Twining shrubs; branchlets with sparse or very sparse lenticels; lenticels broadly elliptic or approximately orbicular. Petiole 1.2-2 cm; leaf blade broadly ovate, broadly ovate-elliptic, or nearly orbicular, 6-13.5 × 3.5-9.5 cm, papery, abaxially powdery white, base widely rounded, sometimes decurrent, margin shallowly serrate or obtusely serrulate, apex shortly acuminate; secondary veins 5-7 pairs, curved, approximately parallel. Inflorescences terminal and axillary, terminal inflorescences many flowered, 3-7 cm, axillary ones 3-7-or more flowered; rachis short; pedicels 2-4 mm, jointed at or below middle. Sepals large, globose, 2-3 mm wide, ciliate, apex obtusely orbicular-triangular; petals elliptic or orbicular-elliptic, ca. 4.5 × 2.5-3 mm. Disk cupuliform, margin approximately truncate. Stamens slightly shorter than corolla; anther ovate, apex often apiculate. Infructescence 3-7 cm, stipe sturdy, 5-10 × ca. 1.5 mm. Capsule globose, adaxially brown maculate. Seeds convex to slightly crescentiform, 4.5-6 × 2-3 mm, blackish brown. Fl. May-Jun, fr. Aug-Nov.