Using phylogenetic species recognition to delimit species boundaries within Lasiosphaeria.

The genus Lasiosphaeria recently has been circumscribed more narrowly to include five mor-phospecies united by tomentose ascomata containing yellow centrum pigments. Species boundaries have not been established and phylogenetic relationships have not been clearly defined for these morphospecies. To delimit species boundaries and determine phylogenetic relationships among species, maximum parsimony, maximum likelihood and Bayesian analyses were conducted on sequence data from four nuclear genes, the ribosomal internal transcribed spacer (ITS) region, 28S large subunit (LSU) rDNA, β-tubulin and ribosomal polymerase II subunit 2 (RPB2). Representatives of L. glabrata, L. ovina, L. rugulosa and L. sorbina resolved as four highly supported monophyletic groups in almost all analyses and are recognized as well-defined species employing principles of genealogical concordance. These species delimitations are corroborated further by morphology. Representatives of L. lanuginosa were polyphyletic in almost all analyses. Although molecular analyses revealed that this morphospecies comprises several phylogenetic species, formal taxonomic recognition of these lineages is premature, so L. lanuginosa currently is treated as a morphological species complex. Complete species descriptions, including teleomorph, anamorph and culture characteristics, are given for L. glabrata, L. ovina, L. sorbina and the L. lanuginosa species complex along with detailed discussions of significant morphological characters used in recognizing species. These species are compared to five additional morphospecies that also may belong in the genus.