Poison hemlock is an erect biennial weed that is native to Europe. The plant typically grows 4 to 8 feet tall and has smooth, hollow stems that are rigid and have distinct purple spots. The plant has shiny green leaves that are pinnately compound, multi-stemmed, and have a fern-like appearance. The leaves are lacy, resembling parsley, and have a musty odor when crushed. The first year the plant usually forms a large rosette. The second year the plant bolts a large stem, flowers, and then dies. The flowers have 5 petals, clawed, notched (1 to 1.5 mm long), and are white, umbrella-like clusters at the end of the branch. They appear from June to July. The fruit matures in August-September and is flat, small, and grayish-green in color.