Annual or short-lived spreading perennial, clammy or viscid with glandular hairs, especially on young shoots, peduncles and pedicels. Petiole short. Lamina 2-6 × 1.5-6 cm, orbicular to lanceolate; base attenuate; apex rounded to acute. Calyx 10-20 × 2-8 mm, narrow-oblong to spathulate, densely glandular-hairy, ± obtuse. Corolla c. 3.5-7 cm long; tube densely glandular-hairy outside; limb ± patent, 4-6 cm diam., white, pink, crimson, purple or violet. Capsule 6-10 mm long, ovoid. Seed 0.5-0.7 mm diam., mostly globose to oblong, strongly reticulate.