Annual herbs. Stem 100-200 cm, branching, 4-angled, almost glabrous, with few hairs in the upper part, erect, often reddish above. Leaves opposite, petiolate, pinnate, with 1 pairs of leaflets. Terminal leaflet with a petiole up to 30 mm, longer than lateral leaflets. The petioles of the lateral leaflets up to 3-5 mm long. Leaflets lanceolate to oblong-lanceolate, acute or acuminate, coarsely serrate, light green below dull green above. Capitula 8-15 mm in diameter, erect, wider than long. Outer involucral bracts spreading, 6-8, herbaceous, light green, up to 30 mm long, occasionally leaf-like with a few hairs below; inner 5-9 mm, ovate-oblong, with dark brown mucronate tips, yellowish green to dirty dark yellow, glabrous. Corolla 3 mm long, whitish at base, yellowish at apex. Receptacular scales as long as achenes, lanceolate, scarious at margins. Anthers 1 mm long, purplish. Achenes compressed, up to 4-7 mm long , rugose, blackish to dark brown. Bristles of achenes 2, about 3 mm long.