The clouded yellow is a butterfly of the Pieridae family and easily identifiable by the bright yellow coloring, much brighter than that of the lemon-yellow brimstone. The upper side is golden yellow with a broad black margin on all four wings. The underside has a more greenish tint to it and lacks black borders. In the center of the underside hind wing is an obvious white spot. The wingspan of the females is 4.6 to 6.0 cm, that of the males is slightly smaller.
Clouded yellows feed on a variety of leguminous plants, such as clover and lucerne [alfalfa], and less frequently on bird’s-foot-trefoil.