Nettle

Urtica urens - I think this might be a small nettle, rather than a stinging nettle as the leaves look quite rounded.
Loads of good uses for nettles - tea, soup, pesto, as a green veg - and apparently they are good for both gout and arthritis...
The fibers in their stems have been woven into fabric since the bronze age and were used to make uniforms for German soldiers in WW2.