Eupatorium bruneri A. Gray in A. Gray et al., Syn. Fl. N. Amer. 1(2): 96. 1884; Eupatoriadelphus maculatus (Linnaeus) R. M. King & H. Robinson var. bruneri (A. Gray) R. M. King & H. Robinson; Eupatorium atromontanum A. Nelson; E. maculatum Linnaeus subsp. bruneri (A. Gray) G. W. Douglas; E. maculatum var. bruneri (A. Gray) Breitung; E. purpureum Linnaeus var. bruneri (A. Gray) B. L. Robinson; E. rydbergii Britton; E. trifoliatum Linnaeus var. bruneri (A. Gray) Farwell

Plants 60–150 cm. Stems densely puberulent throughout (glabrescent at bases). Leaves: petioles pubescent to glabrescent; blades lance-elliptic to lanceolate or lance-ovate, usually 6–17 × 1.5–5(–7) cm, relatively firm, bases gradually or abruptly narrowed, abaxial faces densely hairy (hairs relatively short, spreading); distalmost whorls of leaves directly subtending heads, not surpassing heads. Phyllaries mostly glabrescent, outer sometimes densely pubescent.

Flowering summer–fall. Stream and canal banks, wet meadows, bogs, and seeps, calcareous soils; 200–2500 m; Alta., B.C., Man., Ont., Sask.; Ariz., Colo., Idaho, Iowa, Kans., Mich., Minn., Mo., Nebr., N.Mex., N.Dak., S.Dak., Utah, Wash., Wis., Wyo.