Erect annual. Stems densely hairy above and sparsely to moderately hairy near base, solid, striate, 40-120-(200) cm high, sometimes purple tinged; hairs deflexed. Basal lvs moderately to densely hairy above and below, 1-2-pinnate, petiolate; utlimate segments ovate to lanceolate, pinnatifid and serrate, 10-40-(80) mm long, sessile or shortly petiolulate; stem lvs similar to basal but 1-pinnate or pinnately 3-foliolate toward apex with less divided segments. Umbels 2-5 cm diam., long-pedunculate, usually terminal; rays (2)-6-11, 10-20 mm long; bracts (2)-4-6, linear; bracteoles 4-7, linear. Fls few to numerous, pinkish or purplish white, 1-3 mm diam., irregular. Fr. ovoid, 3-4 mm long; all mericarps spinous; spines curved upward, hooked and pointed at tip.