Synonyms and other taxonomic changes
Very closely related to Eurasian Pontia chloridice (Lesser Bath White) and sometimes placed as a subspecies or synonym of it. Also closely related to Eurasian Pontia daplidice / edusa (the Bath Whites).
White with black markings above and mostly green on white below. Upper front wings with subapical dark markings normally broken into two distinctly offset rectangles, forming something of a "Z" shape (same markings forming a continuous patch in other North American Pontia species). Underside always strongly patterned, with a clear white patch crossing four cells near middle of hind wings (same area of wings on other species, if green ventral pattern is present, has veins at least partially edged in greenish, yellowish, brownish, and/or blackish scaling). Also, on basal side of same white patch, in middle of wing, there are two distinct (usually connected) dark ovals (not the same in other species).
Most of western U.S., westward from western edge of Great Plains. Not in southern New Mexico or southern Arizona. Rarely encountered west of Sierra Nevada or Cascades near west coast, except mostly west of Colorado Desert in southernmost California and Baja California Norte in Mexico. Extends into interior southern British Columbia in Canada. Apparently not yet recorded from Alberta, though it comes close.
Varied, but almost always in open semi-arid to arid areas. Tends to avoid highly disturbed agricultural areas.
Multiple broods, probably at least two in north and three or more southward. Flights from as early as February to as late as November (mostly April to September or October in north). In many areas seemingly most abundant as adults in spring.