Size: 0.85 - 1.25 inch wingspan
Key ID features: Male bright blue above with narrow dark wing borders and white fringes. Female brown above with some blue scaling inwardly, and vague or no orange zigzag along trailing margin. Both sexes have distinct black cell end bars on FW above. Male blue-gray below with black spots and marginal row of black triangles. Female below brownish-gray with bold black spots, and orange edges to submarginal black spots on HW. HW below usually has two closely spaced black triangles edged with orange at anal angle of wing.
Similar species: Boisduval's blues have black spots below with substantial white halos, and lack orange edged triangles at anal angle of HW.
Hostplant: Several clover species (Trifolium).
Habitat: Wet meadows and riparian areas with clover.
Range: Irregular distribution pattern, in Cascades, Ochocos, Blues, Wallowas, Siskiyous, Klamaths and Warner Mtns, plus disjunct populations along the south and middle coast.
Season: Late April to late August
Abundance: Common inland, scarce along coast
Conservation Status: coastal subspecies imperiled in Oregon.