This paper is a study of the sorediate corticolous species of Caloplaca in North and Central America with notes on similar species from other parts of the world. Of the 22 described sorediate species studied, 13 occur within the study area. The most common and widespread species in this group are C. chrysophthalma and C. microphyllina. Apothecia are often lacking on these sorediate species, in contrast to the isidiate species. A key, color photographs, and distribution maps are provided. Two new species are described as C. alaskensis and C. persimilis. Caloplaca granularis and Caloplaca ulcerosa are reported for the first time from North America. Several lectotypes are designated.