Annuals, 10-25(-50) cm. Leaves: petioles 5-40 mm (usually hispido-ciliate); blades rounded-deltate overall, 15-50+ × 12-40+ mm, 1-2-pinnatisect, ultimate lobes ovate or lanceolate to linear, 3-25+ × (1-)2-3(-15) mm, bases ± cuneate, ultimate margins entire, ciliolate, apices acute to attenuate, faces glabrous or hirtellous. Heads usually borne singly, sometimes in open, ± corymbiform arrays. Peduncles (10-)30-80+ mm. Calyculi of 3-4(-6) ± appressed, subulate to filiform bractlets 1-3 mm, margins ciliolate, abaxial faces usually glabrous. Involucres ± cylindric, 2-3(-4+) × 1.5-2+ mm. Phyllaries 4-5(-7), oblong to lanceolate, (2-)3-4+ mm. Ray florets 0 or 2-3; laminae yellowish or whitish, 1-3 mm. Disc florets 5-13; corollas yellowish to whitish, 1.5-2 mm. Cypselae: outer red-brown, flat or unequally 4-angled, linear, 6-8 mm, margins not ciliate, apices somewhat attenuate, faces obscurely 2-grooved, antrorsely hispidulous toward tips; inner similar, blackish (sometimes with pale tips), ± equally 4-angled, linear-fusiform, 9-14 mm, margins not ciliate, apices attenuate, faces 2-grooved, antrorsely hispidulous (at least distally); pappi of 2(-3), erect, retrorsely barbed awns 1-3 mm. Flowering Sep. Along streams; 900-1800 m; Ariz., N.Mex., Tex.; Mexico (Baja California, Chihuahua).
Plant: Annual forb to 50 cm Leaves: lower leaves opposite, entire to dissected; Flowers: heads rather elongate, long pedunculate; ray flowers small or vestigial, disk flowers yellow; achene black, pappus of two retrorsely hispid awns.