title: A new species of Heliocephala from Mexico with an assessment of the systematic positions of the anamorph genera Heliocephala and Holubovaniella.
abstract: During a study of the microfungi on decaying leaves collected in México we encountered a fungus sharing features of the anamorph genera Heliocephala and Holubovaniella. This hyphomycete resembled Hol. elegans in possessing obclavate to fusiform, three-septate, rostrate phragmoconidia, but it can be distinguished by its much shorter, branched, determinate conidiophores. Unlike members of genus Heliocephala, which also possess determinant conidiophores, the phragmoconidia of this taxon are short-rostrate and have not been observed to germinate iteratively. Prompted by the discovery of this hyphomycete, we investigated the phylogenetic relationships among species of Heliocephala and Holubovaniella. Analysis of large subunit rDNA gene sequences positioned species of Heliocephala and Holubovaniella in the Dothideomycetes and identified Stomiopeltis betulae (Micropeltididaceae) as their closest relative. These results also indicated that Heliocephala and Holubovaniella are closely related taxa. Based on these findings and the similarity of the developmental and morphological characters of species of Heliocephala and Holubovaniella, we recognize these genera as synonymous and describe a new species, Heliocephala triseptata. A dichotomous key to the species of Heliocephala is provided.
authors.affiliation: Instituto de Ecología, A.C., Apdo. Postal 63, Xalapa, Veracruz, 91000 México.
authors.forename: Gabriela Heredia
authors.initials: GH
authors.lastname: Abarca
authors.forename: Rafael F Castañeda
authors.initials: RF
authors.lastname: Ruiz
authors.forename: Rosa María Arias
authors.initials: RM
authors.lastname: Mota
authors.forename: Cinthya I Becerra
authors.initials: CI
authors.lastname: Hérnandez
authors.forename: Sergio
authors.initials: S
authors.lastname: Gómez
authors.forename: Mesfin
authors.initials: M
authors.lastname: Bogale
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Untereiner
mesh_terms: D001203:Ascomycota / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification; D001483:Base Sequence; D004271:DNA, Fungal / Q000235:genetics*; D021901:DNA, Intergenic; D004275:DNA, Ribosomal / Q000235:genetics; D008800:Mexico; D010802:Phylogeny; D018515:Plant Leaves / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D004271:DNA, Fungal; D021901:DNA, Intergenic; D004275:DNA, Ribosomal