Plectronidium australiense is a species of fungus. Known only from Australia, where it grows on the dead branches of Banksia canei, it was described as new to science in 1986. Its conidia have a basal appendage and measure 19âÂÂ26 by 1.5 ümâÂÂshorter and narrower than the similar species P. minor, P. sinense, or P. magnoliae.