hemlock

Hemlock refers to Conium maculatum, commonly known as poison hemlock, a tall biennial herb in the Apiaceae family. It has hollow, often purple-dotted stems, finely divided, lacy leaves, and large flat-topped umbels of tiny white flowers that bloom in summer. The plant can reach up to two meters in height and prefers moist, disturbed soils.

Native to Europe, parts of North Africa, and western Asia, poison hemlock has spread to many regions as a weed in fields, ditches, roadsides, and riverbanks. It readily establishes in moist environments but can tolerate a range of soils. All parts of the plant contain potent alkaloids and are highly toxic if ingested.

Toxicology and symptoms: The principal toxin is coniine, along with related alkaloids, which affect nicotinic acetylcholine receptors. Ingestion can cause numbness, dizziness, salivation, vomiting, muscle tremors, and paralysis, potentially leading to respiratory failure and death. There is no antidote; treatment is supportive, often requiring respiratory support. Handling the plant should be cautious, as contact with skin can still pose risk if pieces are ingested or inhaled smoke if burned.

Safety and identification: Poison hemlock can be confused with other toxic Apiaceae species, including water hemlock (Cicuta spp.), which is even more dangerous. Due to its high toxicity, it is not used for culinary or medicinal purposes. Historical notoriety includes its association with the execution of the philosopher Socrates. Effective management focuses on preventing seed set and avoiding ingestion by humans or livestock.