Vines climbing, unarmed, usually becoming blackish when dried. Stem terete, 4--5 m, woody. Petiole 5--5.5 cm, narrowly winged for ca. 1/2 its length; abscission zone distal; tendrils well developed. Leaf blade ovate or ovate-oblong, ca. 18 × 10 cm, abaxially slightly white powdery. Male inflorescence of 1 umbel, basally not prophyllate; peduncle to 10 cm; umbel densely 50--100-flowered, base thickened. Male flowers: perianth greenish, campanulate; outer tepals linear-oblong, ca. 5 × 1.5 mm, slightly fleshy, inner ones slightly narrower; stamens ca. 3.2 mm; anthers ca. 1 mm. Female flowers and fruit unknown. Fl. Apr--May.

* Forested slopes; 1300--1600 m. NW Yunnan (Gongshan Drung-Nu Zu Zizhixian).