Corticioid fungi comprise a molecularly diverse, paraphyletic assemblage of species that are highly variable in their ecological functions and geographic distributions. However, due to the inconspicuous “crust-like” appearance of these species, they are easily overlooked. Furthermore, the corticioid morphology is thought to be the ancestral state of all mushroom-forming fungi, but little is known about broader evolutionary patterns of corticioid diversity, morphology, and ecology. Clarifying taxonomic and evolutionary relationships across and within corticioid lineages is necessary to recognize species diversity and enable study of their ecological roles, which range from decomposer to pathogen to plant mutualist.

One corticioid genus of particular interest is Tomentella , which is among the most diverse and abundant fungal lineages in ectotrophic forests from the boreal zone to the tropics. I am currently using a combination of type studies, high-throughput sequencing of herbarium specimens, and publicly available sequence data from ecological studies to create the first comprehensive phylogeny of tomentelloid fungi to infer global species richness patterns and test hypotheses about the geographic origin and subsequent diversification of this lineage.