STUDIES IN HETEROBASIDIOMYCETES .140. THE USTOMYCOTA - AN INVENTORY

A recent paper by R. T. Moore proposes to include all simple septate b asidiomycetes, except the rusts, in the Ustomycota. No evidence was fo und for Moore's concept of the Ustomycota, for the dichotomy between t he simple septate basidiomycetes (excluding the rusts) on the one hand and the rusts and the complex septate basidiomycetes on the other, fo r Moore's differentiation between the Agaricostilbales and Atractiella les, for the inclusion of the Chionosphaeraceae, Pachnocybaceae and Ca mptobasidiaceae in the Atractiellales, for the erection of the family Camptobasidiaceae, for Moore's concept of the Platygloeales, for the i nclusion of the Atractogloeaceae in the Septobasidiales, for the dicho tomy of the TiIletiales between the Tilletiaceae and Doassansiaceae, f or the tripartite classification of the Ustilaginales into the Ustilag inaceae, Microbotryaceae and Tilletiariaceae. The ustomycete terms are misleading. Among the life cycle features ascribed by Moore to the us tosporic Ustomycetes is a diplophase with mitotic nuclear divisions of the diploid nucleus between karyogamy in the teliospore and meiosis i n the metabasidium; this diplophase is not documented. Sufficient data indicate that the Atractiellales contain only Atractiella, Phleogena, Helicogloea and Saccoblastia. The inclusion of Camptobasidium in the Atractiellales is inconsistent with Moore's concept of the Atractiella les. The diagnosis of the Atractiellaceae is also applicable for the C hionosphaeraceae. We disagree with Moore's description of the basidios pores of Exobasidium. The species of Exobasidium have ballistosporic b asidiospores. The Graphiolales produce holobasidia in chains. Moore's interpretations concerning the Graphiolales are also inconsistent with his definitions of the ustomycete terms. Mycoyrinx differs significan tly from the Graphiolales. We do not know valid descriptions of the Sp oridiales and Sporidiaceae. Bauhinus is regarded as a synonym of Micro botryum. It is evident from the existing data that the species of Schr oeteria are ascomycetous.