Out for a run with my son and this plant brushed up against his knee. Within seconds it made small red spots and within minutes the spots turned to small bumps.

What plant is this, and more importantly is it poisonous? Any advice?

We live in Minnesota and it's currently September.

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  • 69
    Out of curiosity: in which country do you live? For me as a German it's hard to imagine that someone doesn't know stinging nettles. They're ubiquitous here, and everybody knows and avoids them. Commented Sep 15, 2021 at 7:20
  • 7
    I can't believe how quickly I got an answer and how much this blew up...all within 12 hours. This community is a treasure! And for those asking, I'm an ignorant homebody suburbanite from Minnesota :)
    – LCIII
    Commented Sep 15, 2021 at 17:14
  • Comments are not for extended discussion; this conversation has been moved to chat.
    – Willeke
    Commented Sep 17, 2021 at 19:26

3 Answers 3


Yes, it is a stinging nettle, they can cause itchy rashes and general irritaion but should subside within 24 hours.

They are actually eaten after being cooked some places, and are widely used to treat a variety of ailments as an herbal medicine, such as hay fever and osteoarthritis.

Medicinal properties

The leaves and young stems of this herbaceous plant are fitted with stinging hairs tipped with formic acid and other irritants. If touched, these needle-like hairs inject the stinging acid into the skin, triggering a burning, tingling sensation and an itchy rash. Thankfully the symptoms usually do not persist longer than 24 hours. Interestingly, the cooked plant is safe to eat and is popular is some places as a vegetable.


They are irritating but nothing to be too concerned with assuming there is no abnormal reaction or allergy.

More information on the plant and its varieties can be seen here: Urtica Dioica information

  • 12
    After a bath the bumps have gone down. Woo hoo!
    – LCIII
    Commented Sep 14, 2021 at 23:05
  • 11
    When we were children, adults always told us that getting stinged by tham was good against reumatism. Commented Sep 15, 2021 at 7:27
  • 10
    There may be a dock leaf nearby. Pick a large leaf and rub it gently on the sting. That's the folklore, anyway. See Why do nettles sting? And do dock leaves really help? Commented Sep 15, 2021 at 8:08
  • 23
    24 hours is rather an overstatement. The burning usually subsides within minutes for most people. At least with those here in Germany.
    – Philipp
    Commented Sep 15, 2021 at 8:32
  • 7
    They're generally mildly painful in spring; stronger toward the end of summer and into autumn.
    – TRiG
    Commented Sep 15, 2021 at 9:23

Stinging nettle. It's so common on almost any open patch of ground in the more temperate parts of Europe that it seems weird to see this question: I'd expect every child here to have frequent encounters with them.

Their leaves sting and inject formic acid, and the bristles on the stems are quite more thorough with the same. Brushing against them tends to deliver warning bumps (more white than red though) that wear off in about an hour. Falling into them tends to trigger the nastier bristles on the stems, usually good for several hours.

The stinging and burning action is quite basic chemistry, so I don't think that the reactions between people with allergies and others will significantly differ. Skin toughness may make a difference.

The principal remedy is stoicism and ignoring the burn until it subsides.

  • 2
    For me, and I assume many more, a remedy was taught while we were quite small. One leaf of one of several plants to be rubbed onto the sore spot. (Many plants work, even soft grass.)
    – Willeke
    Commented Sep 15, 2021 at 16:41
  • @Willeke Ahh yes, the remedy here is to rub with the Dock Leaf, which always appear to grow nearby. (A natural counterbalance in the soil, or something?)
    – PCARR
    Commented Sep 15, 2021 at 18:11
  • 13
    If you don’t know what a common plant like stinging nettle is you probably shouldn't rub another plant on your skin, as you might choose something worse…
    – Stefan
    Commented Sep 15, 2021 at 19:57
  • 12
    since the "cure" is "wait it out", placebos are perfect in this case. Telling a kid "you have to deal with it until it goes away on its own" will result in a MUCH unhappier child than "here, put this (harmless! and easy to recognize for the kid, so it doesn't use something bad in the future!) stuff on it"
    – Syndic
    Commented Sep 16, 2021 at 8:42
  • 2
    For us (as kids), the cure was the sap(?) of Lamium_album - since it looks a lot like stinging nettle minus the stinging parts, it made perfect sense to us as kids. Plus, we liked the plant already because you can suck sweet nectar out of its flowers.
    – Syndic
    Commented Sep 16, 2021 at 8:45

As others have already mentioned, it's a stinging nettle.

The hairs that deliver the sting into your skin are actually not very strong, and they mostly reside on the underside of the leaves. There's a saying "if you grasp the nettle firmly, it will not sting you", and this comes from the fact that if you choose to harvest a nettle, by grasping it in a smooth motion to use the topside of the leaves to protect you as you grip the stem to pull up the plant, you can avoid being stung.

There's herbal extracts you can get that include nettle, I've also consumed it in a tea (and it had quite a unique, yet pleasant taste). I have heard of it being used as a flavour ingredient in soup also.

The stings do indeed ease after about a day, but they can be quite painful and one can cause more pain overall by scratching them as they are intensely itchy. In my personal experience, once stung, it is important to ensure that you've removed all the stinging hairs from yourself and your clothes or they will continue to sting. As a child I was always advised to apply wet mud to the stings and let it dry in order to ease the pain and itching - it did seem to work.

  • +1 But a whole day? Sure they weren't triffids? Commented Sep 17, 2021 at 2:05
  • In my book harvesting nettle is done by pinching the top 5cm of the stem. Not uprooting the whole plant as the lower leaves are old and not tasty (also why kill it).
    – Vorac
    Commented Sep 21, 2021 at 14:46
  • 1
    @Vorac When I was a kid we weren't harvesting them, we were trying to remove them to grow vegetables.
    – James D
    Commented Sep 21, 2021 at 22:20

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