Sordariomycetes
Sordariomycetes, class of several thousand species of sac fungi in the phylum Ascomycota (kingdom Fungi). The fungi are characterized by a flask-shaped fruiting body (perithecium) that bears saclike structures (asci) and usually has a pore (ostiole) through which ascospores are discharged.
Genera responsible for plant diseases include Ophiostoma (the cause of Dutch elm disease), Gnomonia (leaf spots), Diaporthe (stem and leaf blights), Cryphonectria (chestnut blight), Claviceps (ergot of rye), and the powdery mildew fungi. Fungal genetics have been extensively studied in Neurospora and Glomerella.
The zombie-ant fungus (Ophiocordyceps unilateralis) and various other members of the genus Ophiocordyceps and Cordyceps are parasites of insects and other arthropods.