Species concepts in Geoglossomycetes
V. P. HUSTAD (1), A. N. Miller (2). (1) University of Illinois, Champaign, IL, U.S.A.; (2) Illinois Natural History Survey, Champaign, IL, U.S.A.
The class Geoglossomycetes (Ascomycota), commonly referred to as earth tongues, is currently comprised of one family (Geoglossaceae) and six genera (<i>Geoglossum</i>, <i>Glutinoglossum</i>, <i>Nothomitra</i>, <i>Sabuloglossum</i>, <i>Sarcoleotia</i>, and <i>Trichoglossum</i>). Published estimates of species diversity have been mostly local, with global estimates approaching 60 distinct species. However, more than 200 names of species, varieties, and forms have been validly published over the course of nearly three centuries of study, with many now reduced to synonymy or regarded as inaccurate. This research presents the latest results of our modern, multi-gene, species-level phylogeny of Geoglossomycetes. Maximum likelihood and Bayesian phylogenetic analyses using multi-gene sequences (ITS, LSU, MCM7, RPB1) were conducted along with analyses of morphological characters to reconcile gene trees and species trees. Species complexes in <i>Geoglossum</i> including the <i>Geoglossum barlae</i>/<i>nigritum</i>/<i>umbratile</i> complex and the <i>Geoglossum cookeanum</i>/<i>glabrum</i> complex have been identified and are discussed. Biogeographic patterns of speciation are also addressed. This study reveals cryptic speciation is common in <i>Geoglossum</i> and <i>Trichoglossum</i>.
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