The genus Centris contains circa 250 species of large apid bees occurring in the Neotropical and Nearctic realms, from Kansas to Argentina.

Most females of these bees possess adaptations for carrying floral oils rather than (or in addition to) pollen or nectar.

They are commonly encountered bees in American deserts, and are active at very high ambient temperatures when many other species are in hiding.

They can often be seen in large numbers on desert-willow (Chilopsis) and palo verde (Parkinsonia) blossoms.

The mating system of one species, C. pallida, has been particularly well-researched by the behavioral ecologist John Alcock; the entomologist Adolpho Ducke also studied this genus.