Dogweed

Tagetes papposa Ventenant, Descr. Pl. Nouv., plate 36. 1801

Leaves 15–50 × 10–40 mm overall, ultimate lobes (7–)11–15, 5–20 × 1–3 mm, glabrous or sparsely hairy, dotted with oil-glands. Peduncles 1–5(–10) mm. Involucres 6–10 mm. Phyllaries each bearing 1–7 oil-glands. Ray laminae 1.5–2.5 × 1–2 mm. Disc corollas ca. 3 mm. Cypselae3–3.5 mm; pappi 1–3 mm. 2n = 26.

Flowering summer–fall. Grasslands, open woodlands, often ruderal, fields, along roadways; 0–2000 m; Ont.; Ariz., Ark., Calif., Colo., Ill., Ind., Iowa, Kans., Ky., La., Maine, Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.Mex., N.Y., N.Dak., Ohio, Okla., Pa., S.Dak., Tenn., Tex., Utah, Vt., W.Va., Wis., Wyo.; Mexico; Central America; introduced in South America.

Records of Dyssodia papposa from Ontario and from California, Maine, Massachusetts, New Hampshire, New York, and Vermont evidently document local, probably ephemeral, introductions. In 1837, C. W. Short noted of D. papposa on a specimen label, "This plant is so abundant, and exhales an odor so unpleasant as to sicken the traveler over the western prairies of Illinois, in autumn."