Lianas to 6 m. Branchlets tawny brown, lenticellate. Petiole 1-3 cm, rusty pubescent; leaf blade elliptic, 6.5-8.5 × 3.4-5.2 cm, subleathery, adaxially glabrous, abaxially rusty puberulent, soon glabrescent, base cuneate, apex acuminate; lateral veins 5-7 pairs. Cymes shorter than leaves, 3-9-flowered, fragrant, rusty tomentose; peduncle 2-4 cm. Pedicel 3-5 mm. Calyx glands 5. Corolla yellow or brown; tube ca. 4 × 3 mm; lobes lanceolate, ca. 6 × 2 mm. Corona lobes 5, reddish, apex 2-cleft, with a short adaxial appendage. Anther appendages orbicular, pollinia elliptic. Stigma head fusiform, tapering to a slender point, twice as long as anthers. Fl. Apr-Jul.

* Humid open woods along valleys; 100-600 m. Hainan.