Stinging nettles (Urtica dioica) have been (carefully) foraged and eaten since ancient times.
When plucked young, they can be used as a boiled green or chorta or put in a pie, τσουκνιδόπιτα (tsouknidópita) or made into a soup, or dried as a medicinal tea. They taste a lot like spinach.
Image by Leonora (Ellie) Enking