Annual or short-living perennial, stem 30-80 cm., much branched,. Leaves 1-5 x 0.5-3.5 cm., ovate or rhombic, irregularly sinuate-dentate or lobed. Inflorescence leafy. Valves 2-5 mm., rhomboid, acute and connate to their half, slightly thickened and irregularly toothed in the upper part. Seeds 1-1.7 mm., yellow-brown and reddish. Fl. March-November.