Went to Malham on Saturday, and picked a bit of what I thought was lemon balm (the herb). It smelt right - very citrusy and tangy - and was absolutely everywhere. However, on returning home and consulting the web, I don't think it is lemon balm after all, as the edges of the leaves are smooth, not crinkly, and the leaves themselves are slightly furry.
It looks just like this photo:
http://en.wikipedia.org/wiki/Image:Melissa_officinalis3.JPG except for non crinkly leaves, and some of the plants had purple flowers.
Anyone know what it is? And if it's edible/drinkable (in herbal tea)? It was literally covering the ground (on the path up to the right wing), so not like I was removing part of the SSSI, heaven forbid :S