Ha Giang prov., Quan Ba distr., Tung Vai commune, Thang village, around point 23°03ʹ13.4ʺN 104°51ʹ48.8ʺE, steep rocky slopes of stream valley composed with eroded stratified highly eroded limestone at elevation 1000-1200 m a.s.l. Primary evergreen broad-leaved very humid forest. Semi-woody vine 8-10 m long in open rocky slope. Flowers pale yellow. Not common. 23 April 2018, L. Averyanov, Nguyen Sinh Khang, Nguyen Tien Hiep, Nguyen Quang Hieu, Chuong Quang Ngan, T. Maisak, VR 738 (HN, LE01050103). Det.: M. Rodda 11.10.2019.