Water hemlock is one of the most toxic plants in the United States. Sometimes confused with parsnips, even several bites of water hemlock can kill a human. The roots are particularly toxic at all times, but the leaves do lose some toxicity when they dry. Read on to learn how to identify water hemlock.
Look out for hemlock in wet or damp areas like swamps, wet fields and along streams. The plant generally grows from three to six feet tall and it is a perennial.
Recognize the plant species which resemble water hemlock to help prevent accidentally ingesting this toxic plant. Water parsnip, wild carrot (Queen Anne's lace) and other members of the parsley family look similar to water hemlock. Take care when handling any species which may be water hemlock.
Watch for plants with a purple tinged stem. Many water hemlock plants will have this coloring, but don't rely on this identification alone. The color may be mottled or a solid color. They are usually smooth, stout and hallow.
Examine the leaves and flowers. Water hemlock flowers are small and white. Each flower has five petals and five stamens. The petals also have notched tips. Leaves are alternate compound and have pointed leaflets. The veins in the leaf end at the notches between the teeth. Sometimes the leaves are tinged red.
Dig up the roots carefully so as not to release any of the toxins into water or other nearby areas. Carefully split the root. Horizontal chambers where the stem joins the root identify the plant as water hemlock. Do this extremely carefully as the poison could enter the bloodstream from an open cut or wound on the body. Wear protective clothing and wash your hands and body off immediately if you choose to handle water hemlock.