Botanical Source.—This plant has many common names, and in some sections is improperly called Bowman's root. It is a perennial plant, with a round, slender, erect stem, 1 or 2 feet high, generally simple and smooth. The root is yellowish, large and branching. The leaves are scattered, sessile, oblong-ovate, or linear, entire, flat or revolute at the margin, smooth in some plants, very hairy in others, verticillate and opposite in the umbel, and from 1 to 2 inches in length. The flowers are in large, terminal umbels, with a corolla-like involucre, which is large, white, and showy. The umbels are 5-rayed, supported by as many bracteal leaves; not infrequently a small axilliary branch or two arises from the sides of the stem below the umbel. The rays of the umbels are repeatedly trifid or dichotomous, each fork attended by 2 leaflets and a flower. The involucre is large, rotate, white, with 5 obtuse, petal-like segments; at the base of these divisions are 5 interior, very small, obtuse segments. Stamens 12; a great portion of the plants are wholly staminiferous. The fruit is a smooth, 3-lobed, 3-celled capsule; the cells are 1-seeded, and the seeds smooth.