'Urtification' is beating yourself with stinging nettles. Roman soldiers in Britain (who introduced nettles to Britain by bringing their seeds with them)
Journal of Ecology 2009, 97, 1436–1458
Biological Flora of the British Isles: Urtica dioica L.
The high latitudinal and altitudinal ranges of U. dioica are consistent with the evidence that it survived the last glaciation and possibly earlier ones in the British Isles.