Alternaria Black Mold

Macroscopic Appearance A rapidly growing rich gray black to blackish mycelium. Alternaria first appears as scattered blackish spots in the spawn jars, soon spreading and overwhelming The mushroom mycelium. On agar, it resembles a black Penicillium- ke mold. 

Microscopic Characteristics Vertically oriented lengths of cells (hyphae) emerging from a mat of mycelium that segregates into conidia, and which originated through pores at the apices of vertically oriented hyphae. Conidia (spores) are usually multicelled, sometimes Two celled and large, measuring 20-100 X 6-30 microns. 

History, Use and/or Medical Implications Species in This genus causing allergies and oTher respiratory ailments in humans, particularly hay-fever. Because of their large size, Alternaria spores soon settle, falling at a rate of 3 millimeters/second in still air. 

Comments A black mold, occasional to common on enriched agar, easily separated from similarly colored molds by its unique conidia (spores). It has been claimed thatAlternaria more frequently contaminates sorghum than rye although the authors can not corroborate this statement from their experiences. 

Class Fungi Imperfecti Order Moni tales Family Eurotiaceae 

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