Morphology and phylogenetics of Stomatisora, including Stomatisora psychotriicola sp. nov.

Abstract

The morphology of the type specimen of Stomatisora geophilicola, the only species of the genus Stomatisora (Pucciniales) recognised till now, was restudied. Thin-walled probasidia (teliospores) develop exclusively in substomatal chambers, and mature metabasidia emerge through the stomata and develop suprastomatally. Uredinia are erumpent through the upper epidermis. A new species, S. psychotriicola, parasitizing Psychotria capensis (Rubiaceae) from South Africa, is described and illustrated. Only telia have been found which also develop in stomatal cavities, and, as in the type species, have partly repetitive probasidia and suprastomatal metabasidia that easily detach from fragile stalks. The similarities of telial morphology, as well as the same host family, indicate a close relationship and a generic separation from other rust genera. Molecular data support this interpretation and a possible relationship within a phakopsoroid clade.