Stephen Dalton / Green aphid / Greenfly (Aphidoidea) extracting sap from stem of nettle, UK

Simon Colmer / Small Tortoiseshell butterfly (Aglais urticae) close up of caterpillar, feeding on nettle leaf, Sussex, UK, June

Simon Colmer / Small Tortoiseshell butterfly (Aglais urticae) caterpillar, feeding on nettle leaf, Sussex, UK, June

Paul Harcourt Davies / Annual nettle (Urtica urens) flowers, Italy

Stephen Dalton / Close up of stinging spine of a Nettle plant {Urtica sp} Poison is visible at tip of left barb, UK

Jose B. Ruiz / Flowering Nettle {Urtica sp.} Spain

Adrian Davies / Kirlian photograph of Nettle leaf {Urtica sp}