Perennials, (30–) 50–80 (–120) cm (bases usually fibrous-rooted crowns, sometimes rhizomatous). Stems ascending to erect, sometimes semiscandent, puberulent (hairs minute, crisped). Leaves opposite; petioles (5–) 10–30 (–50) mm; blades usually deltate-ovate to ovate or broadly lanceolate, sometimes ovatelanceolate, 4–11 (–13) × 2.5–8 (–9) cm, bases usually rounded to truncate or obtuse, sometimes cordate, margins coarsely and doubly incised-serrate, apices usually acuminate. Heads clustered. Peduncles 1–5 mm, puberulent. Involucres 4–5 mm. Phyllaries: apices acute, abaxial faces glabrous or sparsely and finely villous. Corollas white, lobes sparsely short-villous. Cypselae glabrous.

Distribution

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• Legacy Map

N.B., N.S., Ont., Que., Sask., Ala., Ark., Conn., Del., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Mass., Md., Mich., Minn., Miss., Mo., N.C., N.Dak., N.H., N.J., N.Y., Nebr., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Va., Vt., W.Va., Wis.

Discussion

Varieties 2 (2 in the flora).

Selected References

None.

Lower Taxa

Ageratina altissima var. altissima, Ageratina altissima var. roanensis

Key

1	Phyllaries 3–5 mm, apices not cuspidate	Ageratina altissima var. altissima
1	Phyllaries 4–7 mm, apices cuspidate to acuminate	Ageratina altissima var. roanensis

"fine" is not a number.