Acremonium: Filamentous fungi commonly isolated from plant debris and soil. May also be found in damp carpet and gypsum board. A few species of Acremonium implicated in mycetoma and keratitis.

Alternaria: Dematiaceous fungus commonly isolated from plants, soil, food, and indoor air environments. Alternaria are occasional agents of sinusitis.

Ascospores: Frequently found indoors on damp substrates. This Class consists of several different species. Majority do not cause pathogenic disease, some do exist.

Aspergillus: Filamentous, ubiquitous, fungus found in nature. Commonly isolated from soil, plant debris, and indoor air environments. The Aspergillus genus includes over 185 species. Approximately 20 species have so far been reported as causative agents of opportunistic infections in humans.

Basidiospores: Composed of a very diverse community of spores. Capable of causing “dry rot” which can destroy the wood structure of buildings. Opportunistic infections are caused only on rare occasions.

Beauveria: This hyaline, filamentous fungus first recognized as the etiologic agent of the devastating muscardine disease of the silkworm, is ubiquitous in plant debris and soil. Beauveria is also isolated from foodstuff, infected insects, and indoor air environment. Beauveria bassiana is a very rare human pathogen. It may be associated with keratitis. Pneumonia in an immunocompromised patient due to Beauveria has also been reported.

Bipolaris: Dematiaceous, filamentous fungus. Commonly isolated from plant debris and soil. Can produce Ascospores. The Bipolaris genus contains several species, with three well-known pathogenic species.

Chaetomium: Dematiaceous, filamentous fungus found in soil, air, and plant debris. Can be a contaminant, also encountered as causative agents of infections in humans. Thermophilic and neurotropic in nature. Genus contains several species.

Cladosporium: Dematiaceous mold widely distributed in air and rotten organic material and frequently isolated as a food contaminant. 

Curvularia: Dematiaceous, filamentous fungus. Most species are facultative pathogens of soil, plants, and cereals. Can be a contaminant and cause infections in humans and animals. 

Epicoccum:Dematiaceous, mitosporic mold widely distributed and commonly isolated from air, soil, and foods. Also found in some animals dander and textiles. Causative agent of leaf spots of various plants. 

Fusarium: Filamentous fungus widely found on plants and within soils of crops such as rice, bean, soybean and others. Common contaminant and well-known plant pathogen, it can cause various infections in humans.

Memnoniella: Contaminant, found most often with Stachybotrys on wet cellulose. Mainly isolated from soils and dead plant material in tropical countries but has also been isolated from indoor sources such as paper, wallpaper, and textiles. Exposure to this genus should be avoided as they can produce griseofulvins, a potentially toxic metabolite.

Mucor: Filamentous fungus found in soil, plants, decaying fruits and vegetables. Mucor is ubiquitous in nature.

Myxomycetes/Smut/Periconia:These spores are hard to differentiate from one another under microscopic analysis; therefore group together during identification. Found on decaying plants and soils. No known toxins at this time.

Nigrospora: Filamentous, dematiaceous fungus widely distributed in soil, decaying plants, and seeds. Common laboratory contaminant. 

Penicillium: A filamentous fungi that is widespread and found in soil, decaying vegetation, and air. Commonly considered contaminants but may cause infections to immunocompromised hosts. Genus contains several species.

Pithomyces: Found to be growing on paper or decaying plants. Commonly considered a contaminant, but has not been implicated in human infection. 

Rust: Must have living plant material available for them to grow. Not found indoors unless host plants are present. No known toxins at this time.

Stachybotrys: Filamentous fungus occasionally isolated as a contaminant from nature and indoor environments. Produces trichothecene mycotoxins known as satratoxins. These toxins may lead to pathological changes in animal and human tissues. Associated with “sick building syndrome” at times.

Torula: Often found growing in soil, dead herbaceous stems, wood, grasses, sugar beet root, ground nuts and oats. Grows well on general cellulose surfaces but spores may take special nutrients to develop or may be completely absent. Type I allergies (hay fever, asthma).

Ulocladium: Dematiaceous filamentous fungus that inhabits the soil and decaying plants. Widely distributed in nature and may be isolated from paper, textiles, and wood. Commonly considered a contaminant. May very rarely cause human disease. Genus contains two species.

Verticillium: Widely distributed filamentous fungus that inhabits decaying vegetation and soil. Commonly considered a contaminant. May very rarely cause human disease.  

Barnett, H.L, Hunter, B.B. Illustrated Genera of Imperfect Fungi. 4th Ed. APS Press, St. Paul, Minnesota. 1998.
Larone, D. L. Medically Important Fungi, A Guide to Identification. 4th Ed. ASM Press. Washington, D.C. 2002
Murray, P.R., Baron, J.B, Pfaller, F.C., Yolken, R. H. Manual of Clinical Microbiology. 6th Ed. ASM Press. Washington, D.C. 1995.
Wang, C.J., Abel, R.A. Identification Manual for Fungi from utility Poles in the Eastern United States. Allen Press, Inc, Lawrence, Kansas. 1990.