Plants annual, 60-70 cm tall, subglabrous. Stem erect, branched. Leaves alternate, sessile or shortly petiolate; petiole 2-4 cm, without basal glands; leaf blade pale green abaxially, green adaxially, broadly ovate-lanceolate or elliptic, 5-15 × 2.5-4.5 cm, rigidly papery, lateral veins 5-8 pairs, base gradually attenuate into petiole, margin serrate or crenate-serrate, apex acuminate. Inflorescences in upper leaf axils, 2-flowered; peduncles erect, 5-10 cm, slender, glabrous or puberulent. Pedicels 1-2 cm, slightly elongate at fruiting, bracteate at base; bracts caducous, lanceolate, 2-3 mm. Flowers purple-red, large, ca. 3 × 2 cm. Lateral sepals 2, green, ovate, 6-8 mm, 3-5-veined, apex acuminate, abaxial midvein thickened. Lower sepal cornute, 3-4 cm deep, narrowed into an incurved or erect spur; mouth oblique, tip mucronulate. Upper petal orbicular, 1.3-1.7 cm wide, base deeply cordate, apex retuse, abaxial midvein thickened, carinate, sometimes with a small sac or cornute; lateral united petals not clawed, 2-2.5 cm, 2-lobed; basal lobes orbicular; distal lobes dolabriform, large; auricle linear, elongate, inserted into spur. Filaments very short, broad; anthers acute. Ovary erect, fusiform. Capsule striate, linear, 2.5-3 cm. Seeds many, brown, oblong, ca. 4 mm, smooth. Fl. Aug-Sep.
Home