Time of bloom: July to September.
Seed-time: August to October.
Range: Ontario and Ohio to Minnesota, southward to Georgia and Louisiana. Habitat: Prairies and dry woods, meadows, and pastures.
Terebinthine is the ancient word for turpentine, and the resinous juice of this and the preceding weed accounts for one of their common names. Stem stout, four to ten feet tall, smooth or nearly so, branching at the top into a loose and sprawling panicle. Leaves alternate, mostly basal, a foot or more in length and about six inches wide, thick and leathery, rough on both sides but especially so beneath, heart-shaped at base and pointed at tip, sharply toothed, with long, stout, grooved petioles. Heads numerous, two or three inches broad, with many long, yellow rays which are pistillate and fertile; disk-florets perfect but sterile; involucre hemispheric, its bracts erect, obtuse, and smooth. Achenes oblong, flat, narrowly winged, slightly notched at the top, and two-toothed.
Turning out the perennial roots with a plow in the fall is the surest method of destruction; but as it is most frequently a weed of permanent grasslands, deep cutting with sharp hoe or spud, just before the blooming season, is the next best remedy, using a handful of salt on the cut surface of the roots in order to retard their recovery.