AbstractA key, descriptions and illustrations of Australian members of Ephemeraceae are provided. A new species,Ephemerum furcatumI. G. Stone is described;Ephemerum grosseciliatumC. Müll. is reduced to synonymy withEphemerum cristatum(Hook. f.&Wils.) C. Müll.; and two new Australian records,Ephemerum recurvifolium(Dicks.) Boul. andNanomitriopsis longifoliaCard. are reported.