Description from Flora of China
Rootstocks a cluster of fusiform roots. Stems twining to 2 m, glabrous to sparsely pilose. Leaf blade linear or linear-lanceolate, 3.5-9 cm × 2-7 mm, base cuneate, apex ± acute, adaxially short pilose, abaxially subglabrous or glabrous. Inflorescences (1- or) few flowered; peduncle 1-6 mm. Pedicel to 1.4 cm. Sepals linear or linear-lanceolate, 5-7 mm, glabrous or ciliate; glands 16-20. Corolla 3-5 cm; tube 2.6-3 cm, inflated base 5.5-8 mm wide, abruptly narrowed to ca. 3 mm wide and then widening to 8.5-10 mm at base of lobes; lobes oblong-elliptic, 0.9-1.6(-2) cm, sparsely pilose, ciliate. Outer corona lobes 2-toothed, teeth triangular, blunt, ca. as high as gynostegium, ciliate; inner lobes linear, subobtuse, glabrous. Follicles fusiform, 8-9 cm × ca. 3 mm, striate. Seeds oblong, ca. 7 × 3 mm; coma ca. 2 cm. Fl. Jun.
* Montane forests, thickets; 1900-2600 m. Sichuan.