A thoroughwort worthy of the name: the stems go right through the paired leaves. The name “Boneset” refers to its supposed assistance in setting broken bones.According to the ancient Doctrine of Signatures, the all-wise Creator has embedded a secret sign in each useful herb to show us what it can be used for: in this case, the joined leaves are supposed to show us that the herb can join what has been broken. Modern scientists have concluded that the all-wise Creator wasn’t as dumb as all that and must have given us a surer way to find useful medicines, which is why we have the scientific method.
Boneset likes a wet location; this plant was growing in a roadside ditch near Cranberry, where it was blooming in late August.
Gray describes the genus and the species:
EUPATÒRIUM [Tourn.] L. THOROUGHWORT. Heads discoid, 3-many-flowered; flowers perfect. Involucre cylindrical or bell-shaped, of more than 4 bracts. Receptacle flat or conical, naked. Corolla 6-toothed. Achenes 6-angled ; pappus a single row of slender capillary barely roughish bristles. — Erect perennial herbs, often sprinkled with hitter resinous dots, with generally corymbose heads of white, bluish, or purple blossoms, appearing near the close of summer. (Dedicated to Eupator Mithridates, who is said to have used a species of the genus in medicine.)
1. EUPATORIUM proper. Receptacle flat.
Heads 8-20-flowered; involucre of 8-15 more or less imbricated and unequal bracts, the outer ones shorter; flowers white or nearly so.
Leaves sessile or nearly so, with a broad base, opposite or in threes; heads pubescent.
Leaves opposite, clasping or united at the base, long, widely spreading; heads 10-40-flowered; corymbs very compound and large.
E. perfoliàtum L. (THOROUGHWORT, BONESET.) Stem stout, 0.5-1.6 m. high, hairy; leaves lanceolate, united at the base around the stem (connateperfoliate), tapering to a slender point, serrate, very veiny, wrinkled, downy beneath, 1-2 dm. long; bracts of the involucre linear-lanceolate. — Low grounds; common and well known.