Community Agriculture Alliance: Pretty, white flower or dangerous, poisonous plant? |

Community Agriculture Alliance: Pretty, white flower or dangerous, poisonous plant?

Community Ag Alliance

This is a year in which several members of the Apiaceae, or parsley, family of plants are doing really well and growing in abundance in our area. One has to be careful, however, when trying to identify these plants, because, while they look alike, making the wrong identification can have disastrous results.

The least problematic of these lacy, white-flowered plants is commonly referred to as cow parsnip, known by its Latin name of Heracleum lanatum. Cow parsnip has very large leaves, and the flat-topped, white flowers can spread more than a foot in width. It can be a real addition to gardens and to flower arrangements, but even though it isn’t as dangerous as the next few plants, beware —it does present challenges of its own: The plant secretes a fluid which, when on the skin, can cause a photosensitivity that leads to a harmful sunburn or rash to those who are susceptible. To avoid this issue, always wear pants, long-sleeved shirts, gloves and other protection to keep this fluid off your skin. Be cautious when using a string trimmer around this plant, as well, as the fluid can spray onto exposed skin, resulting in issues, even if the plant, itself, hasn’t been touched.

Queen Anne’s lace, or Daucus carota, is another beautiful plant, but it will cause skin issues, too. Having a carrot-like leaf, with short, coarse hairs and a root that is edible early in its growth, this plant can also be confused with poison hemlock (discussed below), so use extreme caution when making identifications. The plant is widespread and can be found in the entirety of the Continental U.S. The blooms are a collection of many smaller, flat-topped flowers arranged in such a way that they appear as larger, flat-topped flowers. The plant is found in dry pastures, disturbed areas and along roadways. It produces many seeds, so it spreads all too easily and can be invasive.

Poison hemlock, or Conium maculatum, has a well-earned name, as you can guess. Similar in growth patterns to the two above-mentioned plants, poison hemlock has leaves similar to Queen Anne’s lace but without the hairs. The flowers appear in white clusters of flat-topped blossoms but are loosely arranged and branch off the main stem. One of the most distinguishing characteristics is that the stem is smooth, with no hairs, and it typically has purple spots. The plant — all parts of it — is hazardous and should be handled with caution.

Western water hemlock and spotted water hemlock — Cicuta douglasii and Circuta maculate, respectively — are the most dangerous of these types of plants we see in Routt County. As the name indicates, this plant prefers moist areas in wetlands and along streams. Flowers appear similar to poison hemlock, with lacy clusters of small flowers branching from the main stem.

One of the best identifying characteristics of water hemlock is that the root is segmented into chambers, which hold an oily juice that is extremely toxic. This liquid can be present in the stem, as well, so anyone working with this plant needs to wear protective clothing, including safety goggles and gloves.

Mechanical removal of any of the above-mentioned undesirable plants is the best way to control them, but care are should be taken to protect all parts of your body when doing to. Be sure to remove all parts of the plant, including the root. Dispose of the plants by sending them to the landfill or burning them — never compost the plants or leave them in a place where animals or humans can access them. Herbicides can be effective but can also make the plants more palatable to animals, increasing the risk of poisoning.

If you have inadvertently come into contact with any of these plants without protective gear, immediately wash exposed body parts. If burns have resulted due to contact with the oils on the plants, seek medical attention and treat them as you would other severe skin burns. If any part of a hemlock of any variety is consumed, call a poison control center immediately, and seek medical attention right away.

With the abundance of these plants in our area this year, it is critical to know which one you have on your property and how to deal with it. There have been several recent cases, both locally and nationally, of people having been harmed by these and similar plants. Don’t be a statistic: Do your homework, and take the necessary precautions to be safe this summer.

Todd Hagenbuch is extension agent, agriculture, for Colorado State University Extension.

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