Erect, glabrous, strongly aromatic annual, up to 1-2 m tall. Stems usually with many short branches. Lvs 1-pinnate, shortly petiolate; leaflets in 3-8 pairs, linear to lanceolate, 2-8 cm long, with (8)-15-40 teeth on each side, moderately covered in large, sessile, glands, especially on lower surface. Upper cauline lvs smaller than lower, with fewer leaflets and teeth. Capitula 3-7 mm diam., in dense corymbs; peduncles solid. Involucre narrow-cylindric, 8-12 × 2-3 mm, with 3-5 short teeth at apex; glands long, many, evenly distributed above and below. Ray florets 1-3-(4); ligules yellowish green or cream, 1-3 mm long. Disc florets few, green. Achenes 3-4-angled toward base, dark brown, densely clothed in short antrorse hairs, 5.5-7 × 0.7-1 mm; pappus scales free, the longest 2.5-3 mm and with minute marginal antrorse hairs.