Annual or perennial trailing or twining herb, when perennial with single or several stems from woody rootstock; stems to 5 m long, yellowish to whitish sparsely sericeous or sericeous-pubescent to pilose or tomentose. Leaves with petiole 0.8–7(–9.5) cm long, with a flat (rarely undulate) wing which on some or all leaves widens distinctly upwards or is parallel-sided, sometimes very narrow or absent on some (more rarely all) leaves, indumentum as stems; lamina triangular or triangular-ovate, largest 2–10(–12)≈1.2–7(–8.5) cm, apex acute or subacute, apiculate, base subcordate to deeply cordate (rarely truncate) with hastate or rounded basal lobes, margin entire to coarsely dentate, sericeous-pubescent or sparsely so to tomentose, below densest along veins, above uniformly. Flowers axillary, solitary (rarely paired or in 3’s); pedicels 2–9.5(–11) cm long, indumentum as stems; bracteoles green, sometimes with purple venation or mottled with purple, ovate to oblong, (1–)1.4–3.5≈0.5–1.6(–2.1) cm, acute to rounded, truncate to cordate and distinctly 4-angular at base, whitish to yellowish pubescent or sericeous-pubescent or sparsely so, densest on veins. Calyx puberulous and with scattered to dense stalked capitate glands, rim 0.5–2 mm high, segments linear, 1–5 mm long. Corolla pale yellow to brillant orange or brick red (rarely white) with deep purple to almost black throat; cylindric tube 3–6 mm long; throat straight or slightly curved, campanulate or narrowly so, (1.2–)1.5–2.8(–3.2) cm long and 0.7–1.8 cm in diameter apically; lobes 0.8–2≈1–2.5 cm, broadly emarginate. Filaments 2–7 and 4–9 mm long; anthers 3–5 mm long, indistinctly apiculate, densely bearded at base and along 2/3 of one side; spurs 1–1.5 mm long. Capsule densely puberulous, depressed globose, 6–9≈7–12 mm, beak 8–17(–19) mm long, constricted at base. Seed 4–6 mm in diameter, dark brown, echinate-lamellate or reticulate. Fig. 8, p. 57.