Annuals (biennials), 20-55 cm. Stems erect, stramineous, glabrous. Cauline leaf blades obovate or oblong to spatulate, (5-)10-15(-30) mm, lengths 2-2.5(-5) times widths, bases ± clasping, margins crenate (teeth usually 7-9, sometimes 3-6, per cm, rounded to blunt, usually resin-tipped), apices obtuse to acute, faces glabrous, moderately gland-dotted. Heads in open, paniculiform arrays or borne singly. Involucres broadly urceolate, 7-10 × 8-16 mm. Phyllaries in 4-5 series, reflexed to spreading, ± lanceolate, apices recurved to nearly straight, subulate to acuminate, moderately to strongly resinous. Ray florets 20-30; laminae 7-9 mm. Cypselae brown, 1.5-3 mm, apices smooth or coronate, faces rugose; pappi of 2-3 straight, smooth or barbellulate (distally dilated), setiform awns 4-6 mm, shorter than or nearly equaling disc corollas. 2n = 12 (Mexico).
Flowering (Apr-)Jun-Sep. Moist places, plains, valleys, fields; 800-1600 m; Tex.; Mexico (Chihuahua, Coahuila, Durango, San Luis Potosí, Zacatecas).