Poison hemlock is a highly toxic plant native to Europe and North Africa, but it has also spread to parts of North America. It belongs to the Apiaceae family and can grow up to 10 feet tall. The plant has small white flowers arranged in umbrella-shaped clusters and feathery, fern-like leaves. All parts of the plant contain potent alkaloids, particularly coniine, which can be deadly if ingested. Historically, poison hemlock is infamous for its use in ancient Greece, where it was used to execute prisoners, including the philosopher Socrates. Symptoms of poisoning include nausea, vomiting, and respiratory failure, making it crucial to avoid contact with this dangerous plant.