Corticolous and lignicolous Pyrenomycetes s.lat. (Ascomycetes) on Salix along a mid-Scandinavian transect

The pyrenomycete flora on Salix is examined along a mid-Scandinavian transect. A restricted number of Salix species and a fixed number of host individuals are examined in each of the vegetation regions in central Norway, and in two vegetation regions in north-central Sweden. This investigation addressed the unsolved problems listed in my previous study (Mathiassen 1989) and the same 29 taxa are treated. The following new species are described: Amphisphaerella erikssonii G. Mathiassen, Glyphium grisonense G. Mathiassen, Keissleriella holmiorum G. Mathiassen, Leptosphaeria to/lens G. Mathiassen, and Saccardoella kanderana G. Mathiassen. The type material has been examined for all 29 species mentioned in the study, except Bertia moriformis var. moriformis.

A dichotomous key is followed by reviews of the species in alphabetical order. A systematic survey of the investigated taxa is also given. In addition to comments on taxonomy, ecology and distribution for the different pyrenomycete species, substrate ecology and host specificity are discussed. Statistical treatment of spore measurement data form the basis for a discussion of geographical variation. Multivariate techniques (ordination) are used to investigate the relative importance of geographic (including climatic) factors and the substrate tree.