NOMENCLATURE OF DRECHSLERA AND BIPOLARIS, GRASS PARASITES SEGREGATED FROM ‘HELMINTHOSPORIUM’

Abstract

As a result of a taxonomic study of some graminicolous fungi classed in ‘Helminthosporium’ the following conclusions concerning their nomenclature were reached. The original spelling of Helmisporium Link validated by S. F. Gray in 1821 is taken up instead of the illegitimate orthographic variant ‘Helminthosporium’ Link ex Pers. Helmisporium is restricted to the generic type and its chiefly lignicolous allies, all of which form conidia both apically and laterally on the conidiophores. The graminicolous species form conidia apically and a new apex is formed by subterminal growth. Sixteen species with cylindric conidia that germinate from all cells are included in Drechslera Ito. The lectotype, D. tritici-vulgaris (Nisikado) Ito, is designated and D. arundinis (Lév.) Ito is excluded. The generic name Bipolaris is proposed for the other major group of graminicolous species. These, like the holotype (basionym H. maydis Nisikado), form fusoid phragmospores that exhibit bipolar germination.