Morphological and molecular characterization of Langdonia walkerae sp. nov. infecting Aristida stricta and A. beyrichiana in longleaf pine-grassland ecosystems in the southeastern USA

A smut fungus that hinders wiregrass restoration efforts in longleaf pine-grassland ecosystems was collected from Aristida stricta and A. beyrichiana (Poaceae) in three states in the southeastern USA. Morphological and phylogenetic characteristics of this fungus were examined. These data show that the specimens from both plant species were infected by the same fungus and represent a new species of Langdonia. The new species differs morphologically from other species of Langdonia by teliospores being solitary and not compacted into spore balls. Spore wall ornamentation and teliospore size also differ from other Langdonia species. Phylogenetic analyses of DNA sequences of the ITS, LSU, and EF-1α supported separation of the species from A. stricta and A. beyrichiana from other Langdonia species. Based on these results, a new species, Langdonia walkerae, is proposed.

A new smut fungus on a new grass: Sporisorium capillipedii-alpini (Ustilaginales) sp. nov. infecting Capillipedium alpinum (Poaceae) sp. nov., from Sichuan, China

A new smut fungus, Sporisorium capillipedii-alpini (Ustilaginales), and a new species of grass, Capillipedium alpinum (Poaceae), on which it is growing, are described and illustrated. The collections were made in western Sichuan, China. Capillipedium alpinum differs from other species of Capillipedium by its diminutive size and short, slender inflorescence. Sporisorium capillipedii-alpini is compared with the species of Sporisorium with similar symptoms (destroying all spikelets of an inflorescence) that infect Capillipedium, Botriochloa, and Dichanthium. The new smut fungus differs from these species as follows: from Sporisorium taianum by having larger spores with minutely echinulate spore walls, from S. dichanthicola by having larger spores, from S. sahayae by having lower spore wall ornamentation and thinner spore walls, from S. andropogonis-annulati by having larger spores, and smaller sterile cells with thinner walls, and from S. mysorense by possessing minutely echinulate spore walls and differently colored spores and sterile cells. The types of S. andropogonis-annulati, S. mysorense, and S. sahayae were re-examined and detailed descriptions of these species are given. A key to the smut fungi of Sporisorium, that infect Capillipedium, Botriochloa, and Dichanthium and destroy all spikelets of the inflorescence of an infected plant, is also provided.

Spore wall ontogeny in Pseudoplectania nigrella and Plectania nannfeldtii (Ascomycotina, Pezizales)

Pseudoplectania and Plectania currently belong to the Sarcosomataceae, tribe Sarcosomateae, a group with members lacking cyanophilic spore markings (absorbing a blue stain). The two genera are morphologically similar in having blackish discoid-shaped apothecia but differ in having globose and ellipsoid spores, respectively. Ultrastructural studies show that ascospores of Pseudoplectania nigrella (Pers. ex Fr.) Fuckel lack a secondary wall layer. On the contrary, Plectania nannfeldtii Korf has secondary spore wall ornamentation that is cyanophilic under a light microscope. The data suggest retention of Pseudoplectania nigrella in the Sarcosomateae; however, the position of certain species of Plectania needs to be reevaluated. Key words: Pezizales, Plectania, Pseudoplectania, Sarcosomataceae, spore ontogeny, ultrastructure.

The rusts (Uredinales) of arctic Canada

Fifty-three taxa in 11 genera are described and illustrated from the Canadian Arctic. Included are a key to the genera and keys to the species within each genus. Prior records in many journals mostly lacked illustrations. Herein light microscope photographs are complemented by SEM photographs to show spore wall ornamentation, an essential character in species delimitation.