solid marble-like limestone, primary evergreen broad-leaved humid forest on very steep rocky slopes. Lithophytic climbing shrub with stems 3-4 m long in rather open place. Flowers light yellowish-green. Occasional. 13 April 2018, L. Averyanov, Nguyen Sinh Khang, Chuong Quang Ngan, T. Maisak, VR 013 (HN, LE01054019, LE01054020).