common sneezeweed, more...
Perennials, 50-130 cm. Stems 1(-7), branched distally, strongly winged, sparsely to densely hairy proximally, moderately to densely hairy distally. Leaves usually moderately to densely hairy, sometimes glabrous; basal blades (withered by flowering) lanceolate, oblanceolate, or obovate, entire or weakly lobed; proximal and mid blades obovate to oblanceolate, usually dentate or entire; distal blades oblanceolate to lanceolate, entire or dentate. Heads 5-70(-100+) per plant, in paniculiform arrays. Peduncles 3-10 cm, moderately to densely hairy. Involucres globoid, 8-20 × 8-23 mm. Phyllaries (connate proximally) moderately to densely hairy. Ray florets 8-21, pistillate, fertile; corollas yellow, 10-23 × 4-10 mm. Disc florets 200-400(-800+); corollas yellow proximally, yellow to yellow-brown distally, 2.4-4 mm, lobes 5. Cypselae 1-2 mm, sparsely to moderately hairy; pappi of 5-7 entire, aristate scales (0.5-)0.9-1.5(-1.8) mm. 2n = 32, 34, 36. Flowering (Jul-)Aug-Oct(-Nov). Roadsides, fields, along streams, ditches, seepage areas, around ponds and lakes; 20-2600 m; Alta., B.C., Man., N.W.T., Ont., Que., Sask.; Ala., Ariz., Ark., Calif., Colo., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Md., Mass., Mich., Miss., Mo., Mont., Nebr., Nev., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., S.C., Tenn., Tex., Utah, Va., Wash., W.Va., Wyo.
Plant: Perennial; stem 2-10 dm; branches few-many Leaves: mostly cauline, simple, alternate, gland-dotted; lower often with short, winged petioles; upper sessile, decurrent; blades oblanceolate to elliptic, obtuse to acute, generally ± toothed, glabrous or sparsely hairy INFLORESCENCE: primary inflorescence a head, each resembling a flower; heads several-many in a ± flat-topped cyme; peduncles 3-10 cm, short-hairy; receptacle 3-5 mm diam Flowers: Ray flowers 10-20; corollas yellow; ligules 10-25 mm, fan-shaped, generally strongly 3-lobed; Disk flowers: many; corollas 5-lobed, 3-3.5 mm, yellow throughout; anther appendages short-triangular; style branches ± truncate Fruit: achenes, 1.5-2 mm, obconic, ribbed, sparsely hairy; pappus scales awn-tipped, 1-1.5 mm Misc: Wet places; < 2000 m.