This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Perennial. Propagates by seeds.
Time of bloom: June to August.
Seed-time: August to October.
Range: Newfoundland to Manitoba, southward to Florida and New Mexico.
Habitat: Low grounds; wet meadows, marshy places, sides of ditches, and ponds.
Fig. 209. - Poison Hemlock (Conium maculatum). X 1/4.
Quite as poisonous as the preceding plant and probably the cause of more fatalities. Roots two to four inches long, thick, fleshy, tuberous, bunched in a cluster (fasciculated) at the swollen base of the stem. These are especially dangerous, for their taste is pleasantly aromatic, somewhat like that of its harmless relative, Sweet Cicely, for which they are sometimes mistaken, generally with fatal results; or they may be mistaken for artichokes or parsnips in the early spring. At this season the roots are frequently forced out of the earth by washing or freezing, or cattle and sheep, biting at the young shoots, pull them easily from the wet soil. One of the fascicled roots will kill a cow, and a much smaller portion, when eaten by a person, is sufficient to bring a swift and distressful death, unless medical aid is immediately at hand. (Fig. 210.) Stems stout, smooth, hollow, two to six feet tall, streaked with brown and purple, the color more pronounced at the junction of stem and branches. Leaves pinnately twice or thrice divided, the segments lance-shaped, thin, sharply and rather coarsely toothed, the veins terminating in the notches instead of at the points. Umbels open and spreading, without involucres, the pedicels in the umbellets unequal in length, giving the clusters an uneven appearance; like all the Parsley Family, the flowers are very small, five-petaled with five stamens inserted on the disk that crowns the two-celled and two-seeded ovary. In this species the petals are white. Carpels about an eighth of an inch long, ovoid, smooth, each one striped on the convex side with five corky ribs and four brown oil-tubes and on the flat side with two wide corky stripes and two oil-tubes.
Fig. 210. - Water Hemlock (Cicuta maculata). X 1/4.
Grub out and destroy the plants, allowing no seeds to ripen and fall into the soil to perpetuate so deadly a menace to the safety of the children and the domestic animals of the neighborhood. Or the plant is easily pulled, roots and all, in the spring when the ground is soft and the young shoots first appear.