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Chaetosphaeriais a common saprobic pyrenomycete genus with simple, homogeneous teleomorphs and complex, diverse anamorphs. As currently circumscribed in the literature, the genus encompasses 30 species distributed in four ‘natural groups’, and includes morphological entities in 11 anamorphic genera. Species frequently have been defined primarily based on characters of the anamorphs resulting in species with almost indistinguishable teleomorphs. This study aimed to assess the value and significance of morphological characters in resolving phylogenetic relationships in Chaetosphaeriaand its allied genera. Phylogenetic relationships of 42 taxa, representing 29 species distributed in Chaetosphaeriaand five related genera, were estimated with partial sequences of the nuclear LSU rDNA and β-tubulin genes. Sequences were analyzed with maximum parsimony, maximum likelihood and Bayesian methods. Phylogenetic analyses of these two genes combined revealed two major lineages. The Chaetosphaerialineage includes 21 species possessing both typical and new sexual and asexual morphologies. The lineage contains a strongly supported monophyletic clade of 13 species and eight paraphyletic taxa; the latter includes C. innumera, the type species of the genus. The second major lineage includes groupings concordant with the morphological circumscriptions of the genera Melanochaeta, Melanopsammella, Striatosphaeria, Zignoëllaand the new genus Tainosphaeria.

Species of Suillusproduce fleshy, pored mushrooms. They are important symbiotic (ectomycorrhizal) partners of many coniferous trees. The genus includes several putative eastern Asian and eastern North American disjunct species, i.e., the S. americanus–S. sibiricusand S. decipiens–S. spragueicomplexes. Phylogenetic relationships among the groups were determined to further understand the biogeographic pattern. Analyses were based on 40 sequences of the ITS region of the nuclear ribosomal RNA tandem repeats, representing 18 distinct species/populations. Our phylogenetic analyses suggested that: (1) Chinese and United States' (U.S.) S. spragueiplus S. decipiensform a strongly supported monophyletic group, with North American S. decipiensand Chinese S. spragueibeing sister taxa; (2) S. americanus,Asian and U.S. S. sibiricus,plus S. umbonatusform a clade supported by a high bootstrap value; and (3) little ITS sequence divergence exists within the latter group compared to the S. decipiens–S. spragueiclade. Phylogenetic patterns revealed by this study imply a close phylogenetic relationship between eastern Asian and eastern North American disjunct population/species of Suillus.These fungi display relatively high host fidelity (at least to the host subgenus level), suggesting potential coevolutionary/comigratory trends.

AbstractSeveral collections of a pyrenomycete identified as Chaetosphaeriawere made from decorticated wood of twigs and branches in Costa Rica, Panama, Puerto Rico and continental USA. Discrete and continuous characters of the ascomata, asci and ascospores in these collections show that they are very similar morphologically and represent populations of the same species. However, culturing of single ascospore isolates from these collections yielded an anamorph unlike the typical phialidic anamorphs of Chaetosphaeria.This anamorph fits the description of Pleurothecium recurvatum, for which a teleomorph connection has not been yet established. Sequences of the ITS region of the nuclear ribosomal DNA of three collections from Costa Rica, Puerto Rico and USA were compared and found to be 98% similar. Parsimony and maximum likelihood analyses of sequences of the large subunit nuclear-encoded ribosomal DNA from representative taxa of eight ascomycetous orders show this ascomycete as a monophyletic group distinct from Chaetosphaeria.Statistical analyses of hypothetical trees based on the most parsimonious and the most likely trees rule out phylogenetic affinities of this pyrenomycete to Chaetosphaeria.These analyses suggest possible affinities to the Hypocreales and/or the Microascales. Based on morphology of the anamorph and analyses of ribosomal DNA sequence data, Carpoligna pleurotheciigen. et sp. nov. are described. The implications of the phylogenetic relationships of Carpolignain the practical identification of morphologically similar pyrenomycetes are discussed.