A medium-large butterfly of England, Wales and Ireland. Leaf-shaped wings.

The Brimstone has spread in recent years, mainly in northern England. When this butterfly roosts among foliage, the angular shape and the strong veining of their wings closely resembles leaves.

There is a view that the word ‘butterfly’ originates from the yellow colour of male Brimstones. The wings of the female are very pale green, almost white, males have yellow-green underwings and yellow upperwings.