This medium sized butterfly with a wingspan of around 5 cm is widespread and common throughout Europe except for Scotland and northern Scandinavia. The brimstone is highly mobile and can be seen in almost any habitat.
Male brimstones have bright yellow forewings, while the hind wings are a slightly lighter yellow with a greenish hue. Each wing has a small orange spot on it. The underside of the wings is a pale yellow-green color with particularly prominent veins. Females have a much less striking greenish-white color. The shape of the folded wings combines with their veined appearance and subtle coloration to resemble a yellowing leaf, giving the butterfly excellent camouflage when at rest under bramble or ivy.