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Plants by Scientific Name
This 2-10 feet tall herbaceous perennial or biennial native of the Umbelliferae family is very difficult to separate from other species of the same family. It has a tuberous root with 2-8 oblong tubers which are 1.5-3 inches long and about 1/2 inch thick at the thickest point near the middle and stem end. The purple-streaked stems are stout and erect with much branching. The stems are solid when very young, but become hollow with nodes where the leaflets are attached. The stems are chambered with horizontal diaphragm of pith tissue which are more closely arranged at the base of the stem. The horizontal plates of piths are most easily visible by cutting the stem base lengthwise.
The alternate leaves are pinnately 2-3 times compound. The leaves of most species are lanceolate, 2-5 inches long, and sharply toothed. The base of the ong petioles clasp the stem.
Flowers are white and tiny (no more than 1/8 inch across), have 5 petals, and appear in loose compound umbels at branch ends in mid summer. Umbels measure from 2 to 8 inches across and become somewhat spherical in fruit. Fruits are ovoid and ribbed on the outer surface.
New growth begins from tubers as well as from seeds.
White snakeroot is an erect, branched herb usually about 3 feet tall but varying from 1 to 5 feet. It has slender, round stems and branches bearing pointed, oval, oppositely placed leaves. These leaves, 3 to 5 inches long and petioled, are sharply toothed on the margins. Each leaf has 3 main veins that show prominently on the underside. The roots are fibrous, coarse, and shallow. In late summer, numerous small heads of minute white flowers appear at the top of the stem and the ends of the branches. These flower heads, except that they are white, are almost exactly like the flower heads of the familiar ageratum of gardens. Later the flowers are replaced in the heads by small black seeds each with a crown of soft white hairs. Because the leaves of white snakeroot resemble those of the nettle, other plants with nettle-like leaves are often mistaken for it. Two such plants are the nettle-leaved sage and the nettle-leaved vervain. Even without flowers or fruit, these plants can be easily distinguished from white snakeroot. The nettle-leaved sage, a rare plant in some southern Illinois counties, has square stems; white snakeroot stems are round. The nettle-leaved vervain, a common weed throughout Illinois, has lance-shaped leaves; white snakeroot leaves are broad at the base but narrow quickly in a wedge-shaped part to the petiole.
Leaves: alternate, simple, toothed. Flower: elongated custer, 5-part, white. Fruit: Black or red fleshy fruit with stone in center.