Conium maculatum, commonly known as poison hemlock, is native to Europe and North Africa but has naturalized across temperate regions of the world, including the Americas. It is a tall biennial herb highly toxic, containing piperidine alkaloids such as coniine, which affect the nervous system. Ingestion, even in small amounts, can be fatal to humans and livestock. Historically, it's infamously known for its use in ancient Greece as a means of execution; Socrates met his end by consuming a drink made from its extracts. The plant produces umbrella-like clusters of small white flowers arranged in compound umbels, and its stems are hollow with distinctive purple blotches. Its ability to spread quickly and colonize disturbed areas has made it a common but dangerous weed in many regions. Photographed in Peru.
Photographed in Colombia and Peru.