形态特征：Shrubs, scandent, evergreen, 1–5 m tall. Branches grayish yellow, terete; branchlets green, slender, pubescent, slightly compressed and inconspicuously grooved when young. Leaves opposite, simple; petiole 1–3 mm long, slightly twisted, articulate near middle, sulcate adaxially, pubescent; leaf blade ovate or lanceolate, sometimes broad- ly ovate, 2.8–6.3 cm long, 0.9–2.5 cm wide, papery, with entire margin, slightly revolute, base broadly cuneate, rounded or subtruncate, sometimes cuneate or subcordate, slightly oblique, apex acuminate to caudate-acuminate, adaxially pubescent along midvein, and sparsely pubescent near apex when young, abaxially yellow glandular dotted and vein ax- ils with hair tufts; midvein slightly impressed adaxially, elevated abaxially, lateral veins 3–6 pairs, slightly elevated on both surfaces, arcuate-ascendant, anastomosing near margin. Flowers 1 (or 3) in terminal cymes, solitary in leaf axils, dimorphic. Peduncle 1–9 mm long, slightly pubescent. Bracts subulate-filiform, 2–3 mm long, glabrous. Pedicel 1.1– 1.6 cm long, glabrous. Calyx campanulate, glabrous; tube 3–4 mm long; lobes 5, linear, (2–) 2.5–4 (–4.5) mm long. Corolla white, salverform; tube 1.3–2.3 cm long, ca. 1.5 mm in diam; lobes 5, lanceolate, 8–11 mm long, 2–3 mm wide, apex argute. Thrum flowers: stamens 2; filaments ca. 1 mm long, glabrous; anthers 12.7–13.6 mm above base of co- rolla tube, 6.1–7 mm long; stigma 1.5–2.4 mm long, 2-lobed; style filiform, 3.9–5 mm long, glabrous; ovary 0.9–1 mm long, glabrous. Pin flowers: stamens 2; filaments ca. 1 mm long, glabrous; anthers 10.8–11.7 mm above base of corolla tube, 5.4–5.6 mm long; stigma 1.9–2.9 mm long, 2-lobed; style filiform, 13.4–19 mm long, glabrous; ovary 0.9–1 mm long, glabrous. Fruits globose or subglobose, 8–9 mm in diam.
