An annual, erect herb up to 1.5(-2) m tall, stem 4-angular, glabrous to pubescent. Leaves opposite or rarely alternate towards the apex, pinnately (3-)5-9-lobed, 9-19 cm long, glabrous to densely tomentose, the segments ovate to ovate-lanceolate, the lower ones often pinnatifid, crenate-serrate or rarely lobulate-dentate, petiolate; Capitula in lax paniculate cymes, usually radiate, 5-7 mm broad, outer involucral bracts (4-)5-10(-15), (3-)4-7(-12) mm x 0.4-0.7 mm, much narrower than the inner ones; ray flowers (0-)2-5, sterile, corolla 3-6 mm long, yellow, disk flowers with yellow, 3-5.5 mm long corolla. Fruit is achene linear, 4-8-ribbed, 6-16(-20) mm long, with (2-)3-4(-5) retrorsely barbed bristles of (1-)2-4 mm long. |