What to Know About Colorado’s Increase in Poison Hemlock Observations
For the last week or two, people on my neighborhood Facebook page have been warning others about an increase in poison hemlock in their backyards. They aren’t alone - others in Colorado have noticed, too.
Photo Credit: Flickr. “Poison Hemlock.”
Poison hemlock is an invasive plant with lacy, fern-like leaves and small, white flowers. It can grow from four to eight feet tall. It is most common “along streams, rivers, irrigation, roadside ditches, crop and pasturelands and disturbed sites” (KDVR), which may explain its recent increases in abundance in Colorado Springs; the city is under significant construction due to infrastructure repairs and additional housing.
Poison hemlock is toxic and can be fatal to humans and animals; alkaloids in the plant “attack [the] nervous system and heart” when one comes into contact with the sap in any way, including by ingesting the plant (KDVR).
Why would anyone be ingesting it? Well, it has several lookalikes in the Apiaceae family (commonly known as the “carrots, parsley, and celery” family). Some are edible, but some are dangerous. To my (untrained) eye, these four plants - all found in Colorado - look very similar.
More descriptions (if using assistive technology, please click here for detailed description):
As you can tell from the photos and table above, these plants look incredibly similar, and incorrectly identifying them could have serious consequences!
So if you see a plant like this and if you’re in doubt, stay away from it - and definitely don’t eat it! If you think you have come into contact with poison hemlock or giant hogweed, call Poison Control at 1-800-222-1222.
Contact the Colorado Department of Agriculture for assistance in identifying and/ or removing toxic plants. Also see the Poison Hemlock Factsheet at the Colorado Department of Agriculture website or CSU’s Guide to Poisonous Plants.
For more information on edible vs. toxic plants, listen to “Foraging Ecology” from the Ologies podcast with host Alie Ward and expert Alexis Nikole Nelson (and search her handle @BlackForager for entertaining and informational videos about plants)!
