Compilation
Thunbergia variabilis

Woody twiner or scandent shrub to 4 m tall; young branches quadrangular, with brownish bark, narrowly winged with the wings forming small “ears” at nodes, glabrous but for thin lines of hairs at youngest nodes, with dense tufts of brownish hairs in axils; older woody stems to 1 cm diam. Leaves pale green beneath; petiole 3–8 mm long, glabrous, with narrow undulate wings adaxially; lamina elliptic, largest 8.5–12.5≈3.5–4.5 cm, apex acuminate to cuspidate, base attenuate, margin on some or all undulate, never with a single large triangular tooth near or above middle (rarely all entire), glabrous. Flowers solitary; pedicels 4–9 cm long, glabrous, near base held in a fold created by the basal convolutions of the leaf-margin; bracteoles pale green, ovate to elliptic, 2–3.6≈1.1–1.6 cm, acute to obtuse, glabrous. Calyx rim 1–3 mm high, segments to 6 mm long, always some over 3 mm, with a few sessile glands and finely ciliate segments. Corolla limb and upper part of tube deep violet to rich purple, lower part of tube tube whitish, throat yellow; tube 4–6 cm long; lobes 2–3 cm long. Filaments 10–13 and 12–15 mm long, with scattered glands at base and apically; anthers 4–5 mm long. Capsule 2.5–3≈1.5–1.8 cm, glabrous. Seed dark brown, 7–8 mm in diameter.