Shrubs climbing. Branchlets brown to grayish brown, slightly angled, glabrous, with sparse, curved prickles. Leaves simple; petiole 1.5–3 cm, glabrous, with sparse, curved prickles; stipules lanceolate, 6–8 mm, glabrous; blade narrowly obovate, 7–12 × 4–6 cm, lateral veins 7 or 8 pairs, abaxially glabrous, adaxially glabrous except slightly pubescent along veins, base subcordate, margin unevenly coarsely sharply serrate to doubly serrate, apex acuminate. Inflorescence terminal or axillary, 1-flowered. Pedicel ca. 1 cm, glabrous. Flowers ca. 2 cm in diam. Calyx abaxially glabrous; sepals triangular-lanceolate, 1–1.5 cm, margin slightly tomentose, apex acuminate to caudate. Petals red, obovate, 7–8 × 6–7 mm, glabrous or basally puberulous. Stamens shorter than petals; filaments linear. Pistils many; soft hairy apically on apex of ovary and basally on style. Fruit unknown. Fl. Apr–May.