The Acmon blue is a North American butterfly. It ranges mainly in California but can be seen north to Oregon and south through Baja California. The tops of the wings are blue with dark edges in males and brown in females. Underside is white with blacks spots for both sexes with a red-orange band on the hindwing. Adult feed on nectar while caterpillars can feed on buckwheats, lupines, trefoils, and milkvetches.