Poison Weeds Every Gardener Needs To Be Familiar With

I found the following at the OSU website. I had been hearing more and more about poison hemlock and how people confuse it with Queen Anne's Lace. The consequences of getting this on your skin is worse than poison ivy.

Poison-hemlock

Poison-hemlock is acutely toxic to people and animals. Unrelated to the native evergreen hemlock tree, poison-hemlock can be deadly; it has gained notoriety through its use in the state execution of Socrates.
Poison-hemlock can be confused with wild carrot (Daucus carota, or Queen Anne's Lace), as with many other members of the parsley family that resemble it. It has hairless hollow stalks with purple blotches. It can get quite tall, sometimes up to 8 feet or higher. It produces many umbrella-shaped flower clusters in an open and branching inflorescense. In contrast, wild carrot has one dense flower cluster on a narrow, hairy stem, usually with one purple flower in the center of the flower cluster, and is usually 3 feet tall or less. Poison-hemlock starts growing in the spring time, producing flowers in late spring, while wild carrot produces flowers later in the summer.

Toxicity

Poison-hemlock is acutely toxic to people and animals, with symptoms appearing 20 minutes to three hours after ingestion.  All parts of the plant are poisonous and even the dead canes remain toxic for up to three years.  The amount of toxin varies and tends to be higher in sunny areas.  Eating the plant is the main danger, but it is also toxic to the skin and respiratory system.  When digging or mowing large amounts of poison-hemlock, it is best to wear gloves and a mask or take frequent breaks to avoid becoming ill.  One individual had a severe reaction after pulling plants on a hot day because the toxins were absorbed into her skin.  The typical symptoms for humans include dilation of the pupils, dizziness, and trembling followed by slowing of the heartbeat, paralysis of the central nervous system, muscle paralysis, and death due to respiratory failure.  For animals, symptoms include nervous trembling, salivation, lack of coordination, pupil dilation, rapid weak pulse, respiratory paralysis, coma, and sometimes death.  For both people and animals, quick treatment can reverse the harm and typically there aren’t noticeable aftereffects. If you suspect poisoning from this plant, call for help immediately because the toxins are fast-acting – for people, call poison-control at 1-800-222-1222 or for animals, call your veterinarian.