Border area between Phieng Luong municipality (Ha Giang Prov., Bac Me Distr.) and Sinh Long municipalitiy (Tuen Quang Prov., Na Hang Distr.).
Primary broad-leaved humid evergreen and mixed forest on very steep slopes and along rocky ridge composed with solid crystalline highly eroded limestone at elevation 1100-1170 m a.s.l. around point 22°38′24.3″N 105°20′21.3″E.
Creeping short epiphytic vine in shady wet place on shady alluvial bottom of limestone mountain. Flowers white outside, dark brown-violet inside tube. Occasional.