Perennials, 30-100+ cm. Stems (from short caudices) single or multiple, branched at or near bases, pubescent throughout. Leaves usually opposite (distal sometimes alternate); sessile or subsessile; blades 3-nerved distal to bases, oblong to lance-oblong, 20-45 × 5-10 mm, bases cuneate, margins entire or serrate (teeth mostly proximal), apices acute, faces finely puberulent, gland-dotted. Heads in corymbiform arrays. Phyllaries 8-10 in 1-2 series, lanceolate (tapering toward apices), 2-5 × 0.5-1 mm, apices rounded to acute, abaxial faces puberulent, gland-dotted. Florets 5; corollas 3-3.5 mm. Cypselae 2.5-3 mm; pappi of 30-40 bristles 3-5 mm. 2n = 20, 30, 40.

Flowering Jul-Sep. Dry, sandy soils, pine and oak woods, old fields; 20-100+ m; Ala., Del., Fla., Ga., Miss., N.C., S.C., Tex.

Plants treated here as Eupatorium linearifolium were long treated under the name E. cuneifolium; the latter name was superfluous when published (K. N. Gandhi and R. D. Thomas 1991). Because there appears to be a continuous range of variation between diploids that were referred to by V. I. Sullivan (1972) as E. cuneifolium and the series of putative hybrids (with E. hyssopifolium suggested as the other parent) that she called E. linearifolium, these are combined here. The tendency for the plants to branch at or near the bases is distinctive within Eupatorium.

Stems 3-10 dm, ±clustered on a crown or caudex, commonly branched at or near the ground-level, copiously provided with short, mostly loosely spreading hairs; lvs opposite, or the upper alternate, tending to be broadest above the middle, oblanceolate to obovate or nearly elliptic, tapering to the base, few-toothed or entire, triplinerved, 2-5 cm נ5-18 mm, glandular-punctate, often less hairy than the stem, the axillary shoots of the middle and lower ones commonly elongating into slender, mostly sterile branches with reduced lvs; invol 4-7 mm, coarsely villous-puberulent and atomiferous-glandular, its bracts imbricate, broadly rounded to acute, the inner inconspicuously scarious-margined; fls 5; cor white, 3-5 mm; 2n=20, 30, 40. Pine and oak woods, mostly in dry, sandy soil or in sand-hills; se. Va. to c. Fla. and w. to Miss. Aug., Sept. Triploids with oblanceolate lvs ca 5 mm wide may reflect hybridization with E. hyssopifolium. E. tortifolium Chapm. and E. linearifolium Walter (as used by Fernald) may be such hybrids.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.