Date of Degree


Document Type


Degree Name





Roy E. Halling

Committee Members

Roy E. Halling

Amy C. Berkov

Sarah E. Bergemann

James C. Lendemer

Joseph W. Rachlin

Subject Categories

Biodiversity | Botany | Evolution | Integrative Biology | Other Ecology and Evolutionary Biology | Other Genetics and Genomics | Other Plant Sciences


mycology, phylogenetics, systematics, mushrooms, pileipellis, southern hemisphere


Gyroporus (Sclerodermatineae, Boletales, Agaricomycetes, Basidiomycota, Fungi) is a genus of ectomycorrhizal mushroom-forming fungi distributed throughout the world in suitable habitats. Previous attempts to untangle the diversity of this genus proved difficult due to the presence of semi-cryptic species and equivocal results from phylogenetic analysis of ribosomal RNA markers. To overcome these obstacles, a combined taxonomic and phylogenetic (emphasizing protein-coding genes) approach is used here to delimit species and elucidate geographic and evolutionary patterns of Gyroporus. Careful study of relevant literature and herbarium specimens was augmented by field work in North America, Australia, and East Asia for observation and collection of fresh material. For phylogenetic analyses, the mitochondrial gene atp6 and the nuclear gene rpb2 were utilized. The nuclear gene tef1 was also utilized for select exemplars.

Several distinct clades are inferred, most notably a clade corresponding to Gyroporus castaneus as a speciose northern hemisphere group (the castaneus clade), a clade unifying Gyroporus cyanescens and similar entities (the cyanescens clade), and a clade unifying Gyroporus longicystidiatus and a New World sister species (the longicystidiatus clade). Also highly notable is the recovery of a sister relationship between the cyanescens and longicystidiatus clades. Abundant sister relationships between Eurasian and North American (including Central American) Gyropori are apparent and suggestive of boreotropical biogeographic scenarios; the Australian Gyropori display various biogeographic affinities. Eighteen new Gyroporus taxa are outlined and several biogeographic hypotheses are discussed. This study provides key groundwork for future efforts on this well-known but poorly-understood group of fungi.