Janie - UK native stinging nettles are urtica dioica (Perennial) and the smaller, annual, urtica urens, which is a common weed in ploughed fields. The annual has considerbly fewer stings on its leaves and stem compared with the perennial.
We also have an assortment of Dead Nettles. Completely unrelated to the stingng ones, but with leaves that look almost identical. White dead nettle often grows in similar locations to the perenial, but the white flowers are a dead giveaway.
Quack
GtD.