Beware of Dangerous Carrots - U of I Extension

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Beware of Dangerous Carrots

This article was originally published on June 5, 2018 and expired on July 25, 2018. It is provided here for archival purposes and may contain dated information.

Carrots are a favorite root vegetable of children and adults alike. This delicious carrot comes in many colors and sizes, but unfortunately, the carrot family has a number of dangerous, poisonous plants in it too.

Two types of hemlock are stomach poisons when eaten. Poison hemlock (Conium maculatum) is not native to Illinois and was added to the Illinois Exotic Weed list in 2015. It grows four to nine feet tall with four to six-inch white flowers. It has a purple spotted, waxy stems. This plant is common along roadsides and ditches and has a disagreeable “mousy” odor. The entire plant is poisonous if ingested.

Water hemlock (Cicuta maculate) is considered by many to be the most poisonous plant in the northern temperate zone. Only a small amount of the toxic substance in the plant is needed to produce poisoning in animals or in humans. This native plant grows three to six foot tall with 6-inch white flowers and purple-streaked stout stems. All parts of this plant are poisonous, especially the roots.

The next three dangerous carrots cause photo-dermatitis. Cow parsnip, wild parsnip, and giant hogweed contain an allergen that is activated by sunlight to cause a rash, blisters, or other skin irritations in susceptible people.

Cow Parsnip (Heracleum maximum) is a native plant that can reach eight feet tall. Like the hemlocks, its flowers are white, but cow parsnip flowers are larger, growing to 10 inches across.

Wild Parsnip (Pastinaca sativa) has large yellow flowers that are about five inches across. It is a stout plant that grows to five feet tall with grooves along its stem.

Giant hogweed (Heracleum mantegazzianum) is the worst of the three that cause blisters in the sun. This plant lives up to its name as a giant. It grows 15 feet tall with five-foot leaves and 2 ½ foot white umbel flowers. Its massive size makes it desirable to some home gardeners, but it is a public hazard that causes severe skin irritation in susceptible people. A USDA pamphlet says this plant’s sap produces painful, burning blisters that later develop dark scars that may persist for years. Fortunately, it has only been found in an isolated location in northwest Illinois, and those plants have been eradicated. Giant hogweed is a federal noxious weed, making it unlawful to propagate, sell or transport this plant in the United States.

Finally, not all carrots are dangerous. Queen Anne’s Lace (Daucus carota) is also called wild carrot due to its large, edible taproot. It grows four foot tall with lacy four-inch flowers. This plant is the ancestor of our cultivated carrot, though its roots are white instead of orange.

More information on growing carrots and other edibles is found on the University of Illinois Extension vegetable gardening website at

Source: Rhonda J. Ferree, Extension Educator, Horticulture,

Pull date: July 25, 2018