Doctor of Philosophy
Dr. R. Greg Thorn
Cyphelloid fungi are, compared to their gilled relatives, poorly studied and understood. Within the tribe Resupinateae (which includes the genera Resupinatus, Stigmatolemma, Aphyllotus and Stromatocyphella), little is known about the evolution of the cyphelloid fruit body form. How many times has this reduced morphology evolved within the group? Do all cyphelloid members that are currently treated in this group belong there? Are there other described species of cyphelloid fungi currently treated in other genera that belong within the Resupinateae? This study presents phylogenies of the cyphelloid and small lamellate members of the Resupinateae based on rDNA sequences to illustrate the evolution of reduced basidiomata. This study also provides an analysis of traditional morphological characters used to distinguish species (fruit body colour and size, and spore size, shape, ornamentation and colour) and compares morphological and DNA-based classifications to illustrate a common problem in cyphelloid taxonomy: because these forms are so rarely studied, the incidence of synonymy within the group is high. The few herbarium specimens associated with many species names may lead to false impressions of host specificity or restricted geographic ranges for species that are more generalist or cosmopolitan. Some previously suggested synonymies and reports are based on misidentifications and mask genuine patterns of hosts and geographic range. Based on the phylogenetic analysis of the group, all members of the Resupinateae fall into a single genus, Resupinatus, (Stigmatolemma and Stromatocyphella are synonyms), whereas the genus Aphyllotus is excluded. This study highlights the significance of herbaria as repositories of unknown and undocumented biodiversity, and shows that the evolution of different fruit body morphologies in the Fungi is not a linear pattern of simple to complex.
McDonald, Jennifer, "Morphological and Molecular Systematics of Resupinatus (Basidiomycota)" (2015). Electronic Thesis and Dissertation Repository. 3135.