Herbs twining, to 2 m, glabrous except for flowers. Petiole 1-1.5 cm; leaf blade ovate or ovate-oblong, membranous, 3-6 × 1.5-2.5 cm, base cordate, apex caudate-acuminate; lateral veins 7-9 pairs, somewhat flattened, glabrous. Inflorescences 1- or 2-flowered, up to as long as leaves; peduncle slender, 0.8-2 cm. Pedicel ca. 1 cm. Sepals lanceolate, ca. 2 × 0.5 mm, ciliate. Corolla with pale green and purplish spots and stripes, glabrous; tube ca. 2 cm, funnelform above swollen base; lobes ligulate, ca. 6 × 2 mm. Outer corona shallowly lobed; lobes 2-cleft at apex, pilose; inner lobes ligulate and longer than gynostegium. Fl. Apr-Aug.

* Valleys; 300-900 m. Hunan, Sichuan.