Eupatorium pilosum


Fl. Carol., 199. 1788.

Common names: Rough boneset
Synonyms: Eupatorium rotundifolium var. saundersii (Porter ex Britton) Cronquist Eupatorium verbenifolium Michaux
Treatment appears in FNA Volume 21. Treatment on page 471. Mentioned on page 463, 464.

Perennials, 30–100+ cm. Stems (from short rhizomes) single, sparsely branched distally, densely puberulent to pilose throughout. Leaves usually opposite (distal sometimes alternate); simple, sessile or subsessile; blades ± 3-nerved (distal to bases), elliptic, lanceolate, or lance-ovate, 30–90 × 20–45 mm (lengths mostly 2–2.5 times widths), bases rounded to rounded-cuneate, margins unevenly serrate, apices acute to attenuate, faces puberulent, gland-dotted. Heads in corymbiform arrays. Phyllaries 7–10 in 2–3 series, oblong to lance-oblong, 2–7 × 1–1.5 mm, apices (sometimes whitish) acuminate to acute, mucronate, abaxial faces puberulent, gland-dotted. Florets 5; corollas 3.5–4 mm. Cypselae 3–4 mm; pappi of 30–50 bristles 4–5 mm. 2n = 20, 30, 40.

Phenology: Flowering Jul–Sep.
Habitat: Moist, low ground, margins of ponds, sandy soils, savannas, ditches
Elevation: 20–100+ m



Ala., Conn., Del., Fla., Ga., Ky., La., Md., Mass., Miss., N.J., N.Y., N.C., Pa., R.I., S.C., Tenn., Va., W.Va.


Eupatorium pilosum has been most commonly treated as a variety of E. rotundifolium; it is distinct morphologically by its leaves, which are narrower and 3-nerved distal to bases, rather than 3-nerved from bases. Distal leaves of E. pilosum tend to differ from the proximal by being alternate with entire margins.

Selected References


Lower Taxa

... more about "Eupatorium pilosum"
Kunsiri Chaw Siripun +  and Edward E. Schilling +
Walter +
Rough boneset +
Ala. +, Conn. +, Del. +, Fla. +, Ga. +, Ky. +, La. +, Md. +, Mass. +, Miss. +, N.J. +, N.Y. +, N.C. +, Pa. +, R.I. +, S.C. +, Tenn. +, Va. +  and W.Va. +
20–100+ m +
Moist, low ground, margins of ponds, sandy soils, savannas, ditches +
Flowering Jul–Sep. +
Fl. Carol., +
Eupatorium rotundifolium var. saundersii +  and Eupatorium verbenifolium +
Eupatorium pilosum +
Eupatorium +
species +