Description from Flora of China
Aristolochia longifolia Champion ex Bentham, Hooker’s J. Bot. Kew Gard. Misc. 6: 116. 1854, not Roxburgh (1832), nor Sessé y Lacasta & Mociño (1894), nor (Chamisso) Hauman (1923); A. compressicaulis Z. L. Yang.
Shrubs climbing. Stems terete, striate, densely yellow-brown villous. Petiole 1-2 cm, densely villous; leaf blade lanceolate to elliptic-lanceolate or linear-lanceolate, 15-30 × 2-5 cm, leathery, abaxially densely brown villous, adaxially villous along veins, veins pinnate, 6-15 pairs, base rounded to shallowly cordate, sinus less than 0.2 cm deep, apex narrowly acuminate. Racemes on old woody stems, 2-5-flowered. Pedicel 3-4 cm, pendulous, brown villous; bractlets lanceolate-ovate, ca. 10 × 5 mm. Calyx yellow-green, limb reddish purple, 10-12 cm; tube geniculately curved, abaxially villous; basal portion of tube 50-70 × ca. 15 mm; limb discoid, 4-6 cm in diam., 3-lobed, adaxially papillate; lobes broadly rounded, slightly unequal. Anthers oblong, ca. 3 mm. Gynostemium 3-lobed. Capsule ellipsoid, 6-8 × ca. 3 cm, dehiscing basipetally. Seeds ovoid, ca. 5 × 3 mm. Fl. Jun-Jul, fr. Sep-Nov.
* Dense forests in valleys; 500-900 m. Guangdong, Guangxi, Guizhou, Sichuan.