Ynghylch

The brimstone is a fairly large, pale yellow butterfly, with distinctive, leaf-shaped wings. Adults hibernate through cold weather, so may be seen flying on warm days throughout the year, although they are most common in the spring. Usually seen in ones or twos, they are never very common, but are widespread. They can be found in damp woodlands, along sunny, woodland rides and mature hedgerows, and in large gardens. The foodplants of the larvae are buckthorn and alder buckthorn. Both shrubs are found in wet woodland, while buckthorn also occurs on dry chalk and limestone soils.