Perennial, hirtellous-puberulent, 30-60 cm. Stems more or less erect, simple or branched, not climbing. Leaves 2.5-9 (-10) x 1.5-5 (-6) cm., ovate-oblong to lanceolate-triangular, hastate-auriculate at base with rather oblong or rounded auricles and a deep sinus, tapering towards the more or less acute apex; petiole much shorter than blade. Bracts small, leaf-like. Pedicels about as long as flowers, slender, deflexed. Flowers 4-6 cm., solitary. Perianth rusty-red with yellow spots; tube almost glabrous, strongly incurved, gradually broadening towards apex, with ovate-oblong limb hirtellous on upper spotted surface, cordate and auriculate at base. Capsule 4-6 cm., obovoid-oblong. Fl. March-May.