Reclassification of Phialocephala based on conidial development

Abstract

Leptographium and Phialocephala are separated based on conidial development. In Leptographium , conidia develop by apical wall building and sympodial or percurrent proliferation of the conidiogenous cells. Phialocephala includes species with ring wall building as well as species with apical wall building development. Some species of Phialocephala with ring wall building development are distinguished by their phialides with deep set cylindrical collarettes and conidia produced in chains with points of attachment at both ends resembling those in Chalara and allied genera. These are placed in Sporendocladia . The remaining Phialocephala spp. all have apical wall building with proliferation usually resulting in well-defined, and often ornate collarettes. In most cases these are distinct from the poorly-defined collarettes often found in Leptographium spp. These Phialocephala spp. apparently comprise a heterogeneous group probably affiliated with a number of teleomorph genera. In contrast Leptographium spp. are all anamorphs of Ophiostoma .