Camissonia, sometimes commonly known as sun cup or sundrop, is a genus of annual and perennial plants in the evening primrose family Onagraceae. A total of 12 species are known, nearly all from western North America, especially in the California Floristic Province, but also one from South America. Previous circumscriptions of the genus had recognized up to 62 species before it was split among other closely related genera. The flowers generally open at dawn, and may be yellow, white, or lavender, often with darker shades at the base. They are usually cup-shaped, thus the common name.