Novel species of Cercospora and Pseudocercospora (Capnodiales, Mycosphaerellaceae) from Australia

•One new species of Cercospora and three new species of Pseudocercospora from Australia are described.•There is a close phylogenetic relationship between Australian species of Pseudocercospora on diverse and unrelated host plant species.•Native Australian species of Pseudocercospora may have diverged as opportunistic pathogens from a recent common ancestor.

Novel species of Cercospora and Pseudocercospora are described from Australian native plant species. These taxa are Cercospora ischaemi sp. nov. on Ischaemum australe (Poaceae); Pseudocercospora airliensis sp. nov. on Polyalthia nitidissima (Annonaceae); Pseudocercospora proiphydis sp. nov. on Proiphys amboinensis (Amaryllidaceae); and Pseudocercospora jagerae sp. nov. on Jagera pseudorhus var. pseudorhus (Sapindaceae). These species were characterised by morphology and an analysis of partial nucleotide sequence data for the three gene loci, ITS, LSU and EF-1α. Recent divergence of closely related Australian species of Pseudocercospora on native plants is proposed.