Wingspan 27 - 34mm. The top surfaces of the wings are dark brown, but the butterfly always lands with its wings closed, showing the green undersides.
Scrubby grassland, railway embankments and hedgerows. The adults like tall bushes in sheltered positions to bask in and the caterpillars feed on bird's-foot trefoil, gorse or broom.
Status and distribution
Widespread but scattered across much of lowland Britain. Uncommon in Nottinghamshire and a recent colonist at Netherfield Lagoons.
Best time to see
April to June.