Technical Abstract: The summer-blooming annual forbs Cleome lutea and C. serrulata (Cleomaceae) are widespread in the U.S. Intermountain West and Rocky Mountains, respectively. Their farmed seed is sought to help rehabilitate western rangelands. This study of the reproductive biologies and pollinator faunas of C. lutea and C. serrulata is the first for their cosmopolitan family, the sister family to the Brassicaceae. Both species of Cleome were found to be self-fertile and capable of some autonomous pollination. Outcrossing enhanced neither seed set, seed viability nor seedling vigor. Large, openly visited plants yielded >20,000 seeds. Flowers of both species first shed their pollen, secreted nectar and became receptive nocturnally. However, no nocturnal visitors were found, but both Cleome species attracted diverse diurnal native bees, wasps and butterflies. Among the many floral generalists that work Cleome flowers for pollen and nectar are two managed agricultural pollinators, Apis mellifera and Megachile rotundata. These observations bode well both for pollinating C. lutea and C. serrulata in small commercial seed fields, as well as for these two species¿ value for sustaining native pollinator faunas during early stages of plant community restorations, particularly after fire.