Hemlock, also known as Conium maculatum, is a highly poisonous biennial herbaceous flowering plant in the carrot family Apiaceae, native to Europe and North Africa. It is a hardy plant that can live in a variety of environments and is widely naturalized in locations outside its native range, such as parts of Australia, West Asia, and North and South America. Hemlock is toxic to humans and animals, and all parts of the plant are poisonous, including the seeds, root, stem, leaves, and fruit. Hemlock is most poisonous during the early stages of growth in the spring.

Hemlock can be confused with other plants such as wild carrot, wild parsnip, or anise, and accidental poisonings have occurred when people mistook the plant for harmless plants. Poison-hemlock has white flowers that grow in small erect clusters, and each flower develops into a green, deeply ridged fruit that contains several seeds. The plant has a white root and a hollow stem with purple splotches, and it can grow 2 to 10 feet tall. The delicate leaves of the plant look like parsley.

Hemlock is frequently found in the US and southern Canada, typically growing along streams or rivers, and near fences, roadsides, ditches, abandoned construction sites, pastures, crops, and fields. Despite serious safety concerns, hemlock is used for bronchitis, whooping cough, asthma, arthritis, and other conditions, but there is no good scientific evidence to support these uses.

In summary, hemlock is a highly poisonous biennial herbaceous flowering plant that is toxic to humans and animals. It is native to Europe and North Africa and is widely naturalized in other parts of the world. Hemlock can be confused with other plants, and accidental poisonings have occurred when people mistook the plant for harmless plants.