Urtica - Species Dictionary - UK and Ireland : iSpot Nature - Your place to share nature. iSpot is a website aimed at helping anyone identify anything in nature. Once you've registered, you can add an observation to the website and suggest an identification yourself or see if anyone else can identify it for you.

Natural History Museum's UK Species Inventory
Plantae, Tracheophyta, Magnoliopsida, Rosales, Urticaceae, Urtica
Urtica urens, Urtica dioica, Urtica pilulifera, Urtica flabellata, Urtica massaica, Urtica incisa