Annual, erect, undershrub, glabrous or minutely pubescent; leaves, alternate, large, simple, ovate, sinuate or deeply toothed; flowers very large, white or purple, solitary, axillary or extra-axillary; calyx long, tubular, 5-10 toothed at apex; corolla purely white or white within, purple outside, funnel shaped, mouth wide, 5-toothed; stamens-5, inserted on throat, epipetalous, filaments short, equal or unequal; ovary 2 or spuriously 4-locular, ovules 1 to many in each locule, style filiform, glabrous, stigma 2-fid; capsule deeply 4-valved, globose or subglobose, glabrous; seeds many, circular-reniform, compressed.