Australian species of the genus 'Septoria' Sacc.: a morphotaxonomic revision

Abstract

One hundred and fourteen taxa, referred to the genus Septoria are recognised as occurring in Australia following study of all available collections and many type studies. Eighty-one records and reports of species occurring in Australia are rejected on the basis of absence of herbarium collections, re-disposition after examination of available material or misinterpretation of literature. Six species are recognised as not belonging to the genus but in the absence of type examination have not been transferred and are kept under their current names in 'Septoria'. The recognised species occur on fifty-five plant families, the largest number occurring on the Asteraceae (twenty-two) and the Poaceae (twelve). One un-named species is regarded as a probable saprophyte, occurring on a number of plant families and associated with dead, dying or incubated leaf tissues. 'Septoria lagenophorae' is recognised as a hyperparasitic member of the genus, being closely associated mainly with rusts but occasionally other fungi. Keys to recognised species are presented for the fungi infecting several plant families including the Apiaceae, Asteraceae, Caryophyllaceae, Fabaceae, Mimosaceae and Poaceae. Teleomorphs of the genus 'Mycosphaerella' are also described and illustrated where closely associated with an anamorphic 'Septoria'. Ten species are described as new and three new combinations are proposed. Considerable variation in conidiogenesis is noted but is regarded as intrinsic to the current concept of the genus. Five groups of species are recognised based on modes of conidiogensis. The apparent variation in conidiogenesis still affords the possibility of sub-generic segregation using conidiogenesis, conidiomatal structure and teleomorph connection.