Perennials, (20–)30–60(–80) cm. Stems 1–3+ (ridged), erect, branched (usually glabrous proximally, puberulent distally). Leaves mainly cauline; petiolate; blades ovate to rounded-deltate, 4–10+ × 1.5–4 cm, usually 1–2-pinnately lobed (primary lobes 3–5+ pairs, ± ovate), ultimate margins pinnatifid to dentate, faces (at least abaxial) usually puberulent, gland-dotted. Heads 5–20(–30) in corymbiform arrays. Involucres 5–7 mm diam. Ray florets 10–21+ (more in “doubles”), pistillate, fertile; corollas white, laminae 2–8(–12) mm. Disc corollas ca. 2 mm. Cypselae ± columnar, 1–2 mm, 5–10-ribbed; pappi 0 or coroniform, 0.1–0.2+ mm. 2n = 18.

Phenology: Flowering Jun–Nov.
Habitat: Disturbed sites, urban areas, roadsides, fields, abandoned plantings
Elevation: 10–1900 m

Distribution

• Generated Map
• Legacy Map

B.C., Ont., Ala., Colo., Conn., Del., Idaho, Ill., Ind., Ky., Maine, Md., Mass., Mich., Miss., Mo., Mont., Nev., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., R.I., S.C., Utah, Vt., Wash., W.Va., Wis., Wyo., Eurasia, n Africa, widely naturalized in New World and Old World.

Discussion

Tanacetum parthenium is widely cultivated throughout North America.

Selected References

None.

Lower Taxa

None.