Arnaudiella eucalyptorumis described as a new saprobic Ascomycete fromEucalyptusleaf litter. Its anamorph, which developed in pure culture, is placed in a new hyphomycetous genus,Xenogliocladiopsis.Xenogliocladiopsis eucalyptorumsp.nov. is known from collections ofEucalyptusleaf litter in the Transvaal and Cape provinces of South Africa, where it appears to be specific to this substrate.Key words:Arnaudiella eucalyptorum, Ascomycetes, Dothideales,Eucalyptusleaves, hyphomycetes,Xenogliocladiopsis eucalyptorum.