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A Look at Poison Hemlock

Poison Hemlock, which has been designated as a class B noxious weed in Pennsylvania, has been spotted in our area.

“It’s one of the most deadly plants in the world.”

That’s what Heidi Mullendore, an Environmental Educational Specialist at Canoe Creek State Park, said about the toxic plant.

“It’s becoming a big concern. It’s incredibly toxic to people, and it’s also very toxic to wildlife.”

Mullendore describes the plant as having a white, lacey flower on top.

(The poison hemlock we’re showing in our video is at the end of its flowering cycle so the flower is a brown color.)

Poison hemlock has a spotted, purple, hairless, hollow stem and thin, fern-like leaves.

“This plant grows in very dense colonies where its feet can stay wet. So, in wet ditches, lake edges, etc. So, it’s becoming a real problem. It’s spreading quickly and making very dense patches,”

She said the plant was brought to the United States from Europe as an ornamental flower.

It’s often confused with its “good cousin,” Queen Anne’s Lace, which also has a white, lacey flower.

“This is the plant that people generally confuse with poison hemlock: Queen Anne’s Lace, or wild carrot.”

Both are in the carrot family, so if you pull the plants out of the ground, you’ll see a carrot root covered in soil.

Because of poison hemlock’s toxic properties from the roots to the seeds Mullendore said you can die from eating it.

“When you have “carrot” in the name, people want to try it. A lot of people are into wild edibles — or talk about when grandfather or grandmother picked this or that — and think wild carrot is edible.”

She says to handle the plant with gloves, because the sap could create a poison ivy type rash on your skin.

If you don’t know what it is, don’t try it or handle it.

“It doesn’t take much to kill a 1,600-pound cow. So, you can imagine a 200-pound human. Only a few bites of seeds or roots would kill you,” Mullendore said.

Last month, an Ohio man spent over 40 days on a ventilator after handling poison hemlock.

The poison weed has ended up in people’s yards after aggressively spreading far and wide.

“Climate change is driving a lot of things on this planet. One of them is the ability for invasive species to spread and be even more invasive. This is spreading along roadways where vehicles travel, because the cars and tractors have the seeds on it,” Mullendore said.

She said the weed hasn’t made its way into Canoe Creek State Park yet.

State agencies are trying to prevent its growth while hoping for an end to the spread.

“If you think it’s poison hemlock, just leave it alone and don’t touch it. Better safe than sorry.”



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