They are known as "stinging nettles" and found in many areas in North America. You can find them right in this area, but be warned as they are called stinging nettles for a reason.

We were fishing and I thought something bit me and then after my friend starting feeling the same "stinging" sensation we knew it was nettles. As soon as I heard the word I dreaded it instantly. Yes I had been stung by these things before and way worse then this time. So I should have known. A lot of folks spend time outdoors and encounter these without even knowing it.

But why do they hurt you? Well according to

The plants contain long, thin, hollow hairs that cover the majority of the stem and the underside of the leaves. Nettle stings contain acid (formic acid) but they also contain histamine and other chemicals. The exact details are still unknown but it is the histamine that causes the initial reaction when you are stung.

This lady actually made soup from Nettles in Idaho!

I did find out there are actually some health benefits to these nettles. You can also tell in these videos what they may look like to be able to stay away or in the picture at the top.