Warning This Web page has been archived on the Web.

Archived Content

Information identified as archived on the Web is for reference, research or recordkeeping purposes. It has not been altered or updated after the date of archiving. Web pages that are archived on the Web are not subject to the Government of Canada Web Standards. As per the Communications Policy of the Government of Canada, you can request alternate formats on the Contact Us page.

Glossary


Skip to letter
| 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 (top)

abaxial: the upper surface of a leaf or needle.

acute: pointed, sharp-edged, less than a right angle.

acyanophilous (cf. cyanophilous): not readily absorbing a blue stain such as cotton blue or gentian violet.

advanced decay: advanced destruction of plant or animal matter by fungi or other micro-organisms. Wood tissue is generally soft.

aeciospore: binucleate asexual spores of rust fungi formed as a result of the sexual fusion of cells but not of the nuclei.

aecium (pl. -ia): site of production of aeciospores in the rust fungi.

alternate host: one or the other of the two unlike hosts of a heteroecious rust fungus.

amphigenous: growing all around or on both sides of a leaf or needle.

ampulliform: flask-shaped.

amyloid: spores and hyphae are designated as amyloid if they turn grey or blue-black upon treatment with Melzer's Iodine reagent (see dextrinoid, IKI-).

annual: a plant that completes its life cycle within 1 year and then dies.

annulus: the ring of tissue left on the stalk (stipe) of a mushroom when the partial veil (pileus) breaks.

apiculus: a short projection at one end of a spore.

apothecium (pl. -ca): the cup or saucer-shaped fruiting body of the Ascomycotina.

arthroconidium (pl. -ia): an asexual spore produced from the division a hypha into separate cells.

aseptate: without crosswalls, generally referring to fungal hyphae.

ascus (pl. -ci): a sac-like cell of an Ascomycete within which two haploid nuclei fuse, after which three divisions occur, two of them meiotic, resulting in eight ascospores.

ascospore: a sexually generated propagative unit of the Ascomycotina, a spore produced within an ascus.

ascostroma (pl. -mata): a stroma containing asci.

asexual stage (cf. sexual stage): that part of a life cycle where reproduction does not involve the fusion of gametes and meiosis.


B (top)

bacillar: rod-like in form.

basidiospore: a propagative cell of the Basidiomycotina containing one or two haploid nuclei produced, after meiosis, on a basidium.

bilabiate: from the Latin two-lipped, describing a dehiscence mechanism in bitunicate asci where the tip of the ascus splits to form two lips

biseriate: arranged in or having two series or rows.

bitunicate: having two walls, as in the asci of Loculoascomycetes.


C (top)

callus: wound tissue, composed of soft parenchymatous tissue formed on or about injured surfaces of stems and roots.

cambium: a persistent layer of generative, meristematic cells that gives rise to secondary wood (xylem) and secondary inner bark (phloem).

canker: a disease of woody plants characterized by sharply delimited necrosis of the cortical tissues and malformation of the bark caused by recurring localized killing of the cambium layer.

caulicolous: living on herbaceous stems.

chlamydospore: an asexual spore (primarily for survival, not dissemination) formed by modification of a hyphal segment.

chlorosis (adj. chlorotic): an unseasonable yellowing of the foliage, symptomatic of a chlorophyll deficiency in the leaf tissues.

circumscissile: opening or cracking along a circle.

clamp connection (also clamp): a bridge-like hyphal connection characteristic of the secondary mycelium of many Basidiomycetes.

clavate: club-like, narrowed at the base.

clypeus: a shield-like growth over a perithecium.

concolorous: of one colour

conidium (pl. -ia): an asexual fungal spore.

conidiophores: a specialized hypha from which conidia are produced.

conk: a fruiting body of a wood-destroying fungus.

context: the inner or body tissue of a fruiting body that supports the fruiting surface.

cyanophilous (cf. acyanophilous): readily absorbing a blue stain such as cotton blue or gentian violet.

cystidium (pl. -ia): a sterile structure, frequently of distinctive shape, generally occurring on the hymenial surface of a basidiomycete fruiting body.


D (top)

daedaloid: pores that are irregularly lobed and sinuous in outline, labyrinthiform.

dextrinoid: spores and hyphae are designated as dextrinoid if they turn reddish-brown upon treatment with Melzer's Iodine reagent (see amyloid, IKI-).

dieback: the progressive dying, from the tip downward, of twigs, branches, tops, or roots of plants.


E (top)

echinulate: covered with slender sharp spines, here referring to spore surface characteristics.

effused-reflexed: spread out over the substratum and turned back at the margin; refers to the growth form of polypore fruiting bodies.

epidemic: a widespread high level of disease incidence beyond normal proportions.

epidermis: a superficial layer of cells occurring on all parts of the primary plant body; stems, leaves, roots, flowers, and seeds.

epiphyllous: growing on the upper, adaxial surface of a leaf or needle.

episporium (also epispore): the thick fundamental layer that determines the shape of the spore.

erumpent: bursting through the bark.

excipulum: tissues of the apothecium; ectal-, forms outermost layers, including the margin, and medullary-, the zone enclosed by the ectal excipulum and the hypothecium.


F (top)

filiform: thread-like.

flag (also flagging): a dying, or recently dead, twig or branch, the foliage of which contrasts in colour with the normal green foliage of living trees.

fruiting body (also sporophore, conk): a structure that bears the spore-producing structures and spores in fleshy and woody higher fungi.

fungus (pl. -gi): one group of the lower plants that lack chlorophyll, thus requiring a host from which to obtain food.

fusoid: almost fusiform.

fusiform: spindle shaped, tapering at both ends.


G (top)

generative hyphae: the hyphal type present in all basidiocarps, typically thin-walled, with clamps or simple-septate; from them develop the hymenial elements, and in some species, the skeletal and binding hyphae.

geniculate: bent like a knee.

germ pore: a thin circular area in the spore wall through which the germ tube develops.

guttulate: having one or more oil drops inside.


H (top)

heartwood: the central part of a tree that is no longer active in the transport or storage of water or nutrients.

host: a plant or other organism that furnishes subsistence to, or harbours, a parasite.

hypha (pl. -ae): a fungal thread or filament.

hyaline: transparent, colourless.

hymenium: the spore bearing layer of a fungal fruiting structure.

hyperparasite (adj. -itic): a parasite that is parasitic on another parasite.

hypertrophy: the state of having growth greater than normal.

hypophyllous: growing on the lower, abaxial surface of a leaf or needle.

hypothecium: the hyphal layer under the hymenium of an apothecium.

hysterothecium (pl. -cia): an elongated ascocarp with an longitudinal slit; characteristic of some needle-cast fungi.


I (top)

IKI-: no colour response when treated with Melzer's Iodine reagent; sometimes referred to as inamyloid (see amyloid, dextrinoid).

incipient decay: an early stage in decay in which the wood may show discoloration but is not otherwise visibly altered. The wood is generally firm and sound.

indeterminate: having the edge not well defined, especially of fruit-bodies and leaf-spots; continuing growth indefinitely.

infection court: the site of invasion of a host by a pathogen.

inoculum: spores or tissue of a pathogen that serve to initiate disease in a plant.

intercalary: between apex and base.


J (top)

J-: does not stain in iodine; common usage in Ascomycete identification.


K (top)


L (top)

laccate: polished, varnished, shining.

laminate: separated into sheets or layers (lamellae).

lenticular: like a double convex lens in form.

lesion: a definite, localized area of dead tissue, a circumscribed diseased area.

locule: a cavity in a stroma.


M (top)

Melzer's reagent: a solution consisting of 2.5 g iodine, 7.5 g potassium iodide, and 100 g chloral hydrate per 100 mL of water used to detect amyloid and dextrinoid reactions.

monostichous: forming in a line; refers here to the alignment of ascospores in as ascus.

mycelial fan: a fan-shaped mycelial mat forming under the bark of roots and lower stems of trees; often associated with Armillaria root rot.

mycelium: collective term for hyphae or fungus Filaments.


N (top)

necrosis: death of the affected tissues.


O (top)

obligate parasite: a parasite that is incapable of existing independently of living tissues.

ostiole: a pore through which spores are freed from a perithecium or pycnidium.


P (top)

papillate: small, rounded.

paraphyses: sterile structures in a hymenium.

parasite: an organism that draws a part or the whole of its nourishment from another living organism.

parenchyma: tissue composed of more or less isodiametric cells, usually thin-walled with intercellular spaces (cf. pseudoparenchyma).

pathogen: an organism capable of causing disease.

pathogenic: disease-causing or able to be so.

penicillate: like a little brush.

perennial: an organism that lives from year-to-year.

Peridium (pl. -ia): the wall or limiting membrane of a sporangium or other fungal fruiting structure

periderm: the outermost, corky layer of bark of a tree.

peridermioid: more or less like the peridermium.

peridermium (pl. -ia): an aecium with a blister-like, tongue-shaped, or cylindrical peridium.

perithecium: the sub-globose or flask-shaped ascocarp of an Ascomycete fungus.

phloem: food-conducting tissue, consisting of sieve tubes, companion cells, phloem parenchyma, and fibers.

phialide (adj. phialidic): a type of conidiogenous cell that produces conidia through a special opening where neither wall contributes toward formation of the conidium; conidia are produced basipetally with no detectable increase in length.

plectenchyma: fungaL tissue formed by hyphae becoming twisted and fixed together.

pore: an opening on the fertile surface of bolete and polypore fungi, through which basidiospores are disseminated.

pore surface: the surface of polypore or bolete fruiting body bearing pores through with basidiospores are disseminated.

poroid: with pores.

pseudooperculum: characteristic of one of nine structural types of ascus (pseudooperculate).

pseudoparaphyses: sterile hyphal structures connected to both the upper and lower surface of and ascocarp.

pseudoparenchyma: plant tissue composed of more or less isodiametric cells.

punk knot: decayed branch stubs that often indicate the presence of decay in a tree.

pustule: a blister-like, frequently erumpent, spot or spore-mass.

pycnidium: a flask-shaped, asexual fruiting body lined with conidiophores.

pyriform: pear-shaped.


Q (top)


R (top)

resinosis: an abnormal exudation of resin or pitch from conifers.

resupinate: a fruiting body reclined or flat on the substratum.

reverse: refers to the colour of the bottom of a petri plate on which a fungal culture is growing.

rhizomorph: a strand or cord of compact mycelium, often dark coloured; characteristic of Armillaria spp.

rugulose: delicately wrinkled.


S (top)

semipileate: with a cap that is partially appressed to the substrate.

saprophyte: an organism using dead organic material as food.

septate: possessing a cross-wall forming a division in a spore or hypha.

seta: a stiff hair or bristle.

sexual stage (cf. asexual stage): that part of a life cycle where reproduction involves the fusion of gametes and meiosis.

sign: visible evidence of a disease organism, (e.g., mycelium, fruiting bodies).

skeletal hyphae: thick-walled hyphae, branched or unbranched, aseptate, straight or slightly flexuous with thin-walled apices.

spermatium (pl. -ia): non-motile, uninucleate, spore-like male structure serving as a gamete in sexual reproduction.

spermagonium (pl. -ia): a fruiting structure in which spermatia are produced, sometimes referred to as a pycnium in some rust fungus literature.

spore: the reproductive structure of fungi and other cryptograms, corresponding to a seed in flowering plants.

sporodochium (a): a cushion-shaped conidial fruiting structure in which the spore mass is supported by a stroma covered by short conidiophores.

sporophore: see fruiting body.

sterigma (pl. -ata): a tapering projection on a basidium on which basidiospores develop.

sterile conk: a conk not producing spores or a sporocarp.

stipe: a stalk-like or stem-like structure that supports the pileus of a basidiomycete fruiting body.

stipitate: possessing a stipe.

stroma (pl. -ata): a mass or matrix of vegetative hyphae, with or without tissue of the host or substrate, sometimes sclerotium-like in form, in or on which spores are produced.

subcuticular: underlying the cuticle.

subhypodermal: underlying the hypodermis.

subiculum: a net-like, or crust-like growth of mycelium from which fruiting bodies are formed.

subulate: tapering to a point; awl-shaped.

symptom: the noticeable evidence of change in the physiology or morphology of a host as a result of disease.

systemic: a parasite which spreads throughout the host; a fungicide that is absorbed by the roots and is translocated to other parts of the plant.


T (top)

telium (pl. -ia): a sorus producing teliospores; refers to rust fungi.

teliospore: a spore (commonly a winter or resting spore) of the rust fungi from which the basidium is produced.

terminal vesicle: the swollen apex of the conidiophore or hypha.

tramal hyphae: the layer of hyphae in the central part of a lamella of an agaric, a spine of Hydnaceae, or the partition between pores in a polyphore.

tuberculate: having tubercles, having small wart-like processes.

tubes: spore-bearing structures in polypores and boletes, aligned vertically and terminating in openings on the pore surface.


U (top)

uniseriate: arranged in or having one series or row.

urediniospore: a binucleate spore borne in a uredinium and capable of infecting the same host on which it originated, usually echinulate.

uredinium (pl. -ia): a sorus that produces urediniospores, produced after the aecium and after the telium in the life cycle of rust fungi.


V (top)

verruculose: possessing delicate, small rounded processes or warts.

verticillate: having parts in rings (verticils), whorled.

virulence: degree of pathogenicity of a pathogen, the relative capacity of a pathogen to cause disease.


W (top)


X (top)

xylem: a plant tissue consisting of tracheids, vessels, parenchyma cells and fibers; wood.


Y (top)


Z (top)

zone lines: narrow, dark-brown or black lines in decayed wood, generally resulting from the interaction of different strains or species of fungi.