Annual 12-60 cm or more tall. Shoots puberulous to glabrous. Leaves elliptic-ovate to oblong-ovate, 30-150 x 20-50 mm, acuminate to subacuminate, crenate to crenate-dentate; petiole up to 35 mm long, with 2 lateral sessile glands at the base. Peduncles 50-70 mm long, (1-)3-flowered. Flowers lemon yellow, spotted brown within, 24-40 mm long. Pedicel slender, with 1-2 linear-lanceolate, 3-4 mm bracteoles. Lateral sepals pubescent, ovate-suborbiculate, 5-7 x 4-7 mm, sometimes mottled brown-black. Lower sepal saccate or conical, spur 8-20 mm long, curved. Anterior petal broad, orbicular, 10-14 x 17-19 mm, crested, apex bibbed. Capsule erect, 23-35 mm long, puberulous. Seed ovoid, 2.2-2.5 mm long, rugose.