Plants glabrous or glandular-pubescent distally. Stems 3-20 dm. Leaf blades obovate, 5-20 cm, margins shallowly and irregularly crenate, apex obtuse. Cymes often lax, compound, glandular-pubescent. Pedicels 0.5-2 cm. Flowers fragrant; sepals ascending, triangular-lanceolate, 4-10 mm; corolla yellow or red-orange, flask-shaped (inflated on abaxial side), tube 15-16 mm, lobes spreading, 8-10 mm.