Each entry consists of a term (in bold), a definition of the term, and a number in parentheses (0) indicating the source of the definition. Clicking on the speaker icon will give you the pronunciation of the term. (Be sure to close the window for the sound player after each use.) The pencil icon will give you a drawing, and the camera icon will give you a photograph.

facultative anaerobe. Refers to an organism that normally grows aerobically but can grow anaerobically. (16)

facultative parasite. An organism that normally lives as a saprophyte but under certain conditions can live as a parasite. (15)

facultative saprophyte. A mainly parasitic organism with the ability to survive for a part of its life cycle as a saprophyte and be cultured on artificial media. (11)

falcate. (Of spores) sickle-shaped. (17)

fallow. Previously cultivated land kept free from crops or weeds during at least one growing season. (6)

fasciation. Hyperplastic symptoms characterized by a fusing (and flattening) of such plant organs as stems. (20)

fasciculation. Hyperplastic symptom characterized by a clustering of such plant organs as shoots into such structures as witches' brooms. (20)

fenestra. In nematodes: A window or transparent spot; in some Heteroderidae, a thin-walled region of the vulval cone. (Pl. fenestrae.) (14)

fenestrate. Having a fenestra. (14)

fenestration. The area in which the fenestra occurs. (14)

fermentation. Oxidation of certain organic substances in the absence of molecular oxygen. (2)

filiform. Thread-shaped. (14)

fission. Cell division by cleavage (splitting) of the cell into two parts. (15)

fitness. The ability of an organism to survive and reproduce; the ability of an organism to pass its genes to the next generation. (8)

flagellate. Having one or more flagella. (20)

flagellum. A whip-like appendage responsible for motility in the majority of motile bacteria and other protists, fungi, algae, etc. (Pl. flagella.) (16)

flexure. A turn or fold. (14)

form genus. A non-phylogenetic category, equivalent to genus, distinguished on the basis of one or more morphological features. In the Deuteromycotina, form genera are used to classify anamorphs; such form genera are based primarily on the characteristics (including mode of development) of the conidia, conidiophores, and conidiomata. (16)

form species. A non-phylogenetic category, equivalent to species, distinguished on the basis of one or more morphological features of an anamorph, treated as if it were an independent entity, especially for indexing or identification purposes; of importance chiefly in the Ascomycetes and Uredinales. (17)

forma_specialis. Literally "special form". An infraspecific taxonomic rank in which the taxa are distinguished on a physiological basis, particularly on the basis of adaptation to (or pathogenicity for) one or more specific hosts. In mycology, forma specialis is a taxonomic rank lower than form, subvariety, variety and subspecies, and higher than physiological race. Abbreviated f. sp. (pl. f. spp.) (Pl. formae speciales.) (16)

freeze-drying. See lyophilization.

fructification. 1. Synonymous with fruiting body. 2. The formation or development of a fruiting body. (16)

fruit body. See fruiting body.

fruiting body. Any multi-hyphal structure that bears or contains spores. (16)

fumigant. A gas or volatile substance that is used to disinfest certain areas of various pests. (2)

fungicidal. Kills fungi.

fungi imperfecti. See Deuteromycotina. (17)

fungicide. A chemical or physical agent that kills or inhibits the growth of fungi. (Note some substances termed "fungicides" are fungistatic in their action. (15)

fungistasis. Inhibition of fungal growth or reproduction that is not lethal. (15)

fungistat. A substance that prevents fungal growth without killing the fungus. (8)

fungistatic. Able to inhibit the growth and/or reproduction of at least some types of fungi. (16)

fungus. A eukaryotic, heterotrophic organism whose usually walled, threadlike cells absorb nutrients. (Pl. fungi.) (15)

furcate. Forked. (14)

fusiform. Spindle-shaped; tapering at each end. (14)