This species is a typical member of the genus. Both genders typically have pale yellow wings above with no traces of orange, unlike its close cousin the
orange sulphur which may also be yellowish. Males have clean borders, while females have yellow dots within this region. Females sometimes exhibit a white form known as
alba. The underside of the male's wings is yellow while the female's is yellow or greenish white, and both have a doubled
hindwing spot trimmed in brownish red. The hindwings show a series of four small red spots along the outer third portion, a trait that distinguishes the other North American species such as
Colias interior, with exception of the orange sulphur which also shows them. Its wingspan is 32 to 54 mm. ; Form
alba This species has white form
alba which can be very common in some populations, while rare in others. It can be confused with other white forms of
Colias particularly that of
Colias eurytheme. It can often be distinguished by the border pattern of both wings, though some individuals are impossible to separate without the presence of other "normal" specimens. Though they differ in flight style, the white forms of
Colias may be confused with other pierids such as
Pieris rapae and
Pontia protodice. White form males are also known, but they are exceedingly rare in this species. == Habitat ==