Description from Flora of China
Aristolochia roxburghiana Klotzsch.
Herbs twining. Stems terete, slightly furrowed, glabrous. Petiole 2.5-4 cm, glabrous; leaf blade ovate-cordate or oblong-ovate, 8-12(-24) × 4-14(-22) cm, papery, both surfaces glabrous, veins palmate, 3-5 pairs from base, base deeply cordate, lateral lobes subrounded, sinus 1-3 cm deep, apex acute or acuminate. Racemes in axils of leafy shoots, 2- or 3-flowered, 2-6 cm. Pedicels ca. 1 cm, sparsely hairy, glabrescent; bractlets ovate-lanceolate, to ca. 8 mm. Calyx pale yellowish or greenish, throat dark purple, 4-6 cm; tube rectilinear or slightly curved; utricle globose, 5-8 mm in diam., with stipe 1-3 mm; tube 5-10 × 2-3 mm; limb ligulate, oblong, 2-3 × 0.5-0.6 cm, apex obtuse. Anthers ovoid, ca. 1 mm. Gynostemium 6-lobed. Capsule obovoid-globose to ovoid-cylindric, 3.5-5 × 2-3.5 cm, dehiscing acropetally. Seeds triangular to subcordiform, ca. 8 × 8 mm. Fl. May-Aug, fr. Oct-Dec.
Forests, mountain slopes; below 100-2000 m. Fujian, Guangdong, Guangxi, Guizhou, Taiwan, Yunnan [Bangladesh, Bhutan, Cambodia, India, Indonesia, Japan, Nepal, Malaysia, Myanmar, Philippines, Sikkim, Thailand, Vietnam].