Vines woody. Branches subterete, shallowly 8-grooved, sparsely pilose or subglabrous. Leaves ternate; petiole 5.5--6.8 cm; leaflet blades narrowly ovate or broadly lanceolate, 7--8.8 × 2.5--3.4 cm, thinly papery, both surfaces glabrous or sparsely pilose on midvein near base abaxially, base rounded, margin entire, apex attenuate or long acuminate; basal veins abaxially slightly prominent. Cymes axillary, ± paniclelike, ca. 10-flowered; peduncle 4.4--4.8 cm, subglabrous; bracts triangular, ca. 3.5 mm, sparsely ciliolate. Flowers ca. 1.2 cm in diam.; pedicel slender, 1.2--2.2 cm, sparsely appressed puberulous. Sepals 4, oblong, ca. 11 × 4 mm, both surfaces glabrous, margin velutinous abaxially, apex acute. Stamens 5--8 mm, glabrous; anthers linear, 3.2--3.8 mm, apex obtuse or sometimes indistinctly minutely apiculate. Ovaries densely puberulous; style ca. 6 mm, densely villous. Fl. Jun.

* E Guangxi (Dayao Shan).