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 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.