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Glossary / Glossaire

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.