优贵马兜铃 you gui ma dou ling

?Aristolochia chuandianensis Z. L. Yang; A. gracillima Hemsley.

Herbs twining. Stems terete, glabrous. Petiole 3-4 cm, glabrous; leaf blade rounded-cordate or cordate-reniform, 3-4 × 4-5 cm, submembranous, both surfaces glabrous, veins palmate, 2-3 pairs from base, base shallowly cordate or slightly concave, sinus to 1.5 cm deep, apex acute. Flowers in axils of leafy shoots, solitary. Peduncle ascending, 0.5-1 cm, glabrous; bractlets subulate, 3-5 × 2-3 mm, inserted near base of peduncle. Calyx greenish with reddish brown limb; tube rectilinear, abaxially glabrous; utricle globose, ca. 5 mm in diam., sessile; tube ca. 5 × 2.5 mm; limb unilateral, ligulate, ovate-oblong, 0.8-1 × 0.4-0.5 cm, apex acute. Anthers elliptic, 0.3-0.4 mm. Gynostemium 6-lobed. Capsule subglobose, 1.5-2 cm in diam., dehiscing acropetally. Seeds not seen. Fl. and fr. May-Oct.

* Thickets, grasslands, shady areas; 1200-2700 m. Sichuan, Yunnan.

Aristolochia chuandianensis is included here on the basis of the protologue; further research is needed to clarify its position and status.