Two species are commonly known as hemlock: Conium maculatum and Tsuga canadensis. The first is a weedy plant, and all parts of it are poisonous. In ancient times, minimal doses of the plant were used to relieve pain, although with a great risk of poisoning from this form of treatment. This hemlock was also used to carry out death sentences in ancient times; for example, the Greek Athenian philosopher Socrates (469 B.C.E.–399 B.C.E.) was condemned to death and sentenced to drink a potion made from hemlock. The poisonous species should not be confused with Tsuga canadensis, a member of the evergreen family. Its leaves are not poisonous and are often used to make tea.