Marielliottia, a new genus of cereal and grass parasites segregated fromDrechslera

摘要

Marielliottia, a new genus of hyphomycetes, is described. Three species formerly treated inDrechsleraare included:D. biseptata, the type,D. dematioidea, andD. triseptata. The species differ fromDrechslerain having mostly three-septate, obovoid to ovoid conidia that germinate primarily from the basal cell, occasionally from the apical cell, and not from the central cells. These fungi are occasional parasites of cereals and grasses, are sometimes seed borne, and may infect nongrass plants. The type species is implicated in mycotoxicosis of sheep and produces zaragozoic acid A.Key words: mycotoxins,Helminthosporium, M. biseptata, M. dematioidea, M. triseptata.