Ustilago maydis
English: Corn Ergot; Corn Smut.
Names: Uredo maydis.
German: Beulenbrand.
Clades: Ustilaginaceae; Ustilaginales; Heterobasidiomycetidae; Basidiomycetes; Fungi.
Mycology: dimorphic fungus, yeast and filamentous state; invades young host tissue, causing hypertrophy and uncontrolled cell division, hyperplasia; forms large, tumourlike, black galls; incidence higher in soils high in nitrogen; mutation common; styptic.