A comprehensive taxonomic study of four families of Australasian Helotiales has been conducted. Details of the taxonomy of constituent species of Geoglossaceae, Orbiliaceae, Sclerotiniaceae and Hyaloscyphaceae from this region are presented, and a description of the type genus of the type family, Leotiaceae, is given for comparative purposes. In addition, an historical survey of the collection of Australasian discomycetes is included and notes on the principal collectors given in an appendix.
The presentation of the taxonomic account takes the form of a key to the families of Helotiales occurring in Australasia, keys to the accepted genera in each included family and to the species in each genus. A full description and discussion of the nomenclatural and taxonomic status of each genus is provided and all species are fully described and illustrated. The complete synonymy of each species is given, together with a detailed discussion and comparison of related taxa.
All material relevant to the Australasian region has been examined and a total of 38 genera, 124 species and 5 infra-specific taxa are recognized. Six extra-limital species, directly relevant to the investigation of these taxa, are described and illustrated. The main taxonomic conclusions are as follows: 8 new genera (+ 1 new name), 1 new sub-generic section, 22 new species (+ 2 new names), 1 new variety, 1 new form and 45 new combinations are proposed. Within the Geoglossaceae, the conservation of Geoglossum Pets. (1796) against Geoglossum Pers. (1794) is proposed. Geoglossum Zignicolum is placed as a synonym of G. australe, G. noumeanum as a synonym of G. pumilum and G. barlae tentatively as a synonym of G. umbratile. The genus Habrostictis is referred for the first time to Orbiliaceae and Patinella is shown to be better removed from this family and placed in Dermateaceae. Orbilia auricolor is shown to be the correct name for the species long known as O. curvatispora and O. delicatula to be the earliest name for the species long known to British authors as O. xanthostigma. Torrendiella is referred for the first time to Sclerotiniaceae and shown to be the correct genus for Australasian species previously placed in Zoellneria. Lanzia rufocornea is referred to a new genus, Dicephalospora. Mollisia nothofagi is placed as a synonym of Helotium berggrenii, and this species is transferred to the genus Lanzia in Sclerotiniaceae; Helotium metrosideri is reduced to a variety of it. A new section is proposed within the genus Ciboria to accommodate lignicolous species.
The family Hyaloscyphaceae is considered to include an heterogeneous assemblage of genera and, as currently circumscribed, to be an artificial taxon. The circumscription of the subfamily units commonly employed, based on hair and subiculum characters, also suggests these to be artificial, obscuring relationships between genera. Thus, they have not been employed here. Within the Hyaloscyphaceae, Belonidium is confirmed as a synonym of Lachnum, Peziza melanopus is placed as a synonym of Lachnum brasiliense and Trichopezizella as a synonym of Lasiobelonium. Erinella novae-zealandiae is placed as a synonym of Perrotia lutea and Trichopeziza sphaerula is shown to be an earlier name for Perrotia aurea.
The Australasian Helotiales exhibit a diversity of characters not previously represented in the order. Whilst many species can be referred to long-established genera known from the northern hemisphere and now shown to have a wider distribution, it has been necessary to recognize a considerable number of new genera. These amount to c. 20% of those studied. A similar Dronortion of the recognized species were previously undescribed. Some of these species are sufficiently distinctive to serve as the types of new genera, but in no case has there been difficulty in assigning a genus to its appropriate family. It has therefore not been necessary to redefine the families in question in order to accommodate the Australasian members of the order.