August 16, 2020 Calochortus argillosus Clay Mariposa Clay mariposa (Calochortus argillosus). Photo by Elsa de Becker.Clay mariposa lily (Calochortus argillosus).Clay mariposa lily (Calochortus argillosus), Lime Ridge Open Space, Walnut Creek. Photo by Cathy Chambers. More InformationEast Bay Calochortus: Photos, Figures, Facts, and Fun! Where to see itIn the Woods at Shell Ridge: A Photo EssayThis Spring in the East Bay: Dying Acacias and Blooming Wildflowers