First records of Myxomycetes associated with members of the Cactaceae in Australia

Context Cacti are endemic to North and South America, but numerous species have been spread all over the world after Europeans visited the Americas. Their global spread has impacted various aspects of terrestrial ecosystems, including the distributions of succulenticolous myxomycetes. Aims In this study, we examine the association of myxomycetes (also known as plasmodial slime moulds or myxogastrids) with three introduced species of cacti in Australia. Methods Using the moist chamber culturing technique we prepared 33 cultures from dead portions of three species of cacti collected in New South Wales and Queensland. Key results Eighty-eight percent of moist chamber cultures yielded evidence of myxomycetes (either plasmodia or fruiting bodies). A total of 12 species representing six genera were recorded. Physarum compressum was the most abundant species (appearing in 20 of the 33 cultures), with species such as Perichaena depressa also relatively common. We also report the first records of Perichaena luteola in Australia. Conclusions This is the first study to investigate the assemblages of myxomycetes associated with members of the Cactaceae in Australia, and we highlight the occurrence of succulenticolous myxomycetes on the continent. Implications This study leads to a better understanding of the biogeography, distribution and ecology of succulenticolous myxomycetes. We also add a new species record for Australia.