Stinging Nettle

Look closely, this is Stinging Nettle. Apparently this little plant packs a itchy, nasty, horrible punch.
When not being mowed down this plant can grow between 3 and 7 feet high, but "dies down to the ground" during the winter - whatever that means.
It has long, thin, pointy leaves that are 1-6 inches long with finely pointed serrated edges; they grow in opposite pairs that alternate e.g. a North and South pair then an East and West pair. Both the leaves and stems are covered with stinging hairs
The flowers are greenish-brownish, are very small, and grow in small clumps along smaller stems that grow from next to the leaf's base.

A good word of advice is, don't touch it bare-handed. You can eat it though, but you must either cook it or dry it completely in order to not poison yourself with it.