This is a butterfly characteristic of calcareous grasslands and is widespread across much of southern England. It is rarely found in the East Midlands region, and has not been recorded since 2014.
The male is silvery-blue with black margins, including black spots on the outer edge of the hind wings, and chequered white wing fringes. The brown females can be distinguished from Common Blue females by their larger size, less prominent orange lunules and chequered white wing margins.
It is on the wing in July and August.
Eggs are laid singly on Horseshoe Vetch.