A color version of Plate 1. Many solitary bee pollinators of Clarkia xantiana, such as (left) Hesperapis regularis, forage exclusively on species in the genus Clarkia. These bees have specialized scopae, (middle) composed of sparse and unbranched hairs, which accommodate the (right) large and often clumped pollen grains of Clarkia. Photo credit: D. Moeller. Click here for a large image of the plate for closer viewing.