It was originally found on the leaves of Chloris ciliata (fringed windmill grass) in Bolivia.

The lesions then develop into bright yellow spermogonial (conceptacle containing spermatia) pustules, usually on the upper leaf surfaces of the host plant.

Within about 10 days of spermogonium formation, cup-like aecia (spore reproductive structures) erupt through the lower leaf epidermis.

They appear as orange-yellow, circular, and slightly raised lesions produced on the lower leaf surfaces, bracts, green bolls and stems of cotton plants.

The first symptoms on grama grass are small, pale-brown uredinial lesions on the leaves.