1. (Conium maculatum) A perennial herb related to carrot (family Apiaceae) that grows up to 2.5 m tall, with a smooth, hollow stem that is green and usually spotted or streaked with purple, and small white flowers borne in an umbel. The plant occurs on roadsides, in rough grassland, and on disturbed ground throughout Europe and North Africa, and it has been introduced elsewhere. All parts of the plant contain alkaloids that are extremely poisonous.

2. Several species of evergreen coniferous trees in the genus Tsuga (family Pinaceae) that grow in cool temperate climates with abundant rainfall. The smell of their crushed foliage is similar to that of poison hemlock, hence the common name, but hemlock trees are not poisonous.