Leaf blades 8.5–29 × 4.5–16.7 cm, ovate, broadly elliptic or oblong-elliptic, obtuse to shortly acuminate at apex, cuneate to truncate or less often cordate, and frequently unequal at the base, subcoriaceous, slightly shiny above, pale (light olive-green when dry) beneath; midrib flat or narrowly crested above, prominent beneath; lateral nerves in (8)9–10 main pairs; tertiary nerves rather coarsely reticulate, often raised on both surfaces; domatia obscure; petiole 0.5–1.3 cm long; stipules 0.9–3.3 × 0.4–1.4 cm, ovate to triangular, acute to acuminate, mid-nerve not apparent.
Inflorescence a moderately lax 10–30-flowered cyme (becoming lax in fruiting stage); peduncle short, exceeded by the stipule; pedicels 3–8 mm long; bracts/bracteoles inconspicuous, ± subulate at tip.
Corolla tube 3.4–13.6 cm long and 1.5–2.5 mm wide at the top; lobes 10–26 × 1.5–5 mm, oblong or narrowly obovate, acute to acuminate.
Calyx glabrous; tube 2–3 mm long, ovate; limb-tube 1–2.5 mm long, wider than the tube; lobes filiform to subulate, 1–4 mm long.
Glabrous shrub or small tree (1.6)2–8.4 m tall; young stems ± terete.
Fruit pale green, 1.8–4 cm long, obovoid; calyx limb caducous.
Seeds pale brown, 5 mm long, with obvious striations.
Anthers almost entirely exserted, apiculate, hastate.
Pollen presenter 1.75–4 mm long, ellipsoid.