Glossary
GLOSSARY
acicular: needle-shaped.
acute: sharply pointed.
adnate: closely attached, appressed - used of the attachment of fruit to thallus, or of thallus to substrate.
aeruginose: blue-green.
aggregate: clustered (also used for groups of closely-related species).
alate: winged.
amyloid: staining blue-purple in iodine.
anamorph: conidial state of lichenised fungi.
anastomosing: joining up, running into each other - used of branched paraphyses which form a network.
angiocarpic: closed (of a sporocarp) at least until spores are mature.
angustate: narrowed.
anisotomic: unequal branching, with a distinct main axis and smaller lateral side branches.
annular: ringed.
annulation: ring-like, often pigmented cortical zone, especially of branches of Neuropogon.
anticlinal: perpendicular to the surface.
apical: situated at tip.
apiculate: ending in a short, slender, ± flexible projection.
apothecium: a ± flat, disc-like fruit, either round (cf. Lecanora) or elongate (cf. Opegrapha) - see also discocarp; pl. apothecia.
appressed: closely and flatly pressed against a surface.
arachnoid: cobwebby.
arcuate: bent, curved or arched.
areola: small area, rounded, ± polygonal or angular, delimited by cracks or chinks on thallus surface.
areolate: island-like, sharply divided into areolae by separating cracks.
articulate: jointed.
ascending: directed upwards at a rather narrow angle, curving upwards.
ascocarp: ascus-bearing organ of ascomycete.
ascogenous: ascus-producing or -supporting.
ascogones (ascogonium): cell or group of cells in Ascomycotina fertilised by a sexual process.
ascohymenial: Ascomycotina having asci and paraphyses arranged as a hymenium, as in pyrenomycetes and discomycetes.
ascolocular: Ascomycotina having asci in cavities, as in loculoascomycetes.
ascoma: a sporocarp having asci, pl. ascomata.
Ascomycotina (Ascomycetes): class of fungi in which spores are developed in asci.
ascospore: a spore produced in an ascus by "free cell formation".
ascus: sac-like cell of the perfect state of an ascomycete, in which ascospores (usually 8) are produced; pl. asci.
ascyphous: without a cup.
aspicilioid: (of lecanorine apothecia) ± immersed in thallus, at least when young.
attenuate: gradually tapering.
autonomous: independent, separate.
axis: main stem, or central longitudinal support.
bacill -ar, -iform: rod-like in form.
basidiocarp: basidium-bearing organ of Basidiomycotina.
Basidiomycotina (Basidiomycetes): class of fungi in which spores develop on basidia.
basidiospore: spores from a basidium.
basidium: organ in Basidiomycotina which, after karyogamy and meiosis, bears the basidiospores; pl. basidia.
biatorine: (of lichen apothecia) of lecideine type, pale or ± coloured, soft in consistency.
biguttulate: having two oil droplets.
bilocular: two-celled (of a spore).
bipolar: occurring in both Arctic and Antarctic regions, but disjunct to varying degrees between the polar regions.
blastidia: small subsidiary locules in a thick-walled spore.
boreal: pertaining to the circumpolar bioclimatic zone, also called the northern coniferous zone or taiga.
bullate: with surface blistered or puckered.
byssoid: cottony, composed of delicate threads, floccose.
caespitose: growing in dense low tufts or cushions.
canaliculate: longitudinally channeled or grooved.
capillary: hair-like.
capitate: having a well-formed head, swollen at apex.
capitulum: globose apical apothecium of Caliciales, cf. mazaedium.
carbonaceous: black, opaque.
cartilaginous: firm and tough but readily bent, gristly.
catenulate: linked together.
cephalodium: a delimited region within, or a warty, squamulose or fruticose structure on the surface of, a lichen thallus containing a photobiont different to that characteristic of the rest of the thallus. Generally cephalodia contain blue-green photobionts (e.g., Nostoc) while the rest of the thallus has a green photobiont (e.g., Trebouxia). Nostoc in cephalodia fix atmospheric nitrogen. Genera containing cephalodia include: Argopsis, Coccotrema, Lobaria, Placopsis, Psoroma, Psoromidium, Pseudocyphellaria, Solorina, Stereocaulon, Sticta and Thysanophoron.
cerebriform: brain-like, convoluted.
chemodeme: group of chemically differentiated individuals of a species, of unknown or of no taxonomic significance.
chondroid: tough, cartilaginous.
cilium: a short, eyelash-like hair, usually marginal on fruits or thallus; pl. cilia.
circumpolar: used of a species occurring in a broad latitudinal zone in Arctic and Subarctic, or Antarctic and Subantarctic regions.
citrine: lemon-yellow.
clathrate: like a network, latticed.
clavarioid: having the appearance of Clavaria.
clavate: club-shaped.
clypeate: having a shield-like stromatic growth around the ostiole of an ascocarp.
cochleate: shell-like.
complicate: folded, bent upon itself.
concave: hollowed out, basin-like.
concentric: arranged around a common centre.
concolorous: of one or the same colour.
confluent: blending or running together.
congested: crowded.
conglomerate: clustered.
conglutinate: glued or stuck together.
conidium: spore type produced in a pycnidium; pl. conidia.
contextual: of the tissue lying between the hymenial layer and the upper surface in a basidiocarp.
contiguous: touching but not fused.
continuous: without breaks, uninterrupted.
contorted: twisted.
convex: equally rounded, broadly obtuse.
coralloid: coral-like often brittle (usually of isidia).
coriaceous: leathery.
coronate: crowned (used especially of fruits that are surrounded by lobes of thallus).
corrugate: wrinkled.
cortex: the outermost layer of the thallus which, if present, consists of compacted hyphae which may appear either fibrous or cellular.
corticate: having a cortex.
corticolous: growing on bark.
corymbose: arranged in clusters.
costate: veined or ribbed.
crenate: scalloped with small, rounded notches or teeth, the sinus acute.
crenulate: delicately crenate.
crisped: of a margin crumpled or thrown into waves.
crustose: crust-like, used for lichens having a thallus stretching over and firmly fixed to the substratum by the whole of their lower surface, such thalli generally lack rhizines and a lower cortex.
cryptolecanorine: with a reduced or inapparent thalline margin (of an ascocarp).
cuneate: thinner at one end than the other, wedge-shaped.
cyphella: a break in the lower cortex of a lichen thallus which is rounded or ovate or effigurate and in section appears as a cup-like structure lined with a layer of loosely-connected, frequently globular cells formed from the medulla, characteristic of the genus Sticta; pl. cyphellae.
decorticate: without a cortex.
decumbent: resting on substratum, with ends turned up.
decurrent: descending the stem.
deflexed: bent sharply downward.
delimited: having a distinct restricting edge or margin.
dendroid: irregularly branched, tree-like.
dense: closely interwoven.
dentate: toothed.
denticulate: delicately toothed.
determinate: having a distinct, defined form.
diaspore: any propagule, sexual or asexual.
dichotomous: branching, often successively, into two ± equal arms.
diffract: cracked into small areas, areolate.
diffuse: widely or loosely spreading, with no distinct margin.
dimidiate: appearing to lack one half or having one half very much smaller than the other (of a compound ascocarp).
dimorphic: having two forms.
disc: round, plate-like or curved spore-producing part of fruit body, upper surface of discocarp.
discocarp: ascocarp in which hymenium is uncovered when asci and ascospores are mature, an apothecium.
discoid: flat and circular, disc-like.
dorsal: back or upper surface, surface facing away from the axis.
dorsiventral: with distinct upper and lower surfaces.
disjunct: of a population, of a species widely separated geographically or otherwise from other populations of the same species.
divergent: spreading away from one another, usually at a rather wide angle.
ecorticate: without a cortex.
effigurate: having a definite form or figure.
effuse: stretched out flat especially as a film-like growth.
ellipsoid: elliptical in optical section (of spores).
elliptical: oval or oblong narrowed at each end.
endemic: occurring only in a single, usually small, geographic area.
endolithic: immersed in stone.
endophloeodal: immersed in bark.
endosubstratic: growing within the substrate.
entire: with a continuous margin.
epihymenium: uppermost (often pigmented) layer of hymenium, above asci.
epilithic: growing on surface of rocks or stones.
epiphloeodal: growing on bark.
epiphyllous: growing on the surface (usually upper) of leaves, the mycobiont not penetrating the leaf surface.
epiphyte: a plant growing on another but not organically connected with it.
epipsamma: granular zone (usually pigmented) permeating upper parts of hymenium but ± distinct from epithecium, especially in Rhizocarpon.
epispore: thin outer covering of a spore.
episubstratic: growing upon substrate.
epithecium: upper part (3-15 µm) of hymenium where this differs in appearance from lower part - layer of uppermost parts of paraphyses overtopping asci, often pigmented.
epruinose: without pruina.
erumpent: bursting through surface.
esorediate: without soredia.
eutrophicated: nutrient-enriched (correctly of water).
evanescent: soon disappearing, lasting a short time.
exciple: (of an apothecium) tissue or tissues characteristic of the margins adjacent to the hymenium and hypothecium. Proper exciple (excipulum proprium) - tissue at the margin of an apothecium adjacent to the hymenium and hypothecium and inside the thalline exciple when present, without photobiont cells. Thalline exciple (excipulum thallinum) - tissue at the margin of an apothecium external to proper exciple and having a structure similar to that of the vegetative thallus with photobiont cells included in it.
excluded: shut out - applied to proper or thalline margin of a discocarp when the disc swells, causing the margin to be obliterated.
exfoliating: losing outer cortex through peeling or cracking.
fabiform: bean-shaped.
farinaceous: floury, covered with mealy particles.
farinose: like grains of flour (×10 lens) - of soredia.
fascicle: a close bundle or cluster.
fastigiate: having parallel, massed upright branches (of lichen cortex, made up of parallel hyphae at right angles to axis of thallus).
faveolate: honeycombed, with shallow depressions or lacunae separated by interconnecting ridges.
fenestrate: with open areas or slits.
fibrous: of loosely woven distinct hyphae parallel with long axis of thallus - of cortex.
filamentous: thread-like, composed of filaments.
filiform: thread-like.
fimbriate: fringed, edged, delicately toothed.
fissured: cracked, split.
flabellate: fan-shaped.
flaccid: limp, flabby.
flexuous: having a wavy or zig-zag form.
foliicolous: living on leaves.
foliole: a small, dorsiventral, leaf-like appendage.
foliose: leaf-like.
friable: readily powdered, crumbling.
fruticose: shrubby, having an upright or hanging thallus.
furcate: forked.
furfuraceous: scurfy.
fuscocapitate: with a brown, inflated, usually rounded apex (usually of paraphyses).
fuscous: dusky, brown or grey-brown.
fusiform: spindle-like, narrowing at ends, wider in the middle.
gelatinous: rubbery, jelly-like.
geniculate: bent, angled, bent like a knee, often with a subtending spur.
glabrous: without hairs, smooth.
glaucous: having a bluish-grey bloom.
glebose: ± rounded elevations of thallus surface.
glebulose: having superficial rounded processes.
globose: ± spherical.
glomerule: a very dense cluster, hence glomerulate.
goniocyst: discrete, ± globular structures c. 12-40 µm diam., ecorticate granules consisting of photobiont cells intertwined and surrounded by short-celled hyphae never protected by an amorphous covering layer (in Micarea).
granular: like grains of sugar (×10 lens).
granule: a grain.
gross: coarse.
guttulate: (of spores) having one or more oil droplets inside.
gymnocarpic: (of a sporocarp) having the hymenium exposed.
gyrose: concentrically folded (of apothecial disc).
halonate: having a transparent coat around it (of the outer layer of spores).
hapteron: an aerial organ of attachment of some fruticose lichens (Alectoria, Bryoria, Usnea) formed by a secondary branch which becomes attached to substratum.
haustorium: a special hyphal branch, especially one within a living cell of the host, for absorption of nutrients.
hemiangiocarpic: (of a sporocarp) opening before quite mature.
heteromerous: having a mycobiont and photobiont components in well-marked layers, with photobiont in a ± distinct zone between upper cortex and medulla.
heterotypic synonyms: synonyms based on different nomenclatural types (taxonomic synonyms).
hersute: hairy.
holdfast: a process from the base of the thallus for attachment, often disc-like.
holotype: the one single specimen or other single element used by an author or designated by him as the nomenclatural type of a taxon.
homoiomerous: having mycobiont and photobiont components intermixed throughout thallus.
homonym: a validly published name spelt exactly like another validly published name in the same rank but based on a different nomenclatural type.
homotypic synonyms: nomenclatural synonyms.
humicolous: growing on soil.
hyaline: colourless, translucent.
hygrophanous: having a water-soaked appearance when wet.
hymenium: the spore-bearing layer of a fruit body, containing asci, spores and paraphyses.
hypha: a fungal filament.
hypophloedal: immersed in bark.
hypothallus: a layer of hyphae, often dense and ± woolly at margins or below thallus, often black or dark brown in Anzia, Pannoparmelia and the Pannariaceae.
hypothecium: fungal tissue between hymenium and exciple (if present), often pigmented, also known as subhymenium.
imbricate: overlapping.
immarginate: without a margin or well-defined edge.
immersed: embedded in the substratum.
imperforate: not perforated (of an apothecial disc).
impressed: pressed in.
incised: with cuts or tears (usually of a margin).
indeterminate: with margins not well-defined.
indigenous: natural to a country or a region, native.
inflexed: turned or bent inwards (inrolled) used of a margin of a fruit.
infundibuliform: funnel-shaped.
innate: sunken, immersed.
inspersed: interpenetrated or sprinkled with granules.
involucrellum: tissue of upper part of ascocarps (often pigmented) of some lichenised Ascomycotina.
involute: rolled inwards.
isabelline: dirty brownish-grey, yellowish or tawny.
isidiate: with isidia.
isidium: a corticate, photobiont-containing protuberance or outgrowth of the cortex which may be warty, cylindrical, clavate, scale-like, coralloid, simple or branched; pl. isidia.
isotomic: branching into two or more branches all of equal diameter.
isotype: a duplicate of a holotype, i.e., part of the single collection which includes the holotype.
labriform: lip-shaped (especially of soralia).
lacerate: cut or torn, ragged.
lacinia: a ± narrow, linear-elongate lobe of a foliose lichen.
laciniate: deeply, usually irregularly divided into narrow, ± pointed segments.
lacuna: hole, depression, gap.
lamina: a thin, flat organ or part, usually main upper surface of thallus.
laminal: on upper surface.
lateral: at or near edge, especially side or secondary branches.
lax: loosely arranged.
lecanorine: (of an apothecium) with a thalline exciple, photobiont in margin.
lecideine: (of an apothecium) with a proper exciple, without photobiont in margin.
lectotype: a type selected from the original elements (specimens or names) on which a taxon was based when the holotype was not designated at the time of publication or for so long as it is missing.
lenticular: of the shape of a ± circular biconvex lens.
leprose: having the surface dissolved into soredia, loose, powdery.
lichenicolous: growing on lichens.
lignicolous: growing on decorticated wood (lignum).
lignum: wood, usually of old wood without bark.
limiting: surrounding or setting a limit to - often used of surrounding prothallus.
limbiform: bordered.
linear: very narrow, with parallel margins.
lirella: a discocarp with a long narrow disc often branching or ± stellate cf. Graphis, Phaeographis etc.
lirellate: in the shape of a lirella.
lobate: lobed.
lobe: recognisable but not separated division, especially when rounded.
lobulate: having small lobes.
lobule: small lobe.
locule: cell or cavity.
longitudinal: lengthways.
lumen: interior of a cell.
macrolichen: larger lichens of squamulose, foliose or fruticose habit.
maculate: spotted or blotched, often caused by discontinuities in photobiont zone below upper cortex.
marginate: with a well-defined edge.
matt: with a dull surface.
mazaedium: a spore mass formed in fruits of Caliciales in which spores, generally with sterile elements, become free from the asci as a dry, loose, often dark, powdery mass on the fruiting surface.
medulla: loosely arranged layer of hyphae below the upper cortex and photobiont zone.
membranaceous: thin, ± pliant, like a membrane.
microlichen: crustose lichen, usually small.
microphylline: with minute leaflets or leafy scales.
mischoblastiomorph: specialised thick-walled spore found in Rinodina.
moniliform: bead-like.
monophyllous: consisting of a single lobe, often undulate or folded.
monopodial: of a stem in which growth is continued by the same apical growing point.
monotypic: having only one representative, i.e., a genus with only one species or a family with only one genus.
morphodeme: a morphologically differentiated group of individuals of a taxon of undetermined or no taxonomic significance.
multiseptate: with many septa.
muriform: like a wall, having transverse and longitudinal septa.
muscicolous: growing on mosses.
mycobiont: the fungal component of a lichen.
nigrescent: turning black.
nodular: with knots or lumps.
obligate: restricted to a particular host, substratum or mode of nutrition.
oblique: with sides unequal.
oblong: twice as long as wide and with rounded or truncate ends, margins parallel.
obovate: inversely ovate (narrowest at base).
obsolete: rudimentary or absent.
obtriangular: triangular but with base uppermost.
obtuse: rounded or blunt.
ochraceous: of a dull yellow colour.
omphalodise: apothecial disc with central column of sterile tissue.
opaque: dull, not translucent.
orbicular: rounded in outline, ± flat.
oriented: turned in one direction.
ostiole: a pore-like opening at the apex of a fruit of a pyrenocarpous lichen through which spores are extruded.
oval: broadly elliptic, narrowing somewhat from middle to rounded ends.
ovate: egg-shaped.
ovoid: of a solid body with an ovate outline.
pallid: pale.
palmate: radiately lobed or divided.
papilla: minute, pimple-like process; pl. papillae.
papillate: with papillae.
paraphysis: sterile, upright, basally attached fungal filament in a hymenium growing between asci; pl. paraphyses.
paraphysoid network: a network of anastomosing fungal hyphae surrounding asci in some bitunicate lichens and taking the place of paraphyses.
paraplectenchyma: tissue composed of isodiametric cells.
parasite: an organism living on or in, and obtaining its food from, its host, another living organism.
parasymbiont: an organism symbiotic with a pre-existing symbiosis (e.g., a lichenicolous fungus) not damaging its host.
parathecium: (of apothecia) the outside hyphal layer.
pectinate: comb-like, toothed.
pedicellate: stalked.
pellucid: ± transparent.
peltate: shield-like.
pendulous: hanging down from a support.
periclinal: curved in the direction of, or parallel to, the surface or the circumference.
perithecium: ± globular or flask-like fruiting body of Pyrenomycetes and angiocarpic lichens, opening by a pore at top; pl. perithecia.
phialides: conidiogenous cells producing conidia in basipetal succession through one or several openings.
photobiont: the photosynthetic partner in the lichen symbiosis, either a green alga or a member of the cyanobacteria.
photophilous: light loving.
photosymbiodeme: either of one or two morphologically different structures formed by the interaction of a single mycobiont with two different photobionts.
phyllidium: small corticate, scale-like, dorsiventral structure developed at margins or on upper surface of thallus; pl. phyllidia.
phyllocladium: small corticate thalline structure, granular, verrucose, coralloid, squamiform, digitate, peltate or foliose outgrowth, containing a green photobiont (in Argopsis and Stereocaulon); pl. phyllocladia.
phylogeny: the history of the evolution of a group.
pinnate: compound, with the parts arranged on either side of an axis, as in a feather.
placodioid: crustose at the centre but lobed and plicate at the circumference.
placodiomorph: a 2-celled spore with a thickened septum which may or may not have a pore, cf. polarilocular.
plectenchyma: a thick tissue formed by hyphae becoming twisted and fused together; paraplectenchyma - with hyphae densely coherent but with large lumina and a cellular appearance; prosoplectenchyma - with thick-walled hyphae having very minute lumina.
plicate: folded into pleats.
plurilocular: many celled.
podetium: lichenised, stem-like portion (stipe, or discopodium) bearing the hymenial discs and sometimes conidiomata in a fruticose apothecium [Ahti, Lichenologist 14: 109 (1982)].
polarilocular (polaribilocular): (of lichen ascospores) two-celled, the two lumina separated by a thick septum through which a narrow canal passes.
polymorphic: of several forms.
polytomic: dividing into many branches usually at one node.
pore: a small opening.
poriform: pore-like.
primary species: species reproducing by sexual means.
proliferating: producing offshoots or outgrowths, successive development of new parts.
propagule: a thallus fragment capable of propagating the plant (i.e., isidia, soredia, phyllidia, phyllocladia).
proper exciple: see exciple.
prosoplectenchyma: tissue composed of cells with longish lumina and in which hyphal elements are recognisable as hyphae.
prothallus: weft of fungal hyphae (white, reddish or blue-black) at margins of thallus, devoid of photobiont, often projecting beyond thallus onto substrate.
pruina: frost-like or flour-like surface covering, usually crystalline.
pruinose: with pruina.
pseudocyphella: a minute opening (round, elongate, effigurate) in the cortex exposing medullary hyphae (sometimes pigmented) but lacking specialised cells surrounding the cavity. They provide valuable taxonomic characters in several general e.g., Bryoria, Parmelia, Pseudocyphellaria; pl. pseudocyphellae.
pseudostromata: a stroma in which fungal cells and remnants of host tissue are mixed.
pubescent: downy.
pulverulent: powdery.
pulvinate: in cushions.
punctiform: dot-like.
pustulate: with pustules.
pustule: a pimple or blister-like swelling, often eroding.
pycnidium: small, globose or flask-like sporocarp in which conidia are developed; pl. pycnidia.
pyrenocarp: perithecium of pyrenomycete lichens (e.g., Verrucaria).
radiating: spreading from a central point.
reniform: kidney-shaped.
reticulum: in the form of a network, hence, reticulate.
revolute: rolled outwards or to the lower side.
rhizine: an organ of attachment, of clustered hyphae; pl. rhizines.
rimose: cracked.
rosette: radiating from a centre.
rugose: wrinkled.
rugulose: delicately wrinkled.
sac: a pouch-like structure.
saxicolous: growing on rocks or stones.
scabrid: rough.
sclerotised: hardened.
scrobiculate: coarsely pitted, faveolate.
scyphiferous: bearing scyphi (cups), used especially when apices of podetia are expanded to form cups (cf. Cladonia fimbriata).
scyphus: an expanded, cuplike structure often terminating a podetium.
secondary species: taxon reproducing mainly, or only, by vegetative means, derived from extinct or extant species reproducing mainly, or only by sexual means (primary species).
septate: divided by cross walls.
septum: cross wall.
seriate: arranged in series.
sessile: not stalked, attached directly to thallus surface (usually of apothecia).
simple: not divided into several ± similar parts, contrasted with compound.
sinuous: having rounded angles, wavy (of a margin).
sinus: a re-entering angle or recess, often between two lobes or segments.
soralium: decorticate area on a lichen thallus where soredia are located; pl. soralia.
sorediate: with soredia.
soredium: decorticate structure composed of photobiont cells and fungal hyphae, having the appearance of a powdery granule and capable of reproducing a lichen vegetatively; pl. soredia.
spathulate: with a gradually widened and flattened blunt end, as a spatula.
spine: a stout process with a sharp point.
spinose: with spines.
spinulose: with minute spines.
spore: a general term for a reproductive structure in fungi, bacteria and cryptogams, often 1-celled; the analogue of seed in phanerogams.
sporocarp: spore-producing organ; fruit body.
squamiform: scale-like.
squamule: a scale or foliole (usually corticate on both sides).
squamulose: scaly, with squamules.
stellate: star-shaped.
sterile: not producing spores or a sporocarp.
stria: a fine, longitudinal line or minute ridge, hence, striate; pl. striae.
stroma: mass or matrix of vegetative hyphae (usually black) with or without tissue of the host or substrate, sometimes Sclerotium -like in form, in or on which spores are produced, often covering a group of several ascocarps; pl. stromata.
sub: prefix meaning somewhat, slightly or not quite, e.g., subpedicellate.
substratum: the underlying layer; the base to which a plant is fixed.
subulate: tapering from a wide base to a sharp apex, ± circular in cross-section, awl-shaped.
superficial: on the surface.
symbiont: an organism that is associated with another in a mutually beneficial relationship.
symbiosis: the living together of unlike organisms in a close, long-lasting association.
sympodial: with lateral branching.
syntype: one of two or more elements cited by an author in the original place of publication of a taxon when no holotype was designated.
taxon: a taxonomic group of any rank e.g., family, genus, species, etc.
terete: circular in transverse section, either narrowly cylindrical or tapering.
terminal: borne at the end (of fruits, pycnidia etc.).
terrestrial: on or of the land or earth.
terricolous: growing on the ground.
testaceous: brownish-yellow, as of unglazed earthenware.
thalline exciple: see exciple.
thalline margin: see exciple.
thallus: the vegetative part of a lichen, ± undifferentiated plant body.
thelotremoid: having the appearance of Thelotrema, especially of fruits.
tomentose: downy.
tomentum: down, of fine, soft, silky hairs.
torus: a thickening or swelling around septum in certain thick-walled spores in Rinodina.
translucent: ± transparent.
transverse: across the width.
trichotomous: with branches in clusters of three.
truncate: ending abruptly as though with the end cut off.
tubercle: a small, wart-like process.
tuberculate: having tubercles.
tumid: swollen.
turbinate: top-shaped.
turgid: swollen, distended through internal pressure.
type: a nomenclatural type or that constituent element of a taxon to which the name of the taxon is permanently attached.
type species: the species on which the genus is based.
type specimen: the single specimen to which the name of a species or of a taxon below the rank of species is permanently attached.
umbilicate: having an umbilicus, attached at a central point.
umbilicus: a protuberance at the centre, often the point of attachment (see in Umbilicaria).
unciform: hook-shaped.
uniseriate: in one row (of spores in an ascus).
unitunicate: with one layer (of an ascus which has no inner wall).
urceolate: cup-shaped, urn-shaped, concave, hollow.
vein: strand of conducting or strengthening tissue (see Peltigera).
ventral: front, or lower surface.
vermiform: worm-like.
verruca: wart or wart-like swelling.
verrucose: warted.
zonate: ringed (especially at thallus margins) in circular lines forming pale and dark zones.
