5. Thunbergia alata Bojer ex Sims, Bot. Mag. 52: t. 2591. 1825.
翼叶山牵牛 yi ye shan qian niu
Vines, herbaceous. Stems ± 4-angled to flattened, bisulcate, pubescent. Petiole 1.5-3 cm, winged, sparsely pubescent; leaf blade sagittate to deltoid ovate, 2-7.5 × 2-6 cm, abaxially hirsute, adaxially sparsely strigose, palmately 5-veined, base hastate to cordate, margin entire or undulate, apex acute. Flowers axillary, solitary; peduncle 2.5-3 cm, sparsely strigose; bracteoles ovate, 1.5-1.8 × 1-1.4 cm, abaxially hirsute, 5-7-veined, apex acute, acuminate, or obtuse. Calyx annular, unequally 10-13-lobed. Corolla orange with dark purple glandular "eye" in throat, 2.5-4.5 cm; tube basally cylindric for 2-4 mm, throat 1-1.5 cm; lobes obovate, apically truncate. Staminal filaments ca. 4 mm, glabrous; anther thecae 3.5-4 mm, unequal, pubescent at margin and base. Ovary glabrous; style ca. 8 mm, glabrous; stigma funnel-shaped, unequally 2-lobed, lower lobe spreading, upper lobe erect. Capsule pubescent, basal part ca. 7 × 10 mm, 2-seeded; beak ca. 1.4 cm, ca. 3 mm wide at base. Seeds reticulate on dorsal surface. Fl. Oct-Mar, fr. Feb-May. 2n = 18.
Cultivated in gardens and naturalized along roads. Guangdong, Yunnan [native to Africa].
Thunbergia alata is widely cultivated and naturalized in tropical regions.