Vines woody. Branches shallowly longitudinally grooved, glabrous, turning black on drying; scales of axillary floral bud lanceolate, 0.8--2 cm, brownish velutinous. Leaves ternate or pinnate, 5-foliolate, glabrous; petiole 4--6 cm; leaflet blades narrowly lanceolate, 6--14 × 1--2 cm, subleathery, base cuneate to cuneate-rounded, margin entire, apex falcate-acuminate. Cymes axillary, many flowered; peduncle 8--9.5 cm; bracts linear-lanceolate, often 3-lobed, brownish puberulous. Flowers 3--3.5 cm in diam. Pedicel 1--2 cm, glabrous. Sepals 4, spreading, linear-lanceolate to oblanceolate, 1.5--1.8 × 0.2--0.5 cm, abaxially glabrous except for velutinous margin, adaxially glabrous, apex obtuse to ± acute. Stamens 5--8 mm, glabrous; anthers linear to narrowly oblong, 2.8--3 mm, apex obtuse. Ovaries pubescent. Style ca. 5 mm, densely villous.

* Guizhou (Anshun Shi).