Compilation
Thunbergia aurea

Erect unbranched single-stemmed annual herb; stems to 20 cm long, sparsely sericeous-pubescent. Leaves with petiole 1.5–3 cm long, with a flat wing which widens upwards, indumentum as stems; lamina triangular-ovate, largest 3.5–4.5≈1.2–2.2 cm, apex subacute, base truncate to subcordate, with subhastate lobes, margin entire or with a few teeth in lower part, sparsely sericeous-pubescent, below densest along veins, above uniformly. Flowers axillary, solitary; pedicels 1.5–3 cm long, indumentum as stems; bracteoles green, with conspicuous purple venation, ovate, 1.5–2.2≈0.6–1.3 cm, subacute, cordate and distinctly 4-angular at base, sparsely sericeous-pubescent, densest on veins and margins. Calyx puberulous with mixture of hairs and stalked capitate glands, rim ± 1 mm high, segments linear, 2–4 mm long. Corolla yellow, without purple throat; cylindric tube 3–4 mm long; throat straight, campanulate, 1–1.5 cm long and 0.7–0.8 cm in diameter apically; lobes ± 5≈5 mm, truncate to broadly emarginate. Filaments ± 5 and 6 mm long; anthers ± 2 mm long, not apiculate, bearded at base only; spurs ± 1 mm long. Capsule puberulous, depressed globose, 6–7≈8–9 mm, beak 10–11 mm long, constricted at base. Seed ± 4 mm in diameter, blackish, echinate.