When settled, the Clouded Yellow hardly ever opens its wings so normally only the underwings are seen. These are deep yellow, with a black spot halfway across the forewing. In the centre of each hindwing is a pair of silver spots surrounded by reddish brown forming a conspicuous figure-of-eight. Yellow-green eyes peer out from a yellow head and body. The butterfly is usually seen in rapid flight, thus revealing rich orange upperwings with broad black borders that cannot be confused with any other species. There is, however, a pale form of the female, called helice, in which the orange ground colour is replaced by grey. It is quite common in some years.

Dimensions:
Adult wingspan: 25-62mm.

National:
This regular migrant from the continent has been recorded throughout much of the British Isles with records predominant in the southern part of the country. The numbers recorded in the country are dependant on conditions that lead to immigration. The foodplant is varied but restricted to the Pea family, invariably clovers including introduced species.

At Durlston:
At Durlston, the species has been recorded as common in some years and has become more regular in recent years. Most records are of immigrants occurring from mid summer to early autumn. There has been no proof of breeding.

Eggs are laid singly on leguminous plants such as Lucerne Medicago sativa and cultivated clovers Trifolium spp.. The larvae produce a cocoon attached to the stem of the plant. These then hatch in the same season while later generations will overwinter as pupae. In Britain, the immigrant population in early summer often leads to a generation emerging in late summer and early autumn and, very occasionally, these produce another generation. The butterfly may overwinter as an adult if conditions are right.