Phacelia, genus of 150 species of white to blue or purple-flowering annual herbs, native to North America and Andean South America and including several species of garden flowers. It belongs to the family Boraginaceae. Phacelia campanularia, native to dry slopes of southern California, bears blue, five-lobed blooms in loose sprays over the dark green, toothed, oval leaves on plants about 23 cm (9 inches) tall. From similar areas the closely related California bluebell, or wild Canterbury bell (P. whitlavia), has urn-shaped blooms.