Eupatorium perfoliatum or (Common) Boneset is a common perennial plant native to the Eastern United States and Canada, with a range from Nova Scotia to Florida, as well as from Louisiana and Texas. It is easily grown in average, medium to wet soils in full sun to part shade and does well in both sandy and clay soils. Needs constant moisture.
This species is a large, pubescent, clump-forming, native perennial which typically occurs in wet soils in low woods, thickets, stream banks, meadows and prairies. Flat-topped clusters (compound corymbs) of small, fluffy, white flowers appear above the foliage in late summer to fall. Perfoliate foliage is quite distinctive: the bases of the pairs of wrinkled, opposite, lance-shaped, medium green leaves unite to surround the hairy stems (perfoliatum meaning through the foliage). Historically, boneset was commonly included in medical herb gardens and used as a folk medicine for treatment of flus, fevers, colds and a variety of other maladies. Though some authorities claim the name boneset refers to a former use of the plant to aid the healing process for broken bones, others claim that the name is in reference to the plant's use as a diaphoretic in the treatment of an 18th century influenza called break bone fever. All parts of the plant are quite toxic and bitter. Also commonly called thoroughwort. Perfoliate refers to the opposite leaves thai connect with each other at the stem (no leaf stalk, or petiole).
Ther are no serious insect or disease problems. The foliage may scorch if soils are allowed to dry out.
It has nice size and late bloom for borders, native plant gardens, wildflower gardens, cottage gardens, woodland gardens or banks of ponds or water gardens.
Adapted from: Missouri Botanic Garden