Perennial, densely hirtellous, 30-50 cm. Stems erect, simple or branched, ridged. Leaves 4-10(-11) x 2-8 cm., petiolate, triangular to ovate, hastate-auriculate with ovate and obtuse auricles and with deep sinus at base, obtuse or acute at apex. Bracts leaf-like. Pedicels shorter than flowers, deflexed. Flowers 4-7 cm., solitary. Perianth greenish-yellow, hirtellous outside; tube strongly curved, with ovoid utricle; limb oblong-triangular, cordate with 2 auricles at base, upper surface glabrous with blackish-purple spots on yellowish ground colour. Capsule 3.5-5 cm., oblong-pyriform. Fl. March-May.