burn hazel burn nettle burn weed herb herbaceous perennial herbs itching leaf leaves medical plant medication medicine natural nature nettle nettles pain painful plant plants stems stinging nettle sunlight sunshine urtica dioica admiral butterflies butterfly red summer wings botanics burning flower flowers grow pattern patterns spring structure structures texture textures flora green Green leaves growth herbal sting Stinging Nettles argentina field sky homeopathy naturopathy tee annual danger frilly stinging urens Urtica young background cutout isolated no path tree white Galeopsis tetrahit hemp nettle roadside bug fly insect colour Ladybird variety