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It can be difficult to determine whether you’re looking at hogweed, hemlock or parsnip, but all of these plants have several things in common. Contact may cause unpleasant, potentially deadly, reactions. We at the U.S. Fish and Wildlife Service want to help you identify and differentiate these plants so you can keep your distance as needed. Most of these plants are invasive and easily grow in ditches and disturbed soils across the country. Get familiar with these species to stay safe!
Giant hogweed
Heracleum mantegazzianum
Giant hogweed is native to Asia, but invasive in North America. Contact with giant hogweed may cause severe irritation to the skin and eyes, blistering rashes, permanent scarring and even blindness. This plant earns the title of giant, regularly reaching heights of more than six feet and sometimes reaching up to 18 feet. Stems are thick and hollow with ridges and purple spots. See where giant hogweed has been confirmed in the U.S. and Canada »
Poison hemlock
Conium maculatum
Poison hemlock is native to Europe, Africa and Asia, but invasive in North America. All parts of this plant are highly poisonous to people and animals. Ingestion of even small amounts may result in death. This plant typically measures three to eight feet tall and has stems that are hairless and hollow with ridges and purple spots. See where poison hemlock can be found »
Spotted water hemlock
Cicuta maculata
Spotted water hemlock is widespread and native to North America. Water hemlock is often called the most deadly plant in North America. All parts of this plant are highly toxic to people and animals. Ingestion may cause abdominal pain, convulsions, delirium, nausea, seizures and vomiting - often resulting in death. This plant typically measures three to six feet tall and has stems that are smooth and hollow. Stems may vary in color and pattern, from solid green or purple to green with purple spots or stripes. See where spotted water hemlock can be found »
Cow parsnip
Heracleum maximum
Cow parsnip is native to North America. It is listed as endangered in Kentucky and a species of special concern in Tennessee. Contact with cow parsnip may cause skin irritation, blistering rashes and skin discoloration. This plant can measure four to ten feet tall and has stems that are fuzzy and grooved. See where cow parsnip can be found »
Wild parsnip
Pastinaca sativa
Wild parsnip is native to Asia and Europe, but invasive in North America. Yellow flowers help differentiate this species, but the effects are similar. Contact with wild parsnip may cause skin irritation, blistering rashes and skin discoloration. This plant typically measures two to five feet tall and has stems that are hairless and grooved. See where wild parsnip can be found »
Queen Anne’s lace
Daucus carota
Queen Anne’s lace is native to Asia and Europe, but invasive in North America. If you have sensitive skin, contact with Queen Anne’s lace may cause skin irritation. Others may not experience any negative interactions. Before you consider handling this plant, make sure you're positive that it's not one of the similar-looking species listed above. This plant typically measures one to two feet tall and sometimes has a small reddish flower in the center. Stems are fuzzy with small grooves. See where Queen Anne’s lace can be found »
