Triteleia hyacinthina

From Oregon Flora, Gardening with Natives:

Hyacinth or white brodiaea boasts delicate umbels of bowl-shaped pale flowers having green veins and a small crown-like center. Also called Fool’s Onion, hyacinth brodiaea blooms in late spring and early summer and, when grown in large swaths, will add a soft, downy texture to woodland or meadow gardens.