Ageratina altissima
Phytologia 19: 212. 1970.
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 ovate-lanceolate, 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
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.
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 |