According to Flora of China, Aristolochia petelotii occurs in forests on limestone mountain slopes; at elevation of 1800-1900 m. and is found in Guangxi, S Yunnan [Vietnam]. Some young researchers of Xishuangbanna Tropical Botanical Garden (XTBG) found two individuals of Aristolochia petelotii in Mengla, Xishuangbanna, SW Yunnan. It’s possibly the first record of this plant in Xishuangbanna.

  Description

Shrubs climbing. Stems terete to slightly complanate, striate, densely yellow-brown villous. Petiole 2-4 cm, densely yellow-brown villous; leaf blade narrowly ovate, ovate-oblong, or lanceolate-ovate, 12-18 × 5-8 cm, leathery, both surfaces glabrous or villous along veins, veins pinnate, 4-6 pairs, base shallowly cordate, apex acuminate. Racemes on old woody stems, 2- or 3-flowered, 4-6 cm. Pedicel 3-4 cm, pendulous, yellow-brown villous; bractlets ovate-lanceolate, ca. 10 × ca. 5 mm. Calyx yellow with purple-brown blotches and reticulate veins; tube geniculately curved, abaxially densely villous; basal portion of tube 50-65 × 10-20 mm; limb oblong-peltate, 5-8 × 4-7 cm, 3-lobed; lobes unequal, rounded. Anthers oblong, 3-4 mm. Gynostemium 3-lobed. Capsule narrowly ellipsoid, 10-15 × 5-8 cm, dehiscing basipetally. Seeds not seen. Fl. Sep, fr. Dec.

(Source: http://foc.eflora.cn/content.aspx?TaxonId=242414709 )