Lycaena phlaeas - Small Copper
Abberant form obliterata
Abberant form extensa
This is a familiar species, present everywhere I have visited. It can be extremely variable as the butterfly photos show.
The preferred food-plant locally is Sheep's Sorrel, which is visible in the photo immediately below.
The Arctic subspecies polaris, is particularly large and beautiful, with it's whitish hindwing underside, see below.
The images below are of polaris, from Arctic Norway...