Wing span: 1 5/8 - 2 1/4 inches (4.2 - 5.7 cm).(1)
Upper surface of male bright yellow with pale yellow at wing bases; wings edged by narrow black border crossed by yellow veins; cell spot small. Female yellow, sometimes white, with forewing border faded or absent. Underside of hindwing of both sexes green-gray; cell spot white with no surrounding ring.(1)
British Columbia south and east to eastern California, Arizona and New Mexico.(1)
Road edges, fields, meadows, sagebrush flats.(1)
One flight from May-August.(1)
Caterpillar hosts: Various plants in the pea family (Fabaceae) including milk vetch (Astragalus), Lupines (Lupinus), and clover (Trifolium) species.
Adult food: Nectar from flowers including blanket flower, milk vetches, and others.(1)
Males patrol open areas for females. Eggs are laid singly on top of host plant leaves, which the caterpillars eat. Late-stage caterpillars overwinter.(1)