Satyrium fuliginosum fuliginosum

Common Name
Sooty Gossamer-Wing

This is interpreted as the entity occurring on Castle Peak and on a tiny area of Donner Pass. It is larger and darker than subspecies semiluna, and the males lack a stigma. Males perch territorially,often on the matted ecotype of Bitterbrush (Purshia) growing along the ridgetop between Basin and Castle Peaks. Females walk a lot. Both sexes often visit Mule's Ears (Wyethia mollis) flowers, as well as Sulphur Flower (Eriogonum umbellatum). One flight in the second half of the alpine season, generally July-September. At Donner often in June, and disappearing quickly (presumably because the colony is so small). Host plants, perennial species of Lupinus, including L. arbustus and L. albicaulis.