Stems twining, more than 1 m; branches short, less than 3 cm, with 2-4 leaves, sterile or with terminal flowers, sparsely puberulent or glabrescent at internodes. Leaves on main stems alternate, those on branches subopposite; petiole 0.2-2 cm, puberulent; blade abaxially gray-green, adaxially green, ovate-lanceolate or lanceolate, 3-15 × 1-7 cm, abaxially appressed puberulent, adaxially puberulent, base decurrent or cuneate, margin conspicuously dentate, apex acuminate. Flowers solitary, terminal on branches; pedicels ca. 1 cm, puberulent. Calyx tube adnate to ovary up to middle, semiglobose, puberulent or gradually glabrescent; lobes distant from each other, triangular, 6-10 × 3-7 mm, apex acute, puberulent and ciliate, sinus between lobes broad and obtuse. Corolla campanulate or ± tubular-campanulate, 1.5-3 cm; lobes triangular, glabrous. Stamens glabrous; filaments slightly dilated at base, ca. 7 mm, glabrous; anthers ca. 5 mm. Capsule ca. 1.5 cm in diam. Fl. and fr. Jul-Sep.

● Forest margins, scrub; 2300-3800 m. Chongqing, W Hubei, N Sichuan.