Annuals; glabrous or pubescent. Stems erect, branched distally, (2-)4-12(-16) dm, sparsely to densely hirsute basally, glabrous or glabrate distally. Basal leaves rosulate; petiole 1-10(-15) cm; blade broadly oblanceolate, oblong, or lanceolate (in outline), (2-)5-20(-35) cm × (10-)20-80(-100) mm, margins pinnatisect, pinnatifid, or runcinate; lobes (3-)4-6(-8) on each side, oblong or lanceolate, smaller than terminal lobe, margins entire, dentate, or lobed. Cauline leaves similar to basal; distalmost blade with linear to filiform lobes. Fruiting pedicels usually divaricate, rarely ascending, stout, nearly as wide as fruit, (4-)6-10(-13) mm. Flowers: sepals ascending or spreading, oblong, (cucullate), 4-6 × 1-2 mm; petals spatulate, (5-)6-8(-10) × 2.5-4 mm, claw 3.5-6 mm; filaments 2-6 mm; anthers oblong, 1.5-2.2 mm. Fruits narrowly linear, usually straight, smooth, stout, (4.5-)6-9(-12) cm × 1-2 mm; valves glabrous; ovules 90-120 per ovary; style 0.5-2 mm; stigma prominently 2-lobed. Seeds 0.8-1 × 0.5-0.6 mm. 2n = 14. Flowering Apr-Sep. Roadsides, fields, pastures, waste grounds, disturbed sites, grasslands; 0-2700 m; introduced; Greenland; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon; Alaska, Ariz., Calif., Colo., Conn., D.C., Fla., Idaho, Ill., Ind., Iowa, Kans., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Europe; w Asia; nw Africa; introduced also in South America (Argentina, Chile).

Plant: Annual; stem 30-150 cm; branches many, especially above Leaves: petioled, < 15 cm, widely lanceolate; basal, lower cauline ± pinnately lobed to 1-pinnate, lobes or leaflets ± lanceolate, dentate; upper with thread-like to linear lobes or leaflets, terminal ± = lateral INFLORESCENCE: racemes, many-flowered; bracts 0 Flowers: bisexual; sepals 4, free, ± 4 mm, erect to ± spreading, outer 2 with erect horns at tip; petals 6-8 mm, pale yellow, free, clawed; stamens generally (2,4)6, generally 4 long, 2 short; ovary 1, superior, chambers generally 2, septum membranous, connecting 2 parietal placentas, style 1, stigma simple or 2-lobed; stigma 2-lobed Fruit: capsule with 2 deciduous valves, 5-10 cm, ± 1 mm wide, linear, rigid, branch-like; beak 0; pedicel generally spreading, 4-10 mm, width ± = or > fruit width; valves prominently veined;; Seeds many, ± 1 mm, generally 1 row per chamber; margin 0; embryonic root obliquely at back of 1 cotyledon Misc: Disturbed areas, fields, roadsides; < 2500 m.; May-Jul Notes: pedicels 4-10mm, spreading-ascending; petals clawed References: J.C. Hickman, ed. The Jepson Manual. W.B. McDougal. Seed plants of Northern Arizona. USDA website.ASU specimens.