Glossary of lichen terms

This glossary provides an overview of terms used in the description of lichens, composite organisms arising from algae or cyanobacteria living symbiotically among filaments of multiple fungus species. Erik Acharius, known as the "father of lichenology," coined many lichen terms still in use today around the turn of the 18th century. Before that, only a couple of lichen-specific terms had been proposed. Johann Dillenius introduced ' in 1742 to describe the cup-shaped structures associated with genus Cladonia, while in 1794 Michel Adanson used ' for the furrowed fruitbodies of the genus Graphis. Acharius introduced numerous terms to describe lichen structures, including, , , , , , and. In 1825, Friedrich Wallroth published the first of his multi-volume work Naturgeschichte der Flechten ("Natural History of Lichens"), in which he proposed an alternative terminology based largely on roots from the Greek language. His work, presented as an alternative to that of Acharius (of whom he was critical) was not well received, and the only terms he proposed to gain widespread acceptance were and,  and , and , the last of which remained in use until the 1960s. Until about 1850, there were 21 terms for features of the lichen thallus that remain in use today.

The increasing availability of the optical microscope as an aid to identifying and characterizing lichens led to the creation of new terms to describe structures that were previously too small to be visualized. Contributions were made by Julius von Flotow (e.g. ), Edmond Tulasne (e.g ), and William Nylander (e.g., ). Gustav Wilhelm Körber, an early proponent of using spore structure as a in lichen taxonomy, introduced, , and "polari-dyblastae", later anglicized to "polari-bilocular" and then shortened to. In the next five decades that followed, many other additions were made to the repertoire of lichen terms, subsequent to the increased understanding of lichen anatomy and physiology made possible by microscopy. For whatever reasons, there were not any new terms (still currently used) introduced from the period 1906 to 1945, when Gustaf Einar Du Rietz proposed replacing and  with  and ; all four terms remain in use. In some cases, older terminology became obsolete as better understanding of the nature of the fungal–algal relationship led to changes in their terminology. For example, after Gunnar Degelius objected to the use of for the algal partner, George Scott proposed the use of  and  for lichen components, recommendations that were generally accepted by lichenologists.

This glossary includes terms defining features of lichens unique to their composite nature, such as the major components the two major components of lichens (' and '); specialized structures in lichen physiology; descriptors of types of lichens; two- and three-dimensional shapes used to describe spores and other lichen structures; terms of position and shape; prefixes and suffixes commonly used to form lichen terms; terminology used in methods for the chemical identification of lichens; the names of 22 standard insoluble lichen pigments and their associated reference species; and "everyday" words that have a specialized meaning in lichenology. The list also includes a few historical terms that have been supplanted or are now considered obsolete. Familiarity with these terms is helpful for understanding older literature in the field.

A
a-: Also an-. A prefix meaning "not having" or "without".

ab-: A prefix meaning "positioned away from".

abortive: Referring to a developmental process in lichens where certain structures, such as spores or reproductive organs, fail to reach full development or maturity, often resulting in non-viable or malformed structures.

abraded: Having a worn or eroded surface.

accessory substance: A lichen product that is sometimes present, sometimes not present in a species. In literature, these are usually indicated with a ± symbol, e.g. ±usnic acid.

-aceae: A suffix used to indicate the taxonomic rank of family.

-aceous: A suffix used to indicate a relation or similarity to something.

acervulate: Shaped like a saucer. acicular: Also aciculiform. Needle-shaped; long and slender with a taper at both ends. Typically used to describe spore shape.

acro-: Also acr-. A prefix used to indicate that something is positioned on the end or the upper part.

acrogenous: Developing on the apex of a structure.

acroton: A needle-shaped structure with lateral branches.

actinolichen: A lichen-like association between an actinobacterium (Streptomyces) and a green alga (Chlorella xantha).

acuminate: Gradually tapering to a point.

ad-: A prefix used to indicate positioning at the end or on an extremity.

adglutinated: Stuck together.

adnate: Having a tight attachment to a surface.

adventive branching: Referring to, a branching pattern that is unusual or abnormal, like that which sometimes occurs after the original branches are damaged in Cladonia.

-al: A suffix used to indicate a relation to, or having the form and character of something.

alectorioid lichen: An informal growth form category used for lichens that are, typically with beard-like that are or clustered; this group of features is characteristic of lichens now classified in the genera Alectoria, Bryoria, Oropogon, Pseudephebe, and Sulcaria.

algal layer: Also photobiont layer. The layer of tissue in a lichen that contains the ; it is typically located between the upper  and the.

alcobiosis: Plural alcobioses. A form of symbiosis involving algae and corticioid fungi, primarily occurring on bark and wood surfaces. In this relationship, algae form a layer beneath the fungal basidiomata—structures akin to the in lichens. This association, unlike in lichens, does not render the fungal partner nutritionally dependent on the algae, thus all involved fungal species are capable of surviving without the algal partner. Alcobiosis represents a diverse interaction, seen in various stages of coevolution, involving multiple species across the Agaricomycetes fungal group and three algal species from the class Trebouxiophyceae.

alveolate: Used to describe a surface that has a pattern similar to a honeycomb (i.e. with more or less 6-sided hollows), where the surface appears to be composed of small pits or cavities like alveoli. Compare:,,.

amphi-: A prefix used to indicate on both sides, or on all sides.

amphithecium: Plural amphithecia. The of a ; equivalent to the. The amphithecium usually contains algal cells. The term was coined by Wilhelm Körber in 1855, but languished in obscurity until 1898, when Otto Darbishire used it in a monograph of the genus Roccella.

ampliotremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Ampliotremoid lichens have prominent apothecia with wide pores, black walls (viewed in microscopic section), and a smooth, more or less shiny thallus; this morphotype occurs in the genera Ampliotrema and Ocellularia.

ampulliform: Bottle-shaped, i.e., with a narrow neck and swollen base.

amyloid:

Turn a purple or blue color upon reaction with Melzer's reagent.

anisotomic: Also anisotomous. Having branches of unequal length; if the branching is anisotomic, one branch is typically stouter than the other, forming a main stem while the other appears like a lateral branch, as in the species Alectoria ochroleuca. Contrast:.

annulotremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Annulotremoid lichens have prominent apothecia with wide pores, pores with an inner ring, and a smooth, more or less shiny thallus; this morphotype occurs in the genera Myriotrema and Thelotrema.

anticlinal: Perpendicular to a surface; used to refer to alignment.

apical: Located at the highest point (the apex), the tip, or the end of something.

apiculate: Having a short projection (an apicule) at one end; typically used to describe spore morphology.

apothecium: Plural apothecia. A type of ascocarp that is open, saucer-shaped or cup-shaped, and in which the is exposed at maturity. The term was first used by Erik Acharius in 1803.

appressed: Lying flat; flattened down on a surface.

arachnoid: Also araneose, araneous. Having a cobweb-like form, like that of the irregularly oriented and loosely interwoven of the ry layer of some lichens.

Arceutina-yellow: A pale yellow insoluble lichen pigment, associated with the reference species Bacidia arceutina.

arcuate: A shape or structure that is curved or arched like a bow.

ardella: Plural ardelae. A type of, typical of lichens in the family Arthoniaceae, which is small and round. Elongated ardellae are called. The term was first used by William Allport Leighton in 1854, who described an ardella as resembling a "sprinkled spot". areola: Plural areolae. A small area, typically rounded to polygonal or irregular in shape, and often with a distinct texture. In a lichen thallus, the areolae are often separated from the rest of the thallus by fissures or cracks.

areolate: Also areolar. The condition of being made of or covered with, such as the s.

Arnoldiana-brown: A reddish-brown insoluble lichen pigment, associated with the reference species Bacidina arnoldiana.

ascigerous: Having.

asco-: A prefix meaning "".

ascocarp:

Also ascoma, plural ascomata. The fruiting body of an ascomycete fungus, containing the and.

ascoconidium: Plural ascoconidia. A that is formed directly from an.

ascogenous: Also ascogenic. Producing or supporting the growth of an.

ascolichen: A lichen in which the fungal partner (the ) is a member of the Ascomycota. About 98% of lichens are ascolichens. See related:. ascospore: A sexual, haploid spore produced in an.

ascus:

Plural asci. A sexual, fungal spore-bearing structure, typically sac-like.

aseptate: Lacking.

aspicilioid: Referring to that are (at least initially) partially to completely immersed in the.

astomate: Also astomous. Lacking an opening, or ostiole.

astrothelioid: Referring to a type of ascospore morphology prevalent in the genus Astrothelium; characterized by thick-walled and diamond-shaped.

-ate: A suffix, added to nouns, used to indicate having the appearance or characteristics of that noun.

Atra-brown: A matt brown insoluble lichen pigment, associated with the reference species Opegrapha atra.

Atra-red: A dark red insoluble lichen pigment, associated with the reference species Tephromela atra.

aulaxinoid: A morphotype of lichens used to describe characteristics of  and  structure. This term refers to a morphotype of lichen where the apothecia are partially embedded and partially protruding, having a dark, hardened that forms irregular cracks. This morphotype is uniquely seen in "Thelotrema" dislaceratum, a species with uncertain taxonomic placement.

B
bacillar: Also bacilar, bacilliform, baculate, baculiform. Shaped like a small rod, typically with a length:width ratio of about 3:1.

Bagliettoana-brown: A pale to brownish-green insoluble lichen pigment, associated with the reference species Bacidia bagliettoana.

basidiolichen:

A lichen in which the fungal partner (the ) is a member of the Basidiomycota. About 0.4% of lichens are basidiolichens. See related:.

bi-: A prefix meaning two or twice.

biatorine: A type of with a soft, light-colored (not ) margin, like those in genus Biatorella.

bifurcate: Divided into two parts or branches. See related:.

bifusiform: Referring to a shape or structure that is elongated and tapers at both ends, with a constriction or narrowing in the middle. See related:.

biguttulate: Containing two oil droplets (guttules).

bilabiate: Referring to a type of in which the splits at the top and exposes the  by forming an opening with a lip on each side; bilabiate asci occur in the genus Pertusaria.

bipartite lichen: A lichen with a two-partner symbiotic association of and. See related:.

bipolar lichen: A lichen that occurs in polar areas of both the Northern and Southern Hemispheres.

biseriate: Lined up in two parallel rows.

bitunicate: Also defined: endotunica, ectotunica. A type of that has two functional layers, the internal layer, the endotunica, and the external layer, the ectotunica. Bitunicate asci are characteristic of the historical class Loculoascomycetes.

blastidium: Plural blastidia. A rounded -like propagule containing and, produced from the margin by budding; subsequent blastidia are formed from the tips of the previous ones. The term was introduced by Josef Poelt in 1980.

borderline lichen: A symbiotic interaction where either green algae or cyanobacteria are enveloped by fungal tissue, but without forming the discrete layers that occur in most lichens.

botryose: Resembling rounded, bead-like structures or clusters resembling grapes. branch: A lateral growth of the main stem of a thallus in ; various features of a branch are diagnostically valuable in distinguishing species.

branchlet: A small.

bryophilous lichen:

Also defined: hepaticolous lichen; muscicolous lichen. A lichen that grows on a moss or liverwort – i.e. on a bryophyte. A hepaticolous lichen is found only on liverworts, while a muscicolous lichen is found only on mosses.

bullate: Having blister-like or bubble-like swellings on a surface.

byssoid: Having the texture of cotton; made of loosely intertwined. See related:,.

C
C test: A that uses a solution of bleach (sodium hypochlorite) as a reagent to check for the presence of certain lichen products.

Caesiocinerea-brown: An insoluble lichen pigment, colored olive to sordid green to black, associated with the reference species Aspicilia caesiocinerea.

caesious: A bluish-gray or bluish-green coloration.

caespitose: Also caespitous, cespitose. Growing in dense clusters or tufts, often used to describe fungi that arise from a common base or grow closely together without fusing.

calcicolous lichen: A lichen that grows on substrates rich in calcium carbonate, such as calcareous or gypseous rocks or soil.

calcifuge: A lichen that prefers acidic soils and tends to avoid, or is intolerant of, alkaline conditions often associated with high calcium carbonate content; opposite of.

campylidium: Plural campylidia. A helmet-shaped conidioma. They are found in several genera of tropical s, such as Badimia, Loflammia, and Sporopodium. The term was introduced by Johannes Müller Argoviensis in 1881. canaliculate: Having one or more longitudinal grooves or channels.

capitate: Having a well-formed head, usually spherical or hemispherical in shape. See related:.

capitulum: Plural capitula; also sphaeridium/sphaeridia. A more-or-less spherical or cup-shaped on the top of a stalk, found in the genera Calicium and Chaenotheca. See related:.

carbonized: Also carbonised, carbonaceous. Blackened and brittle tissue resulting from the accumulation of pigments.

cariose: A lichen thallus or structure that is cracked, split, spongy, or otherwise decayed or in a state of disintegration.

cartilaginous: Also cartilagineus. A term used to describe the texture of certain parts of a lichen. Cartilaginous structures have a texture similar to animal cartilage – firm but somewhat pliable, not brittle or soft.

cataphysis: See. catapyrenioid lichen: A member of the Verrucariaceae that is, has simple ascospores (without any ), and lacks algae in the ; historically classified in the genus Catapyrenium.

catenate: Arranged in chains or end-to-end; refers to spore arrangement.

caudate: Having a tail or tail-like appendage.

cavernula: Plural cavernulae. A small hollow or cavity; used to refer to the holes in the lower of the genus Cavernularia.

central axis: Also chondroid axis. The cartilage-like central core in the branches of, made of longitudinally arranged. The term "chondroid axis" was first used by William Nylander in 1858.

cephalodium:

Plural cephalodia. A small gall-like structure that contains cyanobacteria, found in some lichens. These structures can be located on the lichen's upper or lower surface, or within the thallus itself. These structures are found in most lichens that contain both algal and cyanobacterial. The term was first used by Erik Acharius in 1803.

cerebriform: Having a surface texture that is deeply wrinkled or convoluted in a manner resembling the structure of a brain. The term is used to characterize the appearance of certain lichens with a complex, highly folded.

cetrarioid lichen: An informal growth form category used for lichens with erect,, and and pycnidia on the margins of the lobes; characteristic of lichens previously classified in the genus Cetraria (in the broad sense).

chalaroplectenchyma: Plural chalaroplectenchymata. A type of comprising loosely interwoven with holes; found in the  of some lichens.

character: A distinguishing feature that is characteristic for an organism; equivalent to phenotypic trait.

chasmoendolith: Also chasmoendolithic. A type of organism, typically a lichen or fungus, that lives within cracks and fissures of rocks. See related:.

checklist: A list of all of the species (sometimes including subspecies, varieties and forms) that occur within a particular region.

chemosyndrome: A set of lichen products produced by a species; this typically includes one or more major compounds and a set of biosynthetically related minor compounds.

chemotype:

Chemically differing types of a species with the same morphological characteristics, of no or unknown taxonomic significance. chlorococcoid: A term describing green algae with a shape.

chondroid axis: See.

chroodiscoid: A morphotype of lichens used to describe characteristics of  and  structure. Chroodiscoid lichens have open apothecia with recurved and a smooth and more or less shiny thallus; this morphotype occurs in the genera Acanthotrema and Chapsa.

cilium: Plural cilia. Fine, hair-like outgrowths of the or, common in and  lichens.

ciliate: Having.

Cinereorufa-green: A green to turquoise insoluble lichen pigment, associated with the reference species Schaereria cinereorufa.

citriform: A shape or form that resembles a lemon or citrus fruit. The term is used to describe structures, particularly or other components of a lichen, that have an elongated, oval shape with tapered ends.

CK test: A seldom-used performed with an application of followed immediately by.

cladoniiform lichen: Also cladoniform lichen, dimorphic lichen. Also defined: primary thallus and secondary thallus. A lichen with a two-fold growth form that includes both a,, or form and a form; the  differentiates into both horizontal (primary thallus) and vertical (secondary thallus, or ) structures. Cladoniiform lichens occur in the families Cladoniaceae and Baeomycetaceae.

clavate: Also claviform. A shape resembling a club, broader at one end and tapering towards the other; typically used to refer to and.

clypeate: See.

coalescent: Also coalesced. Growing together to form one mass.

coccoid: Spherical; resembling a coccus.

complanate: Flat and smooth.

concolorous: Having the same color throughout.

confervoid: Appearing loosely filamentous or thread-like.

confluent: Joining together, blending into one. conidiophore: A specialized structure that produces and bears.

conidium:

Plural conidia. Also conidiospore. A fungal asexual spore produced by mitosis in specialized structures such as pycnidia and campylidia.

conglutinate: Also conglutinated. Stuck or glued together; usually applied to or.

consoredium: An aggregation or cluster of incompletely separated. The term was introduced by Tor Tønsberg in 1992.

coralloid: Highly branched, similar to a coral in form.

coriacellate: With a somewhat leathery texture.

coriaceous: With a leathery texture.

corrugate: Wrinkled; with alternate furrows and ridges.

cortex:

The lichen's outer layer(s), made up of tightly woven fungal filaments.

corticate: Having a.

corticolous lichen:

A lichen that grows on bark.

crateriform: Shaped like a bowl or a crater; hemispherical and concave.

crenate: Having a scalloped or round-toothed edge.

crenulate: Having a finely scalloped edge; similar to crenate but with smaller notches.

cruentodiscoid: A morphotype of lichens used to describe characteristics of  and  morphology. Cruentodiscoid lichens have open apothecia with erect and a pigmented, and a smooth, more or less shiny thallus; this morphotype occurs in the genus Chapsa.

crustose:

A form of growth where the lichen is pressed so tightly against the substrate upon which it grows that it is impossible to remove without destroying either it or part of the substrate. Crustose lichens have a only on their upper surface.

cryptoendolith: Also cryptoendolithic. A type of organism, particularly certain lichens and fungi, that live inside rocks or in the microscopic spaces within the mineral grains of rocks. See related:.

cryptolecanorine: A apothecium that is mostly immersed in the, with an indistinct.

cryptothalline: Pertaining to a type of lichen that is largely hidden or immersed within the, making it barely visible or entirely concealed. See related:, ,. Contrast:.

crystallocumuli: Punctiform or elongated agglomerations of oxalate crystals that are dispersed over the ; associated with the family Trichotheliaceae. See related:.

crystallostratum: A continuous layer of oxalate crystals embedded in the thallus, associated with the family Trichotheliaceae. The term was introduced by Josef Hafellner and Klaus Kalb in 1995. See related:.

cuculate: Hood-shaped.

cupulate: Cup-shaped.

cuneate: Also cuneiform. Wedge-shaped; with one end thinner than the other.

cyanolichen:

A lichen in which the is a cyanobacteria. cyphella: Plural cyphellae. A sharply defined, rounded, ovate, or shapeless pore in the lower surface (typically the lower ), which is lined with a "pseudocortex" made of loosely connected, non-gelatinized (often with globular cells, formed from the ) and bounded by a pale ring; known to occur in the genera Sticta and Oropogon. The term was first used by Erik Acharius in 1799.

D
dactyloid: See.

decorticate: Having had a that has been removed or disintegrated. See related:.

decumbent: Lying flat on a with the edges curled up.

dendritic: Irregularly branched, like a tree.

dentate: Having a toothlike or serrated edge.

denticulate: Having small tooth-like projections or serrations along the edge.

dextrinoid: A chemical property referring to a substance's ability to turn reddish-brown in the presence of Melzer's reagent or iodine due to the presence of dextrins. This color reaction is also called hemiamyloid or pseudoamyloid.

determinate: Having well-defined or clearly marked edges. Contrast:.

diagnosis: A brief account of a taxon describing the essential characteristics that distinguish it from its relatives.

diahypha: Plural diahyphae. A type of formed from that split  in several branches, with prominent constrictions at the, resulting in the appearance of chain links; found in the family Gomphillaceae.

diaspore:

A sexual or asexual propagule used for dispersal; in lichens, usually used to refer to and.

dichotomous: Branching into two equal parts. See related:. Contrast:.

diffuse: Spread out and scattered without any definite boundary or margin. See related:. Contrast:. digitate: Also dactyloid, dactyliform, digitiform. Having finger-like outgrowths.

dimidiate: A structure that is divided into two unequal halves, often appearing as half-circles; in lichenology the term is often applied to the.

dimorphic lichen: See.

discoid: Also: disciform. A shape that is flat and circular, resembling a disk. In lichenology, this term often refers to the of lichens that have a flat, disk-like shape.

discolichen: A grouping of s that produce -like, somewhat analogous to the fungal Discomycetes; the term applies to the majority of lichens.

discothecium: Plural discothecia. The fruiting body of certain types of lichens, with cylindrical,. It is distinguished from a hysterothecium, which is another type of fruiting body, by not opening through a slit but by expanding the to weather or push apart the typically thin upper stromatal layer. The term was introduced by Richard P. Korf in 1962.

disk: Also: disc. The curved or flat upper surface of the in an, often pigmented and surrounded by a margin or rim.

distal: Positioned away from a point of origin or from the center of a body.

distoseptum: Plural distosepta. A type of found in some and, which is located within but distinct from the outer wall and surrounds the internal. Structures with distosepta are said to be distoseptate.

doliiform: Barrel-shaped.

dome: See.

E
e-: A prefix meaning "not having" or "without".

eccentric: Also excentric. Displaced from the center.

echinate: Covered with spines or bristles.

echinulate: Covered with small spines or bristles.

ecorticate: Lacking bark, or a.

ectal excipulum: See.

ecto-: A prefix meaning "outside" or "outer".

ectotunica: See. effigurate: Referring to, lichens with areoles that are extended and arranged radially; also defined more generally as "obscurely lobed".

effuse: Spread out and flat; used to describe the of some s lacking a well-defined outline. Contrast:.

eguttulate: Lacking oil droplets (guttules).

Elachista-brown: A fuscous brown insoluble lichen pigment, associated with the reference species Micarea elachista.

ellipsoid:

An object appearing approximately elliptical in longitudinal section and circular in cross-section; often used to refer to spore shape.

emarginate: Also immarginate. Lacking a well-defined border or edge. When referring to, it means lacking a, or a raised. See related:,.

endo-: Also end-, ecto-, ect-. A prefix meaning "inside" or "inner".

endocarpic: Also endocarpinoid. Referring to lichens with that are sunk into the tissues of the, such as seen in the genera Endocarpon and Dermatocarpon.

endolichenic fungus: A fungus that lives within the of a lichen without producing any visible symptoms of disease; these fungi are transmitted horizontally. endolith: Also endolithic. A crustose lichen that grows in the interior of rocks (under and around the rock crystals), typically with little or no visible on the outer rock surface. Contrast:. See related:,,.

endophloeodal: Also endophloeodic, endophloeic, endophloic. Refers to s whose are more or less immersed in tree bark. Contrast:.

endotunica: See.

entire: Refers to margins or edges of lichen structures (such as,, or ) that are smooth and unbroken, without any notches, teeth, or irregularities.

epi-: Also ep-. A prefix meaning "upon" or "above".

epibryophyllous: Also epibryophytic. Referring to organisms, particularly lichens or fungi, that grow on the surface of mosses (bryophytes).

epicortex: A thin layer of polysaccharides that is present on the surface of the in some lichens.

epihymenium: A thin tissue layer of interwoven situated directly above the, which can contain pigments and sometimes plays a role in the coloration of the lichen. Compare:.

epilithic: Also petricolous, rupicolous,. A crustose lichen that grows on the surface of rocks. Contrast:.

epinecral layer: A layer of dead with indistinct found near the  and above the algal layer. See related:.

epiphloedal: Also epiphloeodal, epiphloeodic, epiphloic. Growing on the surface of bark. Contrast:.

epipsamma: A region of -like, often pigmented material, that permeates the upper parts of but is distinct from the ; associated with the genus Rhizocarpon. The term was coined by Josef Poelt in 1969.

epithecium: Plural epithecia. Tissue on the top of an (above the ) formed from the coalesced tips of projecting. The term was first used by Julius von Flotow in 1851.

epruinose: Lacking.

erumpent: Also perrumpent. Breaking through a surface. A more precise definition has been suggested by Aptroot and Lücking, who propose that the term applies to and that are more than 1/2 to 3/4 above the level of the.

esorediate: Also esorediose. Lacking.

eucortex: Plural eucortices or eucortexes. A made of well-differentiated tissue. Another sense of the term, used by Josef Poelt, refers to cortical tissue made entirely of fungal cells originating from a cambium-like tissue layer in or above the. The term eucortex was first used by Gunnar Degelius in 1954.

euendolith: Also euendolithic. A type of organism, often a lichen or microbe, that actively bores into and resides within the mineral matrix of rocks or other hard substrates. See related:.

euthalline: Describing a type of lichen that is clearly visible and well-developed on the surface of the. See related:. Contrast:.

evanescent: Lasting a short time.

excipulum thallinum: See.

exsiccatum:

Plural exsiccata, exsiccatae, exsiccati. A dried and labeled herbarium specimen, often part of a numbered set.

excipulum: Also exciple. Plural excipula. The cup-shaped or ring-shaped layer of tissue supporting the in an ; this tissue sometimes develops into a distinct margin, as in the apothecia. See related:,.

F
fabiform: Bean-shaped.

facultatively lichenicolous: A fungus species that is commonly collected from lichens (i.e., it is ) but is also capable of living on non-lichen s.

falcate: Also falciform, lunate. Thin and curved with pointed ends, like a scythe or sickle.

farinaceous: Also farinose. Covered with a mealy powder; the of Cladonia deformis are covered with farinose.

fasciate: Also fasciated. Having a ribbon-like or band-like structure, such as the of some lichens.

fascicle: A bundle or cluster; can be used to refer to,, , etc.

fasciculate: Arranged in bundles or clusters.

fastigiate cortex: A region of the where the are aligned perpendicularly to the main axis of the. The term was first used by Auguste-Marie Hue in 1906. See related:.

faveolate: Pitted with large, deep depressions that are narrowly separated by sharp ridges. Compare:,,.

fenestrate: Having perforations or gaps arranged in a regular pattern.

-fer: Also -ferous. A suffix meaning to carry or produce.

fibercle: A scar on lichen thalli resulting from the breaking of attached fibrils; associated with the genus Usnea.

fibril: A tiny fibre; when referring to the genus Usnea, it means short branches that are perpendicular to the main branches.

fibrillose: Covered with silky fibres.

filiform: Thread-like; fine and slender.

fimbriate: Having hairs or fibres on the margin. See related:,.

fimbrillate: Delicately ; bordered with minute fringe.

fissitunicate: A form of in which the flexible layers of the inner wall (the ) and the more rigid layers of the outer wall (the ) are physically separated; as a consequence, the inner walls extend past the outer walls before the spores are released.

fissurine: Also fissurate. A term used characterize a structure or surface displaying a pattern of narrow, elongated cracks or fissures.

fissurinoid: A morphotype of lichens used to describe characteristics of  and  structure. This morphotype is somewhat similar to the, but it differentiates by the way the apothecia open through irregular thallus cracks, finally resembling chroodiscoid apothecia. It often has a unique elongated form at maturity and can be seen in species such as Acanthotrema brasilianum and various Chapsa species.

fistular: Also fistulose. Tubular and hollow.

flabellate: Also flabelliform. Fan-shaped.

flexuous: Also flexuose. Bending or curving in alternate directions, like a zigzag.

floccose: Having the texture of loose cotton or wool.

foliicolous lichen:

Also epiphyllous lichen. A lichen that grows on a plant leaf.

foliole: A small leaf-like outgrowth from the of a.

foliose:

Leaf-like; a type of lichen comprising numerous small leafy, often extending in a roughly circular pattern from a center of growth, on a lower that is attached to the  by  or at a base.

forage lichen: Lichens that serve as important food sources for fauna. For example, species from the genera Alectoria, Bryoria, and Cladonia are winter forage lichens for caribou in northern North America.

foveate: Having pits or perforations.

foveolate: Pitted with small, deep depressions that are widely separated by a more or less even. Compare:,.

friable:

Readily crumbled or pulverized.

fruit wart: An informal term for a type of that has ( or ) characteristics.

fruticose:

A lichen with a shrub-like or hairy attached to the at a single point.

fruticulose: Also fruticulous. A smaller version of a. See related:.

fulvous: An yellow-brown or tawny color.

funiculus: See.

funoid: Made of fibers or rope-like strands.

furcate: Forked.

furfuraceous: Covered with small flakes.

fuscocapitate: A term used to describe structures, such as hairs or other appendages, that have a dark or dusky-colored rounded tip or head.

fuscous: A dark, grayish-brown or grayish-black color.

fusiform:

Tapered at both ends, like a spindle.

fuzzy coat: The outer gelatinous layer, also known as the g-layer, found on the exterior of an, often exhibiting a gelatinous consistency and staining blue in iodine. Typically present in all asci, the fuzzy coat usually forms a thin layer along the ascus sides but may also appear as an apically thickened cap.

G
gelatinous lichen: A rubbery or jelly-like lichen with a cyanobacterial. See related:.

geniculate: Having a knee-like bend; applied to parts of and where a bend forms due to directional changes during growth.

glabrescent: Becoming.

glabrous: Lacking hair or bristles; smooth.

glaucescentoid: A morphotype of lichens used to describe characteristics of  and  morphology. Glaucescentoid lichens have open apothecia with erect lobules, and a rough thallus containing crystals; this morphotype occurs in the species Leucodecton glaucescens.

glaucophaenoid: A morphotype of lichens used to describe characteristics of  and  morphology. Glaucophaenoid lichens have prominent apothecia with wide pores, pale walls (viewed in microscopic section), and a smooth and more or less shiny thallus; this morphotype occurs in the genus Myriotrema.

gleolichen: Also gloeolichen. A lichen with algal cells belonging to the genera Chroococcus, Gleocapsa, or other Chlorococcales; these algae have a mucilaginous capsule.

globose: Also globoid, globular. Approximately spherical.

glomerule: Plural glomeruli. A dense clump or aggregate of cells or spores. glypholecideous: Also glypholecine. Having especially labyrinth-like, as in the genus Glypholecia.

gonidial layer: A now-obsolete, historical term for the algal layer in a lichen.

gonidium: Plural gonidia. A now-obsolete, historical term for a lichen. The term was first used by Friedrich Wallroth in 1825, and supplanted in the 1960s.

gonimium: Plural gonimia. A now-obsolete, historical term for a lichen. goniocyst: A propagule found in some tropical lichens that consists of  cells wrapped in  ; it is similar in form to, but it is made in a special organ called a. The term goniocyst was introduced by Johannes M. Norman in 1872.

goniocystangium: Plural goniocystangia. A special organ, found in some tropical lichens, that produces s.

granular: Also granulate, granulose. Made of small particles (granules).

granule: An irregularly rounded grain-like particle.

graphid: A lichen with in the form of, as in the genus Graphis.

growth form:

A term for the general appearance (the habit) of a lichen.

grumose: Having a or crumbly texture or appearance.

guttulate: Referring to structures containing small oil droplets (guttules); often used to describe spores. More precisely, spores can be described as,, , or.

gyrodisc: An with concentric circles on the upper surface, as seen in the species Umbilicaria cylindrica. The term was first used by George Llano in 1950.

gyrose: Also gyrate. Curved backward and forward; with folds and undulations.

gyrotremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Gyrotremoid lichens have open apothecia with recurved, a that is pigmented with concentric rings, and a smooth, more or less shiny thallus; this morphotype occurs in the genus Gyrotrema.

H
hafter: A flattened attachment point formed through direct contact of a lichen to its ; associated with and  lichens that lack other attachment organs, such as Hypogymnia.

halonate: Also defined: halo. Referring to a spore that is surrounded by a transparent outer layer or a gelatinous, translucent sheath. This sheath is readily observed when the spore is stained with India ink, as the ink does not penetrate the mucilage of the sheath, creating a light-transparent halo that is visible against a blackened background.

hamathecium: Also interascal tissue. A term describing the and tissues that exist between the ; examples include paraphyses,,, , and.

hapteron: Also hapter, plural haptera. An aerial attachment organ, made of highly adhesive, that helps secure a to its substrate in some, such as Cladonia, Ramalina, and Usnea.

hemiamyloid: See.

hepaticolous lichen: See.

Hertelii-green: A green to turquoise insoluble lichen pigment, associated with the reference species Biatora hertelii.

hetero-: Also heter-. A prefix meaning "other" or "different".

heterocyst: A specialized type of cell found in some cyanobacteria; heterocysts are thought to be involved in the fixation of nitrogen by the lichen thallus, as well as in the multiplication of cyanobacteria.

heteromerous: A lichen that is organized into discrete layers or strata; the term applies to the majority of,, and lichens. hirsute: Also hispid, strigose. Covered with hairs.

holdfast:

A part of the, usually near the base, that is adapted for attachment to the growing surface.

homo-: A prefix meaning "analogous", "similar", or "same".

homoiomerous: A lichen in which the partner (typically from genus Nostoc) is evenly distributed throughout the ; characteristic of s such as Collema and Leptogium. The term was first used by Friedrich Wallroth in 1825.

hormocyst: Also hormocyte. Also defined: hormocystangium, plural hormocystangia. An asexual propagule, produced in a cup-shaped structure called the, comprising heavy, gelatinous fungal enclosing a few cells; these structures occur in some s in the family Collemataceae. Both terms, hormocyst and hormocystangium, were introduced by Gunnar Degelius in 1945. According to one source, hormocyte and hormocytangium (spelled without the "s") are more accurate terms, because the cells (indicated by the ending -cyte) are not sexual propagules (which is implied by the ending -cyst).

hyaline:

Transparent and colorless.

hymenium:

The fertile tissue of the fruit body where spores are produced.

hypha:

Plural hyphae. A microscopic fungus filament comprising one or more cells surrounded by a tubular cell wall.

hyphophore: An erect, stalked,, asexual spore-producing organ (sporophore) associated with tropical.

Hypnorum-blue: A dark blue to black insoluble lichen pigment, associated with the reference species Lecidea hypnorum.

hypo-: Also hyp-. A prefix meaning "beneath" or "under".

hypogymnioid lichen: An informal growth form category used for lichens with that are swollen, inflated, and lacking, combined with the presence of the substances atranorin in the upper  and physodic acid in the. These features are characteristic of lichens in the genera Hypogymnia and Menegazzia.

hyponecral layer: A layer of dead with indistinct found near the  and below the algal layer. See related:.

hypophloeodic: Also hypophloeodal. Refers to lichens whose are almost immersed in tree bark; characteristic of several species in the Thelenellaceae. The term was first used by Friedrich Wallroth in 1825. See related:.

hypothallus: The first to grow in a ; often blackish in color, it is where originate. The term was first used by Elias Fries in 1831.

hypothecium: Plural hypothecia. A layer of tissue under the in an ; also used to refer more generally to all tissues under the. The term was first used by Carl von Martius in 1828.

hysterothecia: See.

I
I: An abbreviation for a solution of iodine crystals dissolved in aqueous potassium iodide and diluted to a light brown color.

imbricate: Also imbricated. Overlapping partially, like roof tiles; used to refer to lichen structures like,, , and.

immaculate: Without spots.

immarginate: See.

immersed: Embedded or sunken into the surface; in lichens, often used to describe. A more precise definition has been suggested by Aptroot and Lücking, who propose that the term applies to and that are more than 3/4 beneath the level of the.

incertae sedis:

A term used for a taxon of uncertain, doubtful, or unknown classification.

imperforate: Lacking an opening.

inflated: Swollen or blown up, and hollow, like the of genus Hypogymnia.

inspersed: Also defined: inspersion. Also inspers, interspersed. Terms used to describe the presence of minute, scattered or  within a tissue, typically observed in section with a compound microscope. An inspersion refers to the degree of obstruction caused by the sprinkling of small particles within different sections of a given structure.

Intrusa-yellow: A yellow insoluble lichen pigment, associated with the reference species Carbonea intrusa.

involucrellum: Plural involucrellae. The tissue of the outer part of a, often pigmented, surrounding the.

isidiate: Having.

isidiomorph: A structure that resembles an, but is formed as an outgrowth of the rather than the ; associated with of species in the genus Usnea.

isidiotremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Isidiotremoid lichens lack apothecia and have, and a smooth, more or less shiny thallus; this morphotype occurs in the genera Myriotrema and Ocellularia.

isidium:

Plural isidia. A propagule that is an outgrowth of the ; it has a and contains cells. The term was first used in the sense it is used now by Georg Meyer in 1825, and adopted by Elias Fries in 1831.

isodiametric: Having roughly equal dimensions in all directions, resulting in a roughly spherical or cube-like shape; often used to describe cells that are not elongated or flattened but maintain a uniform size across their width, height, and depth.

isotomic: Having branches of equal length.

isthmus: The narrow middle portion between the two of a spore.

J
juga: Plural jugae. A tiny structure made of tissue, visible as a black dot, line, or ridge, on or in a ; associated with the genus Verrucaria.

K
K test: A that uses a 10–25% solution of potassium hydroxide as a reagent to check for the presence of certain lichen products.

KC test: A performed with an application of followed immediately by.

L
labriform: Shaped like or resembling a lip.

lacinia: Plural laciniae. A narrow of a lichen.

laciniate: Also laciniated. Referring to an edge divided into delicate bands or narrow lobes.

Lactophenol cotton blue:

Also LCB. A histological stain commonly used to prepare semi-permanent slides. With this reagent, fungal stain blue, and algal cells stain deep blue to blue-green.

lacunose: Also lacunar, lacunous. A texture that appears pitted or containing gaps or holes, giving it a somewhat rough or uneven appearance.

lageniform: Flask-shaped; with a swollen base tapering to a narrow top.

lamella: Plural lamellae. In the genus Umbilicaria, lamellae are flattened plate- or strap-like structures that project downward from the undersurface.

lamelloid: A morphotype of lichens used to describe characteristics of  and  structure. In this, apothecia are noticeably protruding and organized into several distinct, concentric rows of. This morphotype is seen in species like Chapsa lamellifera.

laminal: All over the thallus surface, rather than in the center or on the margins. Contrast:.



Laurocerasi-brown: A reddish- or purplish-brown insoluble lichen pigment, associated with the reference species Bacidia laurocerasi.

lax: Loose, loosely woven, not compact; like the in the.

lecanorine: Also lecanoroid. An in which the is surrounded by a pale thalline margin, which has both algal and fungal cells, as in the genus Lecanora. The term is also used more generally to refer to s of the order Lecanorales that have rounded apothecia with thick, protruding margins.

lecideine: Also lecideoid. An in which the lacks a thalline margin, as in the genus Lecidea. The term is also used more generally to refer to apothecia with a blackened (carbonaeous) ring and a blackish.

leiodisk: Also leiodisc. A of an that is smooth and without folds or protrusions. The term was introduced by George Llano in 1950.

lepadinoid: A morphotype of lichens used to describe characteristics of  and  structure. This morphotype describes lichens where apothecia are semi-embedded to prominently protruding and have a free and a distinctive double margin. The bulges and remains whole, while the excipulum is prominent and wavy-lobed. Fibrillithecis halei, Leucodecton occultum, Myriotrema costaricense, and Thelotrema are examples of this morphotype.

leprocarpoid: A morphotype of lichens used to describe characteristics of  and  morphology. Leprocarpoid lichens have open apothecia with erect lobules and a mealy and more or less thallus; this morphotype occurs in the genus Chapsa. leprose lichen:

A lichen made entirely of, lacking a.

Leptocline-brown: A dark red-brown insoluble lichen pigment, associated with the reference species Buellia leptocline.

Leptoclinoides-brown: A brown insoluble lichen pigment, associated with the reference species Hafellia leptoclinoides.

leptotremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Leptotremoid lichens have immersed apothecia with small pores, and a rough thallus containing crystals; this morphotype occurs in the genus Leptotrema.

leucodectonoid: A morphotype of lichens used to describe characteristics of  and  morphology. Leucodectonoid lichens have closed apothecia with tiny pores, and a rough thallus containing crystals; this morphotype occurs in the genus Leucodecton.

lichen desert: A zone around a city or air pollution source that is devoid of and lichens.

Lichenes: The name of a historical class that contained all of the lichen-forming fungi. This name was used when it was still erroneously believed that these fungi were quite separate from the non lichen-forming fungi; now obsolete.

lichenicolous lichen:

A lichen that grows on another lichen.

lichenin:

Also lichenan. A polymer of glucose that occurs in the cell walls of the of many species of lichen-forming fungi. It forms a red color when stained with iodine.

lichenometry:

A dating technique that measures crustose lichen growth to estimate the amount of time a rock surface has been exposed.

lignicolous lichen:

A lichen that grows on stripped wood (lignin) – that is, on bare wood rather than bark.

ligulate: Also liguliform, lingulate, lorate. Narrow and flat, with the form of a strap.

lirella: Plural lirellae. Also hysterothecia, lirelline apothecia. A linear, which may be straight, curved, branched, or, with a longitudinal slit; characteristic of lichens in the genus Graphis. The term was first proposed by Michel Adanson in 1794.

lirellate: Also lirelliform. Having the form of.

litho-: A prefix meaning "stone" or "rock".

lithocortex: tissue made of closely compacted, agglutinated that forms a dense tissue layer.

lobate: Divided into, such as the of Lobaria scrobiculata.

lobe: A rounded or elongated projection of a edge; in technical descriptions, it is measured from its widest point.

lobule: A small lobe originating from the edge or surface of a lichen, typically the same color and character as the.

lobulate: Having small.

locule: Also loculus. A cavity or space.

lorate: See.

lumen: Plural lumina or lumens. An internal space or cavity in a structure, such as a cell,, or spore.

M
macrolichen: A lichen with a large enough that its main characteristics can be identified without the use of viewing magnification; generally refers to,, and species.

maculate: Covered with spots (maculae).

maniciform: Cuff-shaped; the term is used to describe that break open to form a central perforation revealing a duct to the cavity. Maniciform soralia occur in the genera Hypogymnia and Menegazzia.

marginal: On the margins. Contrast:.

marginate: Having a well-defined border or edge. Contrast:.

matte: Also: matt. A flat or non-reflective surface texture, lacking gloss or shine; contrast.

mazaedium: Plural mazaedia. A powdery mass of and formed by the disintegration of the  in the  of some lichens; associated with the order Caliciales. The term was first used by Erik Acharius in 1817.

medulla:

The internal tissue of a lichen, located beneath the and the layer, and usually made of loosely compacted.

medullary excipulum: See.

Melaena-red: A purple insoluble lichen pigment, associated with the reference species Micarea melaena.

Melaenida-red: A purple insoluble lichen pigment, associated with the reference species Micarea melaenida.

melanotopelioid: A morphotype of lichens describing a type of apothecium structure resembling  apothecia but characterized by a minimized. The distinctive feature of melanotopelioid apothecia is the presence of "teeth" that are black and, at least on the external surface.

melanotremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Melanotremoid lichens have prominent apothecia with wide pores and a black margin; pore filled with broad "stump" (columella); black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genera Melanotrema, Ocellularia, Clandestinotrema, and Trinathotrema.

micareiod: Referring to small green algal that often occur in pairs, as in the genus Micarea.

microcrystallization:

Also microcrystal test. A method used to identify some lichen products that involves re-crystallization on a microscope slide from a range of solvents and the formation of crystals with characteristic shapes; the crystals are examined microscopically for identification. Although this technique has largely been supplanted by the more reliable and sensitive technique of thin-layer chromatography, there are certain situations where it is still useful.

microlichen: A small lichen whose physical features cannot be distinguished without the aid of a 10X or greater viewing magnification; it generally refers to and species. The prefix "micro-" is also used to indicate small versions of particular growth forms, e.g. microfruticose or microfoliose.

microphylline: Having minute.

moniliform: Also monilioid. Having a form resembling a string of beads.

monophyllous: Referring to the of a that has only a single lobe.

multi-: A prefix meaning "more than one" or "many".

multiguttulate: Containing many oil droplets (guttules).

multilocular: See.

muriform: Divided into compartments or by intersecting longitudinal and transverse. The term was first used by Wilhelm Körber in 1855.

muscicolous lichen: See.

-mycetes: A suffix indicating the taxonomic rank of a fungal class.

mycobiont: The fungal part of a lichen, which combines with one or more s. The term was proposed by George Scott in 1957.

mycophycobiosis:

Also defined: mycophycobiont. A symbiosis where an ascomycete fungus is housed inside multicellular algae; the algae and fungus involved in this association are called mycophycobionts. Contrary to a lichen symbiosis, the fungal partner is the inhabitant, and the algal partner dominates.

myriotremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Myriotremoid lichens have immersed apothecia with small pores, and a smooth and more or less shiny thallus; this morphotype occurs in the glaucopallens group of genus Myriotrema.

N
necral layer: A layer of dead with indistinct found near or in the  of a. The term was first used by Alexander Elenkin in 1902. See related:,.

nitid: Shiny, glossy, or polished in appearance; contrast with.

nodulose: Having small, rounded elevations or nodules.

nubilated: Cloudy or obscured, often used to describe the appearance of lichen that are partially covered.

O
ob-: A prefix meaning "inversely" or "oppositely".

obclavate: Inversely, widest at the base.

obovate: Egg-shaped, with the narrower end at the base.

obpyriform: Shaped like an inverted pear. See related:.

ocellularioid: A morphotype of lichens used to describe characteristics of  and  morphology. Ocellularioid lichens have prominent apothecia with wide pores; pores with a "finger" (columella); black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genus Ocellularia.

-oid: A suffix meaning "like" or "having the form of". omphalodisc: An with a bump in the center that gives it the appearance of a navel; found in the genus Umbilicaria. The term was introduced by George Llano in 1950.

orcularioid: A brown, spore, characteristic of Rinodina section Orcularia.

ornithocoprophilic: Used to describe lichens that grow or proliferate in environments rich in bird excrement.

ostiole:

A small pore or opening; in lichens, it is used to refer to the -lined cavity in a that ends in a pore, or more generally to any pore from which spores are released from an -bearing fruit body.

ostropalean: Referring to asci that are with a thickened apex and a narrow canal ending in a pore; associated with species in the order Ostropales.

ovate: Egg-shaped, with the wider end at the base.

P
pachydermatous: Also pachyderm, pachydermate, pachydermous. Referring to that have an outer wall that is thicker than the internal cavity.

palisade cell: A terminal cell of a in a, aligned perpendicularly to the plane of the.

palisade plectenchyma: Plural palisade plectenchymata. Also palisadoplectenchyma, plural palisadoplectenchymata. A type of in a where the  are arranged perpendicularly to the plane of the.

pallidostegoboloid: A morphotype of lichens used to describe characteristics of  and  morphology. Pallidostegoboloid lichens have prominent apothecia with wide pores; pore filled with irregular structures; pale walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in wrightii group of the genus Stegobolus. papilla: Plural papillae. A small, conically rounded growth.

papillate: Also papillose. Covered with.

papilliform: Having the shape of a or nipple.

para-: Also par-. A prefix with several meanings, including "above", "beyond", "at the side", "against", "toward", and "almost".

paracephalodium: Plural paracephalodia. A mat of covering cyanobacteria, originating from a with a green algal. The term was introduced by Josef Poelt and Helmut Mayrhofer in 1988.

paraphysoid: A threadlike, sterile, l structure similar to a paraphysis, but typically branched and often forming a network.

paraplectenchyma: Plural paraplectenchymata. A type of comprising that are oriented in all directions; found in the  of many lichens.

parasoredium: A propagule, similar to a, that starts as a budlike structure with on an upper side and algae on a lower side, then develops into. Originally used to describe a structure found on the upper of Umbilicaria hirsuta.

parasymbiont: An organism that lives in close association with a host species, deriving benefits at the host's expense but not causing immediate harm; an intermediate state between symbiosis and parasitism.

parathecium: Plural parathecia. The outside layer of in an, curved upward along the margin of the ; the term is now obsolete, and equivalent to or. Otto Darbishire coined the term parathecium in an 1898 monograph on the genus Roccella.

parmelioid lichen: An informal growth form category used for lichens that are mostly, often closely attached to the substrate, and have and pycnidia; this group of features is characteristic of lichens previously classified in the genus Parmelia (in the broad sense).

PD test: Also P test. A that uses a 1–5% ethanolic solution of p-phenylenediamine as a reagent to check for the presence of certain lichen products.

pedicel: A small stalk used to support other structures, such as spores,, etc.

pedicellate: Having a.

peltate: Also clypeate, scutiform. Referring to a rounded structure attached on the lower side at a single central point (often on a short stalk), with free edges.

peltidiangium: A basket-like structure in which are produced.

peltidium: A reproductive propagule found in the lichen genus Gallaicolichen that is similar in form to a, but is unique in that the partner organizes the propagule and envelops (or nearly so) its. The term is derived from the name of the involved green algal genus, Phycopeltis.

pendant: Also pendent, pendulous. Hanging down, as in the of genus Usnea, the beard lichens. perforate: With splits or holes in the.

periclinal: Parallel to a surface; used to refer to hyphal alignment.

perifulcrum: The protective wall surrounding a.

periphysis: Plural periphyses. A short, sterile that develops from above the ascus and grows down a short distance, typically lining the internal walls of the ostiole in a.

periphysoid: -like structures that grow laterally; found in some crustose s.

perispore: Also defined: exospore, epispore, mesospore, endospore. The colorless and usually gelatinous outermost layer of a spore. This transparent layer determines the spore's shape. The other four layers of a spore, going inward, are the exospore, epispore, mesospore, and endospore.

perithecium: Plural perithecia. A spherical or flask-shaped that is sessile or partly immersed in the, with a single opening (ostiole) and enclosed by a distinct wall; a characteristic of. Although it was in 1831 that Elias Fries first applied the term perithecium to lichen fruit bodies, the word was originally coined by Christiaan Hendrik Persoon in 1794.

petricolous: See.

phaeolichen: A lichen in which the partner is brown algae (class Phaeophyceae); an example is lichen formed by the fungus Wahlenbergiella tavaresiae and the brown alga Petroderma maculiforme.

phenocortex: Plural phenocortices, phenocortexes. A structure, similar to a, containing fragments and dead, collapsed algal cells sloughed off from the.

photobiont: Also defined: phycobiont, cyanobiont. The photosynthetic component of a lichen. This can be either a green alga (known as a phycobiont) or a cyanobacteria (known as a cyanobiont). The term "phycobiont" was proposed by George Scott in 1957.

photobiont layer: See.

photomorph: An organism whose morphology is determined by the nature of its photosynthesis; applied to lichen-forming fungi whose have different forms with green algal versus cyanobacterial. The term was introduced by Jack Laundon in 1995 to address what he believed were deficiencies in related terms such as morph, morphotype, and.

photosymbiodeme: Morphologically different structures formed by the interaction of a single with two different. Examples occur in the genera Pseudocyphellaria and Sticta.

phycobiont: See:

phyllidium: Plural phyllidia. A small leaf-like or scale-like propagule that is and has distinct upper and lower sides (i.e., it is dorsiventral); it originates from the margins or on the upper surface of. Phyllidia occur in some species of the Lecanorales and the Peltigerales. phyllocladium: Plural phyllocladia. A -containing, outgrowth of ; common in the genus Stereocaulon. Their morphology can be characterised with various descriptors:,, , , , , and. The term was introduced by Theodor Fries in 1858.

phyllopsoroid: A lichen growth form characterized by mostly thalli with or  often overgrowing a thick ; this morphology occurs in the largely tropical genera Bacidiopsora, Eschatogonia, Phyllopsora, and Physcidia.

piriform: See.

placodioid lichen: Also placoid, placodiomorph. A with an center and radiating  on the circumference.

plasticolous lichen:

A lichen that grows on plastic.

platycarpoid: A morphotype of lichens used to describe characteristics of  and  structure. Similar to or, but the difference lies in the presence of a free  that forms a distinct double margin. It is exemplified in species such as Chapsa platycarpa and C. neei.

platygonidium: Plural platygonidia. that occur in star-shaped or circular colonies; now obsolete.

plectenchyma:

Plural plectenchymata. Fungal tissue made of twisted, intertwined ; used as a general term to refer to all types of fungal tissue. The term (and the use of the prefixes "para-" and "proso-" to modify it) was proposed by Gustav Lindau in 1899. See related:,, ,.

plicate: Characterised by longitudinal folds forming pleats, often used to describe closely adjacent, markedly convex thallus or elongated that display a "folded" appearance.

plurilocular: Also multilocular. Having many cavities or ; used to describe spore structure.

podetium:

Plural podetia. An upright, hollow, stem-like structure bearing and sometime conidiomata; typically associated with the Cladoniaceae, particularly the genus Cladonia. The term was first used by Erik Acharius in 1803.

POL test: A lichen test performed by shining a polarized light at a lichen structure in microscopic view; in the genus Hypogymnia, the presence (POL+) or absence (POL−) of POL-sensitive crystals in the is a useful to help distinguish species.

polarilocular: Also placodiomorphic, polar-diblastic, polaribilocular, polocellate. A spore divided into two components (locules) separated by a central septum with a perforation or. The term was first used by Wilhelm Körber in 1855 (as "polari-dyblastae") to describe the spores of Rhizocarpon and Umbilicaria. It was anglicized to "polari-bilocular" by William Mudd in 1861, and finally shortened to polarilocular by the Henri Olivier in 1882.

Polychroa-brown: An orange-brown to ochre insoluble lichen pigment, associated with the reference species Bacidia polychroa.

poriform: Shaped like or resembling a pore.

porinoid: A morphotype of lichens used to describe characteristics of  and  structure. This morphotype is similar to, but with a very narrow pore that resembles the opening of a true. Despite this, the hymenium remains organized in a distinct, compact layer with and  of similar height. Examples include Leucodecton bisporum, L. compunctellum, and T. patwardhanii.

praestantoid: A morphotype of lichens used to describe characteristics of  and  morphology. Praestantoid lichens have large and prominent apothecia with small pores; pores with "finger" (columella); black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the praestans group of the genus Ocellularia.

primary species: The sexually fertile member of a.

primary thallus: See.

prominent: Sticking out from the surface of the. A more precise definition has been suggested by Aptroot and Lücking, who propose that the term applies to and that are more than 1/2 above the level of the, and have a base that is expanded outwards.

proper margin: Also proper exciple, ectal excipulum, medullary excipulum, proprium. A ring of tissue around the of a ; this tissue, which originates from the, is not lichenized, and is internal to the  (if present). The term "proper margin" was first used by Erik Acharius in 1803; in 1825 Elias Fries changed the noun and called it "proper exciple".

proprium:

See. prosenchyma: Plural prosenchymata. A type of in which the constituent fungal are arranged parallel to each other, such that individual hyphae can be clearly distinguished using microscopy.

prosoplectenchyma: Plural prosoplectenchymata. A type of, common in the of lichens, in which the constituent fungal  are aligned in a particular direction. prothallus:

A fungal layer upon which an algae-containing may develop, lacking ; usually white, brown, or black, and found between the s and at the growing margins of s. The term was first used by Georg Meyer in 1825.

prototunicate: A form of in which the wall breaks down before maturity (thus releasing its ), and which lacks differentiated apical structures.

proximal: Positioned close to a point of origin or near the center of a body.

pruina: A powdery, frost-like or flour-like deposit on a surface. In lichens, pruina is often the result of the accumulation of crystalline hydrates of calcium oxalate, of lichen products, or sometimes of the dead or dying cells of the.

Pruinose: Also pruinate. Covered with.

pseudo-: Also pseud-. A prefix meaning "false"; used in terminology to denote something is false, or that one structure resembles something else, such as the resembling the.

pseudoamyloid: See.

pseudocortex: Plural pseudocortices, pseudocortexes. A boundary layer of the containing distinct that are not organized into a regular tissue structure; sometimes used to refer to the false  present on the outer layer of, such as those found in the lichen Pycnothelia papillaria. pseudocyphella:

Plural pseudocyphellae. Small openings in the of a lichen, where the is exposed to air, and there are no specialized cells surrounding the cavity. The term was first used by William Nylander in 1858.

pseudoisidium: Plural pseudoisidia. An outgrowth on the surface of a lichen that somewhat resembles an, but lacks photosynthetic cells; pseudoisidia are common in the genus Pseudocyphellaria.

pseudoparaphysis: Also cataphysis. A -like that forms in the locule or perithecial cavity before the formation of the ascus; it grows downward from the top of the cavity to the base of the ascomata.

pseudoparenchyma: Plural pseudoparenchymata. A type of made of tightly packed, angular or polyhedral cells.

pseudopodetium: Plural pseudopodetia. Solid, upright stalks originating from the. They are similar to, but are made of (rather than generative) tissue. They are associated with the genera Baeomyces, Dibaeis, Leprocaulon, Pilophorus, and Stereocaulon. The term was introduced by Gustav Krabbe in 1882.

pseudostroma: Plural pseudostromata. A made of both tissue and bits of host tissue. The term was used first for lichenized fungi Edvard August Vainio in 1890.

pubescent: Covered with short, soft, fine hairs or down.

pulverulent: Characterised by a fine, powdery surface or consistency; resembling or appearing as dust or powder.

punctate: Having a pattern of minute spots or tiny holes (also known as puncta).

punctiform: Very small or tiny, appearing as a point or dot.

pustulate: Also pustulose. Covered with.

pustule: A blister- or wart-like structure, usually hollow.

pycnidium: Plural pycnidia. An asexual fruiting body, or, that is typically round,, or. It has a circular or elongated that has an inner surface lined with. Pycnidia are common in anamorphic fungi, including many lichenicolous species.

pycnoascocarp: A type of that originates from a ; characteristic of the family Lichinaceae. The term was first used by Aino Henssen in 1963.

pyrenolichen: A lichen that produces.

pyriform: Also piriform. Shaped like a pear. See related:.

R
radial: Also radiate. Referring to lichen, symmetrical around a central axis in transverse section, such as in the genera Alectoria, Bryoria, and Usnea.

radiate: Spreading from a central point.

recurved: Also recurvate, reflexed. Curved or bent back; in lichens, these terms are used to describe the tips of or that are curved up or down, or back onto themselves.

redingerioid: A morphotype of lichens used to describe characteristics of  and  morphology. Redingerioid lichens have immersed apothecia with linear slit; slit filled with irregular structures; black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genera Redingeria and Stegobolus.

reimnitzioid: A morphotype of lichens used to describe characteristics of  and  morphology. Reimnitzioid lichens have open apothecia with erect, and a rough thallus containing crystals; this morphotype occurs in the genus Reimnitzia.

reniform: Shaped like a kidney.

reticulate: Marked like a net or network. rhizine:

Also rhizina, plural rhizinae. A root-like structure that serves as an attachment structure in many foliose lichens.

rhizinomorph: A root-like structure similar to a that is not involved as an attachment organ; associated with.

Rhizinose strand: An attachment organ, similar to a, comprising tough and irregularly branched ; found in some, such as in the genera Catolechia and Toninia.

Rhizohypha: A single strand on the underside that serves as an attachment organ.

rhodostromoid: A morphotype of lichens used to describe characteristics of  and  morphology. Rhodostromoid lichens have large and prominent apothecia with small pores; pore with “finger” (columella); black walls and pigment (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the rhodostroma group of the genus Ocellularia.

Rimose: Also rimous. Having cracks or splits.

Rimula: Plural rimulae. Small, rim-like structures or cracks.

Rimulose: Also rimulous. Having minute cracks or splits.

Rivose: Marked with curvy and irregular furrows, like the of some s.

Rivulose: Marked with thin, winding or crooked lines.

Rostrate: Having a.

Rostrum: Plural rostra. A beak-like projection.

Ruginosa-brown: A dark red to almost black insoluble lichen pigment, associated with the reference species Toninia ruginosa.

Rugose: Also rugous. Having a rough texture; wrinkled and creased.

Rugulose: Also rugulate. Having a slightly rough texture; with slight wrinkles and creases.

Rupicolous: See.

S
saccate: Sac- or bag-like in form.

saxicolous lichen:

A lichen that grows on stone.

scabioid: A morphotype of lichens used to describe characteristics of  and  structure. This morphotype resembles the but features recurring hymenia that produce layered, which eventually cover the ; examples include Chapsa aggregata and C. albomaculata.

scabrous: Also scabrose, scabrid, scabridous. With a crusty, rough surface often resulting from the accumulation of dead cortical material.

schizidium: Plural schizidia. A scale-like propagule originating from the upper layers of a lichen. The term was proposed by Josef Poelt in 1965.

schizobiont: A bacterium that lives in or is associated with a lichen.

schizotremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Schizotremoid lichens lack apothecia and have, and a smooth, more or less shiny thallus; this morphotype occurs in the genus Stegobolus.

Schweinitzii-red: A dark red insoluble lichen pigment, associated with the reference species Bacidia schweinitzii.

scleroplectenchyma: Plural scleroplectenchymata. A type of comprising thick-walled that are stuck closely together; present as a component of the  tissue supporting the  in the genera Cladonia and Alectoria.

scrobiculate: Having large, shallow depressions that are narrowly separated by rounded ridges. Compare:,.

scyphus: Plural scyphi. The cup-shaped part at the tip of a lichenized, common in the genus Cladonia. The term was first used by Johann Dillenius in 1742, and later adopted by Carl Linnaeus in 1753.

scutiform: See.

secondary species: The sexually infertile member of a that only reproduces.

secondary thallus: See.

Sedifolia-gray: A blackish-gray to gray-green insoluble lichen pigment, associated with the reference species Toninia sedifolia.

segment: A section of a that is demarcated by an annular (ring-like) crack.

septum:

A wall or partition in a, cell, or spore.

seriate: Arranged in rows.

sessile:

Lacking a stem. A more precise definition has been suggested by Aptroot and Lücking, who propose that the term applies to and that are more than 3/4 above the level of the, with a constricted base.

sibling species: Closely related species that are morphologically indistinguishable but can be distinguished by non-morphological traits, such as chemistry or genetic differences. Initially defined as species recognized mainly through cryptic or non-morphological discontinuities, the concept has evolved to specifically refer to cryptic species that form a monophyletic group, meaning they share a common ancestor not shared with any other species. This concept is a subset of the broader terms and "cryptic species".

sigmoid: Curved upon itself twice, like the letter "S".

simple: Lacking branches or divisions; in lichenology, it is used to describe structures such as or, or without.

siphuloid: An informal growth form category applied to lichen genera with a superficially similar to morphology, notably Siphula, Siphulella, Siphulopsis, Parasiphula, and Knightiellastrum.

soleiform: Shaped like the sole of a shoe, with a flat, elongated, and slightly curved appearance.

soralium: Plural soralia. A part of the where the has cracked or broken down and  are produced. Soralia can be further characterized as diffuse if they are spread out on the upper thallus surface as a continuous layer, or delimited if they are confined to a more restricted area. If soralia originate in tubercules they are tuberculate, while they are fissural if they are created in fissures. The term was proposed by Johannes Reinke in 1895.

sorediate: Having.

sorediotremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Sorediotremoid lichens lack apothecia and have, and a smooth, more or less shiny thallus; this morphotype occurs in the genera Myriotrema and Ocellularia.

soredium: Plural soredia. A powdery to granular reproductive propagule that is not covered with a well-defined (in contrast to, and contains both algal and fungal  components. The term was first used by Erik Acharius in 1803.

spathulate: Spoon-shaped.

species pair: Two lichen species that are identical morphologically, anatomically, and chemically, but can be distinguished by their sexual versus asexual reproductive strategies; the fertile taxon is known as the primary species, while the taxon is known as the secondary species. The use of molecular methods to analyze putative species pairs has shown that the underlying phylogenetic situation is more complex than had been assumed, and not necessarily correlated with reproductive strategy. See related:.

spermogonium: Also spermagone, spermagonium. In lichenology, an obsolete term for.

sphaeridium: Plural sphaeridia; see.

spinule: A small spine; in some lichens of the Lecanoromycetes, it refers to a small cylindrical outgrowth, with a narrow base, in which the is not connected with the  of the main branch.

spinulose: Also spinulous. Covered with or having small spines or spiny projections. spongiostratum: Plural spongiostrata. A spongy found on the lower surface of the genera Anzia and Pannoparmelia.

sporodochium: Plural sporodochia. A cushion-shaped consisting of short and  that supports a spore mass.

sporomorph: A lichen species that is extremely similar (or identical) in external morphology, anatomy, chemistry, and spore size to another, but that is placed in a different genus solely based on differences in spore septation and/or spore colour. The term was introduced by Michael Wirth and Mason Hale in their 1978 monograph about the Graphidaceae, a family in which sporomorphs are common. spot test:

A spot analysis used to help identify lichens; it is performed by placing a drop of a reagent on different parts of the lichen and noting any color change associated with application of the reagent. The four most common tests are,, , and.

squamulose lichen:

A lichen with a made of numerous small scales or ; intermediate in form between and  lichens.

squarrose: Brush-like, with many short, more or less perpendicular lateral branches. In lichenology, used to refer to structure.

stegoboloid: A morphotype of lichens used to describe characteristics of  and  morphology. Stegoboloid lichens have prominent apothecia with wide pores; pore filled with irregular structures; black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genus Stegobolus.

stereoma: Plural stereomata. Tissue that provides support for the in some species of Lecanorales. See related:.

stratified thallus: A that is divided into distinct layers (strata). See related:.

stroma:

Plural stromata. A dense mass of that supports spore-bearing structures. In lichens, the stroma is often hard and carbonaceous.

sub-: A prefix meaning "below", "under", "somewhat, or "almost". Also used in front of names of taxonomic ranks to indicate intermediate categories, e.g. subspecies or subgenus.

subhymenium: The tissue immediately below the. The term was first used by Gustaf Einar Du Rietz in 1945.

subiculum: Also subicule. Plural subicula. A layer of loosely-compacted mycelia that covers the and cushions fruiting bodies such as and. The texture of the subiculum can be described as net-like, wool-like, or crust-like.

substrate:

Also substratum; plural substrata. The surface or base upon which a lichen grows or is attached. Although the terms substratum and substrate are often used equivalently in lichenology, the latter term has different meanings in microbiology and in enzymology.

subulate: Slender and narrowing to a fine point; awl-shaped.

sulcate: With grooves or furrows.

Superba-brown: An orange-brown to ochre insoluble lichen pigment, associated with the reference species Porpidia superba.

superficial: On the surface.

T
tartareous: Also tartarean. Having a thick, rough, and crumbly surface.

taxon:

Plural taxa. A taxonomic group of any rank; this includes species, genera, families, etc., up to kingdom and even higher.

tenuitremoid: A morphotype of lichens used to describe characteristics of  and  morphology. Tenuitremoid lichens have immersed apothecia with small pores and a black margin; pore with “finger” (columella); black walls (viewed in microscopic section); and a smooth, more or less shiny thallus. This morphotype occurs in the genus Clandestinotrema.

tegulicolous lichen: A lichen that lives on tiles. In general, these are or lichens that are indifferent as to their substrate.

terebrate: A with widely spaced perforations.

terete: Describing a cylindrical or rod-like structure that is round in cross-section.

teretiform: Describing a shape that is nearly cylindrical or rod-like, similar to but not exactly ; circular in cross-section, gradually tapering towards one end.

terricolous lichen:

A lichen that grows on soil.

tessellate:

As if formed of small squares or mosaics, like the of Rhizocarpon geographicum.

thalline margin: Also thalline exciple, excipulum thallinum. A rim of tissue around the of a ; this tissue, external to the inner, is made of tissue with a structure similar to that of the. The term "thalline margin" was first used by Erik Acharius in 1803; in 1825 Elias Fries changed the noun and called it "thalline exciple".

thallinocarp: A type of characteristic of the genus Lichinella (family Lichinaceae); they form from indistinct swellings of the, with a hymenium covered by groups of algal cells.

thalloconidium: Plural thalloconidia. A dark brown, smooth to wrinkled propagule arising directly from a, particularly the lower and/or the. They are found in some species of Umbilicaria, and similar structures arise from the of some species in the genera Protoparmelia, Rhizoplaca, and Sporastatia. Thalloconidia have distinct cell layers in their walls, and comprise between 1 and about 2500 cells.

thalloid: Similar to a.

thallospore: An asexual spore produced directly in the or in mycelium. In lichens, they are primarily associated with the genus Umbilicaria, although they also occur in some.

thallus:

Plural thalli. The body of a lichen, made up of both fungal and algal or cyanobacterial cells. The term was first used by Erik Acharius in 1803.

thallyle: A small thallus that originates from ; typically associated with the genus Umbilicaria.

thecium: Plural thecia. The part of an that contains the and is situated between the  and the. The term is alternatively used more generally to refer to any fruit body that is delimited by a proper wall (i.e., containing only fungal cells), or, as equivalent to. This last usage was first employed by William Nylander in 1853. See related:,, , ,.



thelotremoid: A morphological group of lichens within the Graphidaceae, the largest family of. Thelotremoid lichens are characterized by immersed-, rounded, non-branched to slightly branched, mostly ascospores, and mostly a. Thelotremataceae, a traditional family of lichens, has been included in Graphidaceae, and its species are now informally accepted as thelotremoid lichens.

tholus: Plural tholi. Also dome. The apical, often thickened part of the inner wall in a.

tomentum: Plural tomenta. Also defined: tomentose. A layer of short interwoven or coiled fungal with a texture similar to velvet. In lichens, the tomentum projects from the lower and serves to help it attach to its. Structures with this type of hyphae are called tomentose. Tomentose surfaces are found in genera such as Lobaria, Pseudocyphellaria, and Sticta.

topeliopsidoid: A morphotype of lichens used to describe characteristics of  and  structure. It pertains to lichens where the apothecia are either prominent or, often hidden between the, and they open with multiple, typically regular "teeth" that stay relatively curved over the hardly visible. The margins tend to peel off, meaning the overlaying thallus cortex separates from the underlying marginal thallus tissue, but no distinct, clean split between thallus margin and is formed. This morphotype is seen in species like Chapsa meridensis and Topeliopsis.

trabecula: Plural trabeculae. In the genus Umbilicaria, they are rib- or strap-shaped structures radiating outward from the that merge towards the mid-zone of the undersurface.

trentepohlioid: Resembling or belonging to the green algal genus Trentepohlia; trentepohlioid cells are filamentous (elongated and cylindrical), multicellular, and have a yellow to orange colour.

trebouxioid: Resembling or belonging to the green algal genus Trebouxia; trebouxioid cells are with a single central chloroplast.

triguttulate: Containing three oil droplets (guttules).

tripartite lichen: A lichen with a three-partner symbiotic association of,, and. See related:.

tuberculate: Also tubercular. Covered with.

tubercule: Also tubercle. A small rounded wart-like projection on a surface.

U
umbilicate lichen: Also defined: funiculus, umbilicus, umbilical cord. A lichen with a concave, circular, leafy that is joined to its only by its central part, called an umbilicus, umbilical cord or funiculus.

unciform: Hook-shaped.

undulate: Having a wavy form, margin, or surface.

uni-: A prefix meaning "one"; equivalent to the prefix "mono-".

uniguttulate: Containing a single oil droplet (guttule).

unilocular: Containing a single cavity or.

uniseriate: Lined up in a single row.

unitunicate: A type of with a single functional layer; the rigid internal and external wall layers do not separate during release of the. Most ascomycetes have unitunicate asci.

urceolarioid: A morphotype of lichens used to describe characteristics of  and  structure. In this, the fruiting bodies are noticeable to and have a narrow pore with a smooth margin, through which the  and  are not visible. This morphotype can be observed in Thelotrema isidiophorum, T. subweberi, and T. weberi.

urceolate: Deeply cup-shaped or urn-shaped; in lichens, the term is used to describe some with a sunken and elevated  that forms a narrow mouth.

usneoid lichen: An informal growth form category used for lichens with an elastic in the ; these features are characteristic of lichens in the genera Dolichousnea and Usnea.

UV test: A lichen test performed by shining a long-wavelength ultraviolet light (350 nm) at a lichen structure to check if it fluoresces; a positive test (abbreviated as UV+) indicates the presence of certain lichen products. Xanthone compounds in the tend to fluoresce yellow, orange, or red, while depsides and depsidones in the fluoresce blue to white.

V
vagrant:

A lichen not attached to a, typically able to be blown around by wind.

vegetative: Also assimilative. Having to do with the growth phase of an organism before reproduction, including spore germination, growth, development and asexual multiplication.

vegetative reproduction:

Also vegetative multiplication. Any form of asexual reproduction; in lichens, this can involve just the (as with ), or both the and, as with, , and.

vein: A cord of tissue on the underside of a, common in the genus Peltigera.

verruca: Plural verrucae. A small, cone-shaped protuberance, like a small wart.

Verrucarioides-brown: A dull brown insoluble lichen pigment, associated with the reference species Toninia verrucarioides.

verruciform: Having a wart-like shape.

verrucose: A rough surface covered with.

verruculose: A surface covered with tiny ; delicately.

vitricolous lichen: A lichen that grows on glass.

voucher: A museum specimen that corresponds to a field collection.

X
xantho-: Also xanth-. A prefix used to indicate the color yellow. xantholichen: A lichen in which the partner is yellow-green algae (class Xanthophyceae); an example is the lichen formed by the fungus Verrucaria funckii and the yellow-green alga Heterococcus caespitosus.

Z
zeorine: An with both a and a. The term refers to apothecia characteristic of Zeora, a defunct genus that is now synonymous with Lecanora; consequently, the term is more or less obsolete and is equivalent to.

zonate: Having concentric lines that form alternating light and dark zones near the margin of a.