Ascospores: Sexual spore borne in an ascus

Ascostroma (pl. ascostromata): A fruiting body containing bitunicate (doublewalled) asci in locules (cavities); usually dark with multiple locules, but sometimes single (see pseudothecium)

Ascus (pl. asci): Sac-like structure containing ascospores (typically eight) and usually borne in a fungal fruiting body

Asexual: Vegetative; without sex organs, gametes, or sexual spores; the imperfect or anamorphic stage of a fungus

Autoecious: In reference to rust fungi, producing all spore forms on one species of host plant (see heteroecious)

Basidium (pl. basidia; adj. basidial):Specialized cell or organ, often club-shaped, in which karyogamy and meiosis occur, followed by production of externally-borne basidiospores that are haploid. There are several types of basidia

Basidiospore: Haploid (1N) sexual spore produced on a basidium

Chlamydospores: Thick-walled or double-walled asexual resting spore formed from hyphal cells (terminal or intercalary) or by transformation of conidial cells that can function as an overwintering stage

Coenocytic: Having multiple nuclei embedded in cytoplasm without cross walls; nonseptate

Conidium (pl. conidia): Asexual, non-motile fungal spore that develops externally or is liberated from the cell that formed it

Dikaryon (adj. dikaryotic): Having two sexually compatible haploid nuclei per cell, that divide simultaneously; this phase is called the dikaryophase

Diploid: Having two complete sets of chromosomes (2N chromosomes) (see haploid, polyploid)

Ergosterol biosynthesis: The chemical reactions and pathways resulting in the formation of ergosterol, a sterol required for fungal cell membrane structure and function

Flagellum (pl. flagella): Appendage of a motile cell, bacterium or zoospore that provides locomotion

Haploid: Having a single complete set of chromosomes (see diploid, polyploid)

Haulm: Stem or stalks collectively

Heteroecious: Pertaining to a rust fungus requiring two unrelated host plants for completion of its life cycle (see autoecious)

Hymenium: Continuous, spore-bearing layer of a fungus fruiting body

Hypha (pl. hyphae; adj. hyphal): Single, tubular filament of a fungal thallus or mycelium; the basic structural unit of a fungus

Karyogamy: The fusion of nuclei

Meiosis: Process of nuclear division in which the number of chromosomes per nucleus is halved, i.e. Converting the diploid state to the haploid state (see mitosis)

Mitosis: Nuclear division in which the chromosome number remains the same (see meiosis)

Motile: Capable of self-propulsion by means of flagella, cilia, or amoeboid movement

Mycelium: Mass of hyphae constituting the body (thallus) of a fungus

Nonseptate: Having no cross walls; lacking septa; coenocytic, aseptate

Oomycetes: Class of fungal-like organisms typically with nonseptate mycelium, asexual sporangia and zoospores, and sexual oospores

Oospore: Thick-walled, sexually-derived resting spore of oomycetes

Perithecium (pl. perithecia): Flask-shaped or sub-globose, thin-walled fungus fruiting body (ascocarp) containing asci and ascospores

Polyploidy: Having three or more complete sets of chromosomes (see haploid, diploid)

Promycelium (pl. promycelia: In rust and smut fungi, a germ tube issuing from the teliospore and bearing the basidiospores

Pseudothecium (pl. pseudothecia): Perithecium-like fruiting body containing asci and ascospores dispersed rather than in an organized hymenium; an ascostroma with a single locule (cavity) and containing bitunicate (double-walled) asci

Pycnidium (pl. pycnidia): Asexual, globose or flask-shaped fruiting body of certain imperfect fungi producing conidia

Saprophyte (adj. saprophytic; syn. saprobe): Organism that obtains nourishment from nonliving organic matter

Sclerotium (pl. sclerotia): A vegetative resting body of a fungus, composed of a compact mass of hyphae with or without host tissue

Sporangiopore: Non-motile, asexual spore that is borne in a sporangium

Sporangium (pl. sporangia): Sac-like fungal structure in which the entire contents are converted into an indefinite number of asexual spores

Teliospore (sometimes called teleutospore): Thick-walled resting or overwintering spore produced by the rust and smut fungi which germinate to form a promycelium (basidium) in which meiosis occurs Tubulin a protein that is the main constituent of the microtubules of living cells

Urediniospore (also urediospore, uredospore): The asexual, dikaryotic, often rusty-coloured spore of a rust fungus, capable of infecting the host plant on which it is produced

Uredinium (also uredium; pl. uredinia): Fruiting body (sorus) of rust fungi that produces urediniospores

Zoospore: Fungal spore with flagella, capable of locomotion in water