Glossary of Mycological Terms

Additional Reference: Hawksworth DL, PM Kirk, BC Sutton, DN Pegler. 1995. Ainsworth & Bisby's Dictionary of the fungi. International Mycologyical Institute.

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 |

A

Acrogenous: Conidia born at the tip of the conidiophore.

Acropetal: A chain of conidia in which the youngest conidium is at the tip and the oldest is at the base.

Acropleurogenous: Conidia developing at the tip and along the sides of the conidiophore.

Adiaconidia: A large, globose, thick-walled conidium, usually produced by Emmonsia (Chrysosporium) parvum, in the lungs of humans and animals.

Aerial mycelium: Hyphal elements growing above the agar surface.

Aleurioconidium (pl. aleurioconidia): A thallic conidium released by lysis or fracture of the supporting cell.

Ameroconidium (pl. ameroconidium): A one-celled conidium.

Anamorph: An asexual state of a fungus.

Annellide: A specialized conidiogenous cell producing conidia in basipetal succession by a series of short percurrent proliferations (annellations). The tip of an annellide increases in length and becomes narrower as each subsequent conidium is formed.

Annelloconidium (pl. annelloconidia): A conidium produced by an annellide.

Apophysis: A swelling. The term is primarily applied to the funnel-shaped swelling of a sporangiophore, immediately below the columella, seen in some zygomycetes.

Arthric: A type of conidial ontogeny involving the conversion and subsequent disarticulation of a determinant conidiogenous hypha.

Arthroconidium (pl. arthroconidia): A thallic conidium released by either the splitting of a double septum or by the fragmentation or lysis of a disjunctor cell.

Ascocarp: A fruiting body containing asci and ascospores.

Ascomycetes: A group of fungi that reproduce sexually by the endogenous formation of ascospores in an ascus.

Ascomycetous: Referring to the Ascomycetes.

Ascospore: A haploid spore produced within an ascus following karyogamy and meiosis.

Ascus (pl. asci): A sac-like cell containing ascospores. Asci are characteristic of the Ascomycetes.

Aseptate: Lacking septa, often pertaining to the hyphae seen in zygomycetes (also see coenocytic).

B

Ballistoconidium (pl. ballistoconidia): A conidium that is forcible discharged.

Basidiomycetes: A group of fungi that reproduce sexually by the exogenous formation of basidiospores from a basidium.

Basidiospore: A haploid spore produced on a basidium following karyogamy and meiosis.

Basidium (pl. basidia): A cell that gives rise to a basidiospore. Basidia are characteristic of the Basidiomycetes.

Basipetal: A chain of conidia, the oldest conidium is at the apex and the youngest is at the base.

Basocatenulate: A chain of conidia having the youngest cell at the base.

Bipolar budding: Blastoconidia developing at the opposite poles of a parent cell.

Biseriate: Phialides arising from metulae as in the genus Aspergillus.

Biverticillate: Two or rarely three levels of branching directly below the phialides as in the genus Penicillium.

Blastic: A form of conidial development where there is a recognizable enlargement or "blowing out" of a conidial initial before being delimited by a septum.

Blastocatenate: A chain of conidia having the youngest cell at the tip.

Blastoconidium (pl. blastoconidia): An asexual conidium that forms by a blowing out or budding process.

Bud: A young conidium. Usually used to denote the young blastoconidia of yeasts.

Budding: Asexual multiplication by the production of a small outgrowth or bud from a parent cell.

C

Capsule: A hyaline mucopolysaccharide sheath around the cell wall of certain yeasts e.g. Cryptococcus and Rhodotorula.

Catenulate: Conidia arranged in chains.

Chlamydoconidium (pl. Chlamydoconidia): A thick-walled, thallic conidium formed within the vegetative hyphae. Chlamydoconidia function as organs of perennation rather than dissemination.

Clamp connection: A specialized hyphal bridge over a septum in the Basidiomycetes.

Clavate: Club-shaped.

Cleistothecium (pl. cleistothecia): An enclosed ascocarp containing randomly dispersed asci.

Coenocytic: Infrequently septate, multi-nucleate hyphae as in the Zygomycetes.

Collarette: A small collar. Usually, a remnant of a cell wall present at the tip of a phialide, or around a sporangiophore.

Columella (pl. columellae): A sterile dome-like structure at the tip of a sporangiophore or within a sporangium.

Columnar: Forming a column.

Conidiogenous cell: A cell that forms conidia.

Conidiophore: A specialized hypha upon which conidia develop.

Conidium (pl. conidia): An asexual reproductive propagule formed in any manner that does not involve cytoplasmic cleavage. Conidia function as organs of dissemination.

Cottony: Having a loose and coarse texture.

Cylindrical: Cylindric, having parallel walls and circular cross-section.

D

Dematiaceous: A dark brown, greenish gray or black colour.

Dermatophyte: A fungus belonging to the genera Epidermophyton, Microsporum, or Trichophyton with the ability to utilize keratin to infect hair, nail and skin.

Denticle: A small projection or peg on which conidia are produced.

Determinate conidiophore: The conidiophore does not alter in length after the formation of conidia.

Deuteromycetes: An artificial subdivision to accommodate those fungi where only the asexual state is known.

Dichotomous: A type of hyphal branching into two equal forks.

Dictyoconidium (pl. dictyoconidia): A conidium with both longitudinal and transverse septa; a muriform conidium.

Didmoconidium (pl. didymoconidia): A two celled conidium.

Dimorphic: Having two different morphological forms.

Disjunctor cell: An empty cell that fragments and/or undergoes lysis to release a conidium.

Dolipore septum: A characteristic septum found in the Basidiomycetes that flares out near the pore to form an elongate channel.

Double septum: A two layered septum that may undergo centripetal separation (schizolysis) to release a conidium.

Downy: Having a short and dense mycelial texture.

Dysgonic: A slow growing variant.

E

Echinulate: Covered with delicate spines.

Ectothrix: Natural hair invasion by a dermatophyte characterized by arthroconidia on the outside of the hair shaft.

Effuse: Spread out, radiate.

Elliptical: Oval, with a symmetric curve.

Elongate: Lengthened.

Endospore: A spore produced within a spherule.

Endothrix: Natural hair invasion by a dermatophyte characterized by the development of arthroconidia within the hair shaft only.

Erect: Upright.

Evanescent: Disappearing.

Exudate: Droplets of fluid formed on the surface of a colony.

F

Falcate: Curved like a sickle.

Flexuous: Wavy.

Floccose: Fluffy or cottony.

Foot cell: A basal cell of a conidiophore as seen in Aspergillus and Fusarium.

Fusiform: Spindle-shaped, tapering toward the end.

G

Geniculate: Bent like a knee.

Germ tube: The initial hypha that develops from a conidium or spore.

Glabrous: Smooth.

Gloiospora: Conidia aggregated in slimy heads at the tip of an annellide or phialide.

Guttulate: Containing one or more oil droplets.

Gymnothecium (pl. gymnothecia): A non-ostiolate ascocarp composed of loosely interwoven hyphae and containing randomly dispersed asci.

H

Heterothallic: A fungus that requires mating between two compatible strains for sexual reproduction to occur.

Hilum: A scar at the base of a conidium.

Holoblastic: A mode of blastic conidium ontogeny in which all the cell wall layers of the conidiogenous cell are involved in conidium development.

Holothallic: A mode of thallic conidium ontogeny in which all the cell wall layers of the conidiogenous cell are involved in conidium development.

Homothallic: A fungus capable of sexual reproduction on a single thallus.

Hulle cells: Thick-walled cells with characteristic thin-walled pores, usually associated with cleistothecia of Aspergillus.

Hyaline: Colourless.

Hyalo-: A prefix meaning hyaline to lightly coloured.

Hypha (pl. hyphae): A single filament of a fungus.

Hyphomycetes: A class of mycelial moulds which reproduce asexually by conidia on hyphae or aggregations of hyphae.

I

Intercalary: Within a hyphal element.

J

K

L

Lageniform: Flask-shaped.

Lanceolate: Lance-shaped.

Lanose: Woolly.

Lateral: On the side.

Lenticular: Shaped like a double convex lens.

M

Macroconidium (pl. macroconidia): The larger of two different types of conidia produced by a fungus in the same manner.

Macronematous: Having a conidiophore that is morphologically different from the vegetative hyphae.

Merosporangium (pl. merosporangia): A small cylindrical sporangium with the sporangiospores aligned in a row.

Metula (pl. Metulae): A sterile cell below the phialides of some Aspergillus and Penicillium species.

Microconidium (pl. microconidia): The smaller of two different types of conidia produced by a fungus in the same manner.

Micronematous: Having a conidiophore that is not morphologically different from the vegetative hyphae.

Mucoid: Sticky or slimy

Multiseptate: Having several septa.

Multipolar budding: Blastoconidia developing at different sites on the surface of a parent cell.

Muriform: A conidium with both longitudinal and transverse septa.

Mycelium (pl. mycelia): The mass of hyphae making up the thallus of a fungus.

N

Niger: Black.

Nonseptate: Without septa.

O

Obclavate: Club-shaped in reverse; the distal region is smaller.

Obpyriform: Pear-shaped in reverse; the distal region is larger.

Olivaceous: Olive-grey colour.

Ostiole: An opening or pore in an ascocarp or a pycnidium.

Ovoid: Egg-shaped.

P

Pectinate: Like the teeth of a comb.

Pedicel: A slender stalk.

Pellicle: A film-like or skin-like surface growth.

Penicillus (pl. penicilli): The brush-like conidiophore of Penicillium.

Percurrent: Conidiogenous cell growth where a new axis grows through the previous apex.

Peridium: The outer wall of an ascocarp.

Perithecium (pl. perithecia): An enclosed ascocarp characterized an apical ostiole and by asci arranged in a basal tuft or hymenium layer.

Phaeo-: A prefix meaning darkly pigmented.

Phialide: A specialized conidiogenous cell that produces conidia in basipetal succession without increasing in length.

Phialoconidium (pl. phialoconidia): A conidium produced from a phialide.

Phragmoconidium (pl. phragmoconidia): A conidium having two or more transverse septa.

Pleomorphic: Having more than one form.

Pleurogenous: Born on the sides of a conidiophore or hyphae.

Poroconidium (pl. poroconidia): A conidium produced through a small pore in a conidiogenous cell.

Pseudohyphae: A string of elongated blastoconidia formed in some yeasts that resemble a hypha-like filament.

Pycnidium (pl. pycnidia): An asexual fruiting body containing conidia.

Pyriform: Pear-shaped.

Q

R

Rachis: An extension of a sympodial proliferating conidiogenous cell bearing conidia.

Racquet hyphae: A hypha composed of a number of cells swollen at one end resembling a tennis racquet.

Retrogressive conidial development: The conidiogenesis cell becomes shorter during the successive development of conidia.

Rhizoids: A short branching root-like hyphae seen in some Zygomycetes.

S

Sclerotium (sclerotia): A mass of thick-walled cells formed by the vegetative hyphae that function as an organ of perennation.

Semimacronematous: Having a conidiophore that is only slightly morphologically different from the vegetative hyphae.

Septum (pl. septa): A cross wall in a hypha.

Spinulose: Covered in small spines.

Solitary: Alone.

Sporangiolum (pl. ): A small sporangium producing a small number of sporangiospores.

Sporangiophore: A specialized hypha that bears a sporangium.

Sporangiospore: An asexual spore produced within a sporangium.

Sporangium (pl. sporangia): A sac-like structure producing asexual spores endogenously by cytoplasmic cleavage.

Spore: a reproductive propagule formed by either meiosis or mitosis. However, if by asexual means, cleavage of cytoplasm is usually involved.

Sporodochium (pl. sporodochia): A cushion-shaped mass of hyphae bearing conidiophores.

Stellate: Star-shaped

Sterigma (pl. sterigmata): A small pointed structure upon which a basidiospore forms.

Stolon: A running hypha from which rhizoids and sporangiospores arise.

Striate: Having lines or minute furrows.

Subglobose: Not quite round or spherical.

Sympodial: A mode of conidiogenous cell growth which results in the development of conidia on a geniculate or zig-zag rachis.

Synnema (pl. synnemata): A group of erect conidiophores that are cemented together producing conidia at the apex and/or along the sides.

T

Teleomorph: The sexual state of a fungus.

Thallic: A mode of conidial ontogeny where a conidium is formed from a pre-existing hyphal segment or cell.

Toruloid: Having swellings at intervals.

Truncate: Cut off sharply.

Tuberculate: Having small wart-like structures.

U

Uniserate: Phialides arising directly from a vesicle as in Aspergillus.

V

Verrucose: Having many warts.

Verticillate: Having branches arranged in verticils or whorls.

Vesicle: A swollen cell.

W

X

Y

Z

Zygospores: A thick-walled sexual spore formed by the fusion of two similar gametangia; characteristic of the Zygomycetes.