Aristolochia engleriana O.C.Schmidt

Small to moderately high twiner. Old stem subterete or slightly flattened, 8-10 mm ø, shallowly furrowed. Branches terete, 1.5-2.5 mm ø, rather smooth, shortly hairy when young, glabrescent. Leaves subcoriaceous or chartaceous, lanceolate, ovate-elliptic, obovate to oblanceolate, (5-) 8-15 (-19) by (2-) 4.5-6 (-7) cm; apex acuminate, cuspidate; base obtuse, rounded, cuneate, or broadly truncate; glabrous above, sparsely minutely hairy on midrib, nerves and veins below, glabrescent; nerves elevated beneath, distinct above; basal nerves 1 pair, ascending to ⅓-¾ of the blade; lateral nerves 2-5 pairs, sometimes hardly distinct from veins; loosely reticulate or crossbar-like veins slightly elevated beneath, often faint above; petiole terete, 5-25 (-35) mm, shortly hairy. Inflorescences in the axils of leaves, or cauligerous, spiciform, rachides up to c. 4 cm long, internodes distinct, shortly hairy; bracts minute, densely hairy. Pedicel and ovary 15-20 mm. Perianth almost straight except the slightly curved tube, whitish with violet-brown venation, or orange yellow (but tube light purplish red with scattered white spots), longitudinal veins visible or distinct, reticulations loose, obscure, shortly hairy outside, glandular-hairy inside, with a contraction between perianth and ovary; utricle obovoid or ellipsoid, c. 15 by 7 mm, no glandular bodies seen; tube 15-20 mm long, narrowed at basal part (c. 2.5 mm ø), the rest c. 6 mm ø; limb 3-lobed, lobes triangular, 5-6 by 8-10 mm, obtuse or retuse (no tail-like appendage seen). Stamens 6; anthers oblong, c. 1.5 mm. Gynostemium c. 3.5 mm long, with a distinct stipe-like part (c. 1 mm); style 6-lobed; lobes lanceolate, c. 2 mm long, no annular ring at the base. Capsule bright orange, ellipsoid, or pyriform (type description), 6-9.5 by 2-4.5 cm, 6-ridged, smooth. Seeds triangular, c. 11 by 9 mm, smooth on both surfaces, not winged.

Low montane or montane, sometimes mossy forests, (1260-) 1830-2250 m, once at 600-700 m (Mt Bosavi). Fl. March, Sept.; fr. Jan., Sept., Oct.