Quang Binh Prov., Minh Hoa Distr., Thuong Hoa Comm., Ban On Vill., Con Moong mt. (about 1 km N on walking trail from Ban On to Thuong Hoa), 17°40′59″N, 105°57′56″E, 250-280 m.
On edges of heavily logged primary evergreen broad-leaved forests on foot of limestone mts. and on stream banks.
Small herbaceous vine, up to 10-15 m long. Flowers whitist-yellowish. Rare.