Wingspan 60 - 74mm. The males are bright yellow and the females a slightly duller, greener colour, with points on the fore and hind-wings. Normally close their wings on landing.
Woodlands and woodland edge, hedgerows, gardens and railway embankments. The adult males patrol looking for rivals and females. Both sexes feed on nectar but seem to spend most of their time on the wing. The caterpillars feed on alder buckthorn and buckthorn.
Status and distribution
Common and widespread in England, less common in Wales and absent from Scotland. Common in Nottinghamshire and at Netherfield Lagoons.
Best time to see
March to May and June to September in one brood.