Ribes (currants and gooseberries) are telial hosts for the introduced and invasive white pine blister rust fungus, Cronartium ribicola. Knowledge of wild and introduced Ribes helps us understand the epidemiology of blister rust on its aecial hosts, white pines, and develop disease control and management strategies. Ribes differ by species in their contribution to initial establishment and subsequent intensification of blister rust. Their significance to pine infection depends on their inherent capacities to become infected and support spore production, their abundance and environmental interactions. Ribes and white pines are adapted to disturbance and frequently co-occur in forest and woodland ecosystems. Differences in light and moisture requirements affect how long various species of Ribes occupy a site. Natural or artificial selection increases rust resistance in white pines, Ribes, and other host genera; but selection also affects virulence and aggressiveness of C. ribicola. Blister rust pathosystems evolve. Local pathosystems wherein the rust and its hosts coexist with reduced damage could arise by several processes.