Rosellinia and related genera in New Zealand

Specimens labelled as Rosellinia (Xylariaceae) collected in New Zealand from the herbarium PDD were examined and could be identified as belonging to species of the genera Astrocystis, Helicogermslita, Rosellinia, and Stilbohypoxylon. One new species each of Astrocystis and Stilbohypoxylon and four species of Helicogermslita, three of them as new, are described. Eighteen species of Rosellinia could be distinguished. Only two of them, R. mammoidea and R. radiciperda, are already described from New Zealand. Five taxa could be assigned to known Rosellinia species and eleven are described as new. All species are described, illustrated, and compared with similar taxa. Keys to the genera similar to Rosellinia, as well as to the species of Helicogermslita and Rosellinia, are provided. The frequency and distribution of these fungi in New Zealand and their host preferences are discussed.