There are two species known commonly as hemlock: Conium maculatum and Tsuga canadensis. Conium maculatum is a weedy plant. All parts of the plant are poisonous. In ancient times minimal doses of the plant were used to relieve pain with a great risk of poisoning. Conium maculatum was used to carry out the death sentence in ancient times. The Greek philosopher Socrates was condemned to death by drinking a potion made from hemlock. It should not be confused with Tsuga canadensis, a member of the evergreen family. The leaves of the Tsuga canadensis may be used to make tea.