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Mold Glossary

A   |   B   |    C   |   D   |    E   |   F   |    G   |   H   |    I   |   J   |    K   |   L
M   |   N   |    O   |   P   |    Q   |   R   |    S   |   T   |    U   |   V   |    W
X   |   Y   |    Z


Acropetal: Production of conidia where the conidium at the tip of the chain is the youngest / most recently formed, and the conidium at the base of the chain is the oldest, e.g. Cladosporium.

Allergen: Any substance that causes an allergic reaction.

Allergy: Hypersensitivity of the body's immune system in response to exposure to specific substances (antigens).

Anamorph: The asexual state of the fungus life-cycle, characterized by production of conidia.

Annelations: Crosswise bands on conidia produced by repeated formation of conidia from the inner wall of the conidiogenous cell.

Annellide: Type of conidiogenous cell that extends as each conidium is formed, producing a distinctive ring-like scar at the tip.

Antigen: A substance that induces the immune system to produce antibodies.

Arthroconidium (pl. arthroconidia): A conidium that is produced by fragmentation of a hypha, e.g. Geotrichum.

Ascoma (pl. ascomata): Any structure that produces asci; synonym of ascocarp.

Ascomycetes: Group of fungi characterized by the formation of sexual spores in sac-like structures called asci.

Ascospore: Sexual spore produced in an ascus.

Ascus (pl. asci): The typically sac-like structure produced by ascomycetes in which ascospores (generally 8) are produced following sexual reproduction.

Aspergilloma: A 'fungus ball' produced by species of Aspergillus, typically without symptom.

Aspergillosis: Any disease produced by species of Aspergillus.

Asthma: Respiratory disorder characterized by wheezing; usually due to allergic response.

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Basidioma (pl. basidiomata): Any structure that produces basidia; synonym of basidiocarp.

Basidiomycetes: Group of fungi characterized by the formation of sexual spores on specialized cells called basidia.

Basidiospore: Sexual spore produced on a basidium.

Basidium (pl. basidia): A specialized cell on which basidiospores are formed on spike-like structures called sterigmata (sing. sterigma) following sexual reproduction.

Basipetal: Production of conidia where the conidium at the base of the chain is the youngest / most recently formed conidium, and the conidium at the tip of the chain is the oldest, e.g. Penicillium Aspergillus.

Black mold: A term used by the media to describe mold growing indoors which is black in color. Has no scientific significance as it can describe a number of different fungi.

Black yeast: A group of fungi that produce hyphae, and also form black, shiny colonies and yeast-like cells, e.g. Aureobasidium.

Blastic: Conidia formation characterized by a marked enlargement of a conidium before it's fully formed.

Brown rot: Type of decomposition produced by basidiomycetes where the cellulose and hemicellulose components in wood are broken down, leaving lignin unchanged, giving the wood a rusty or dark-brown color and a dry, cubical crumbly structure.

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Cellulolytic: Able to decompose cellulose-containing material.

Cellulose: The chief constituent of the cell wall in all green plants; an insoluble complex carbohydrate. Paper has high cellulose content.

Chlamydospore: A spore, usually with a thickened secondary wall, produced singly and within a hypha.

Cleistothecium: An enclosed ascoma, usually spherical, lacking a pore and releasing spores by disintegration of the ascoma wall.

Coelomycetes: A class of asexual fungi that produce conidia within enclosed structures.

Columella: Supporting structure found within sporangia of zygomycetes.

Conidiogenous cell: A specialized cell that produces conidia.

Conidiophore: A segment of hypha that bears conidiogenous cells.

Conidium (pl. conidia): Asexual spore produced through mitosis.

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Dematiaceous: Dark in color.

Denticle: A small, tooth-like projection.

Deuteromycetes: Fungi that lack the ability to produce spores through sexual reproduction. Many "molds" are deuteromycetes, producing conidia only.

Dictyospore: A spore divided by intersecting crosswalls in more than one plane.

Dimorphic: Having two forms, usually a filamentous and a yeast-like form depending on environmental factors.

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Endophthalmitis: Infection / inflammation of the interior of the eyeball.

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Filamentous: Composed of, or similar to, a filament or fine thread. For fungi, 'filamentous' refers to a growth form characterized by the abundant production of hyphae (as opposed to yeast-like).

Floccose: Cottony in texture.

Fruit body: Spore-producing organs in fungi, e.g. ascoma, basidioma, conidioma.

Fungal sinusitis: Reaction caused by fungi resulting in nasal congestion and polyps that can lead to serious disease.

Fungi: A kingdom of eukaryotic organisms with absorptive nutrition. Includes four main groups (phyla): Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota.

Fusiform: Spindle-like with narrowed ends.

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Geniculate: Bent like a knee.

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Hyaline: Transparent or colorless.

Hypha (pl. hyphae): Long, branching, tubular cell of a fungus. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.

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Immunocompromised: Unable to develop a normal immune response usually because of an underlying illness or immunosuppressive therapy.

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J, K

Keratitis: Microbial infection of the eye.

Keratomycosis: Keratitis caused by fungi.

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Lanate (pl. lanose): Wooly in texture.

Lignin: In plants, a stiffening substance that is the most abundant polymer in plant cell walls after cellulose; a complex, polymerized carbohydrate.

Lumber yard mold: Does not refer to a single species of fungus, but rather refers to a group of unrelated fungi that commonly colonize lumber, often staining the wood.

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Macroconidium: Term used to describe the larger conidium type produced by a fungus that produces two types of conidia.

Meiosis: A series of two nuclear divisions in which the number of chromosomes are reduced by one-half (from diploid - two copies of each chromosome, to haploid - one copy of each chromosome); the last phase of sexual reproduction.

Meiospore: "Sexual spore"; a haploid spore produced through meiosis.

Microconidium: Term used to describe the smaller conidium type produced by a fungus that produces two types of conidia.

Mitosis: Cellular division in which the daughter cells have the same number of chromosomes as the mother cell; seen in normal vegetative growth and asexual reproduction.

Mitospore: "Asexual spore" or "conidium"; a spore produced through mitosis.

Muriform: Divided by intersecting crosswalls in more than one plane. See also dictyospore.

Mycelium (pl. mycelia): Network of hyphae making up the non-reproductive part of the body of a fungus.

Mycetoma: Disease caused by fungi involving the invasive infection of tissues under the skin.

Mycosis: Disease caused by fungi.

Mycotoxin: Toxin produced by a fungus.

Myxomycetes: "Slime molds"; not true fungi, organisms within the Kingdom Prototista having a noncellular and creeping vegetative phase and a spore-producing stage.

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Nonsporulating (sterile): Fungi that do not produce structures (asexual or sexual) used in identification.

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Obovate: Oval-shaped like a hen's egg, with the narrower end at the bottom instead of the top.

Olivaceous: Olive green in color.

Onychomycosis: Fungal disease of the nails.

Opportunistic pathogen: A fungus that is normally saprobic, but on occasion is able to cause disease in a host rendered susceptible by predisposing factors.

Ostiole: Opening or pore through which spores are released; see perithecium, pycnidium.

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Parasite: An organism living on or in another living organism, and obtaining nutrients from its host.

Pathogen: An organism capable of causing disease in its host.

Pathogenic: Disease-causing.

"Perfect state": The part of a life cycle of a fungus where sexual reproduction occurs.

Perithecium (pl. perithecia): An enclosed, flask-shaped ascoma with a pore (ostiole) through which ascospores are freed.

Phaeohyphomycosis: A group of fungal infections characterized by the presence of dematiaceous (dark-walled) septate hyphae in tissue.

Phialide: A type of conidiogenous cell (often bottle-shaped) that produces conidia in basipetal succession.

Pycnidium (pl. pycnidia): An asexual, conidial-producing, flask-shaped, fruiting body with a pore (ostiole) through which conidia are freed.

Pyriform: Pear-shaped.

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Q, R

Rhizoid: A slender, branched hypha, similar in appearance to a plant root, whose main function is to attach the fungus to its substrate.

Rusts / Smuts: Two groups of basidiomycetes that have a sexual cycle with two or more types of spores. Both rusts and smuts must colonize living plant host(s) in order to complete their life cycles.

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Saprophyte (syn. saprobe): An organism that uses dead organic matter as food, causing its decay.

Septate: Divided by or having septa.

Septum (pl. septa): A crosswall in a spore or hypha; longitudinal septum: septum that is parallel to the axis of the structure; transverse septum: septum arranged perpendicular to the axis of the structure.

Seta (pl. setae): Stiff hair or bristle.

Soft rot: A type of rot caused typically by ascomycetes (or their anamorphs) that degrades only the cellulose component of the cell wall, leaving the wood soft in texture.

Sporangium: In zygomycetes, the sac-like structure in which asexual spores are produced.

Synnema (pl. synnemata): Erect bundle of conidiophores that bear conidiogenous cells at the tip (and sometimes along the sides).

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Teleomorph: Sexual (perfect) state of a fungus where spores are produced by meiosis.

Toxic mold: A term commonly used in the media to describe Stachybotrys. The term has no scientific meaning. Many molds may produce mycotoxins under appropriate conditions but mold itself is not toxic.

Truncate: Ending abruptly, leaving the end square or broad.

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U, V

Vegetative: Refers to parts of the fungus that are not involved in sexual reproduction.

Verticillate: A type of branching where the branches are arranged around a central axis, like spokes on a wheel.

Vesicle: Swollen and/or bladder-like structure.

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White rot: Fungal decomposition of both cellulose and lignin in wood, giving the wood a pale (yellowish or whitish) color and a moist, fibrous, flexible structure. Mainly caused by basidiomycetes.

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X, Y

Xerophilic: Dry-loving; fungi that prefer dry habitats.

Yeast: Single-celled fungi that reproduce by budding. Yeasts are not a formal taxonomic grouping, but rather a group of unrelated fungi that have similar growth forms. Some fungi grow only as yeasts, while some filamentous fungi may have yeast phases in their life cycles depending on environmental conditions; see dimorphic.

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Zygomycetes: A class of fungi that reproduces asexually by sporangia and sexually by zygosporangia.

Zygomycosis: Fungal disease produced by member of the zygomycetes.

Zygosporangium (pl. zygosporangia): In zygomycetes, the structure that contains the sexually produced spore.

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