Neonectria and Cylindrocarpon: the Nectria mammoidea group and species lacking microconidia.

Neonectria (Hypocreales: Nectriaceae) species having Cylindrocarpon anamorphs that lack microconidia and chlamydospores include: Neo. discophora var. discophora, Neo. discophora var. rubi, stat nov. et comb. nov., Neo. lucida, comb. nov., Neo. viridispora, sp. nov. and Neo. westlandica, comb. nov. Perithecia of these species are red and perithecial anatomyis of the N. mammoidea type, with a palisade of hypha-like cells in the outer perithecial wall. These species occur on recently dead or dying trees. Perithecia of Neo. betulae, sp. nov and Neo. dumontii, sp. nov. are anatomically and biologically similar to those of Neo. discophora. The only known culture of Neo. betulae remained sterile, while Neo. dumontii has not been cultured; their anamorphs are presumed to be Cylindrocarpon. Analyses of mit ssu rDNA sequences indicate that Neonectria/Cylindrocarpon is monophyletic. Within the genus, species having N. mammoidea type perithecia are paraphyletic. Most species cluster with Neo. discophora, but Neo. westlandica and Neo. trachosa are basal to a clade that includes species that do not have a N. mammoidea-type perithecium. Nectria fuckeliana clusters independently of Neonectria and Nectria. Although reported to have a Cylindrocarpon anamorph, fresh ascospore isolates of N. fuckeliana did not produce Cylindrocarpon macroconidia but produced acremonium- or verticillium-like anamorphs. A key to nectriaceous species of Neonectria that have Cylindrocarpon anamorphs that lack microconidia and chlamydospores and/or that have a N. mammoidea type perithecial wall anatomy is presented. New combinations are proposed for other species formerly included in Nectria that have non-microconidial Cylindrocarpon anamorphs: Neonectria cinnamomea, Neo. jungneri, Neo. platycephala, Neo. phaeodisca and Neo. verrucospora.