Leaf-inhabiting genera of the Gnomoniaceae, Diaporthales. 2008. (Studies in mycology, Vol. 62). illus. col. photogr. V, 79 p. gr8vo. Paper bd.

The Gnomoniaceae are characterised by ascomata that are generally immersed, solitary, without a stroma, or aggregated with a rudimentary stroma, in herbaceous plant material especially in leaves, twigs orstems, but also in bark or wood. The ascomata are black, soft-textured,thin-walled, and pseudoparenchymatous with one or more central oreccentric necks. The asci usually have a distinct apical ring. The Gnomoniaceae includes species having ascorpores that are small, mostlyless than 25 microns long, although some are longer, and range in septation from non-septate to one-septate, rarely multi-septate. Molecular studies of the Gnomoniaceae suggest that the traditionalclassification of genera based on characteristics of the ascomata suchas position of the neck and ascopores such as septation have resultedin genera that are not monophyletic. In this paper the concepts of the leaf-inhabiting genera in the Gnomoniaceae are reevaluated usingmultiple genes, specifically nrLSU, translation elongationfactor 1-alpha (tef1-a), and RNA polymerase II second largest subunit(rpb2) for 64 isolates. ITS sequences were generated for 322 isolates.Six genera of leaf-inhabiting Gnomoniaceae are defined based on placement of their type species within the multigene phylogeny. Thenew monotypic genus Ambarignomonia is established for an unusual species, A. petiolorum. A key to 59 species of leaf-inhabiting Gnomoniaceae is presented and 22 species of Gnomoniaceae are describedand illustrated.