- Aggregate thallus
- of leprose lichens whose granules are scattered or clumped but not arranged in a single even layer resembling a foliose lichen
- Amphithecium
- all the tissues in the rim of a lecanorine apothecium, generally a cortex, algal layer and medulla
- Anamorphic fungi
- artificial grouping of asexually reproducing fungi (via conidia) including both Basidiomycetes and Ascomycetes
- Apothecium, pl. apothecia
- a disk or cup-like fungal reproductive structure where the hymenium is directly exposed to the environment
- Areolate
- a thallus composed of areoles, or lichen surface appearing composed of areoles
- Areole
- small, tile-like patch of thallus, discrete from others or crowded
- Ascoma, pl. ascomata
- spore-producing structure of an ascomycete fungus, e.g., apothecium, perithecium, or other, containing asci
- Ascomycete
- any fungus in the phylum Ascomycota, with spores produced in asci; most lichens are ascomycetes
- Ascus, pl. asci
- the sac in which spores are produced in ascomycete fungi
- Basidiomycete
- any fungus in the phylum Basidiomycota, in which spores are produced on specialized club-like cells called basidia; only a few lichens or lichen-like compound organisms are basidiomycetes
- Blastidium, pl. blastidia
- a granular asexual reproductive structure produced in a budding process from the margin of a lichen thallus
- Byssoid
- referring to all or part of a lichen thallus composed of a mat of fungal hyphae, or made up of a mat of filamentous algae associated with fungal hyphae
- C or Cl
- chlorine bleach, used in spot tests to detect secondary metabolites (e.g., gyrophoric acid, olivetoric acid)
- Capitulum
- a cup-shaped or hemispherical apothecium formed at the tip of a stalk in some lichens
- Carbonized
- referring to tissue that is black, opaque and brittle, e.g., the exciple in some apothecia
- Cephalodium, pl. cephalodia
- a gall-like structure on the surface or within certain green-algal lichens, containing cyanobacteria, used as a source of nitrogen by some lichens
- Chemistry
- used in lichenology to refer to secondary metabolites that are created by some lichens for various purposes, & differences among which are used to distinguish species; detected via color, spot tests, UV tests, or thin-layer chromatography
- Conidium, pl. conidia
- asexual spores produced within specialized structures, e.g., pycnidia, hyphophores
- Cortex
- the hardened, protective outer layers of a lichen thallus or apothecium, made up of gelatinized fungal hyphae or occasionally cells of a basidiomycete yeast
- Corticate
- composed of or including a cortex
- Corticolous
- of lichens that favor bark as a substrate
- Crenulate
- having a wavy or fluted edge
- Crustose
- any lichen entirely adhering to or slightly within its substrate and without a lower cortex
- Cyanobacterium, pl. cyanobacteria
- bacteria capable of photosynthesis, sometimes used as photobionts in a lichen symbiosis, or occasionally as a source of nitrogenous nutrients (since they can fix atmospheric nitrogen) when contained in cephalodia
- Cyphella, pl. cyphellae
- a specialized opening in the lower cortex exposing tissues within, characteristic of lichens in genus Sticta
- Diahypha, pl. diahyphae
- specialized conidia, often filaments of multiple cells, produced on or within hyphophores, especially in Gyalideopsis and other members of family Gomphillaceae
- Diaspore
- any asexual reproductive fragment of a lichen, e.g., soredia, isidia, schizidia, lobule, etc.
- Endospore
- intercellular substance between cells or lumina in some spores (e.g., Pyrenula)
- Esorediate
- entirely without soredia
- Exciple
- a layer of tissue in the apothecium surrounding the hymenium and hypothecium
- Foliose
- any lichen with a leafy structure, often with a definite upper and lower surface and stratified interior
- Fruticose
- any lichen with a shrubby structure, lacking a definite upper or lower surface, and usually with algae beneath every surface
- Goniocyst
- packet of algal cells surrounded by a fungal layer
- Halonate
- with a gelatinous halo surrounding each spore
- Hepaticolous
- growing on liverworts
- Hyaline
- of spores or sections of apothecia, when they are clear, colorless or free of pigment
- Hymenium
- the spore-producing layer within an ascoma, with asci and specialized fungal filaments (e.g., paraphyses)
- Hypha, pl. hyphae
- cell of a fungus, usually filamentous (sometimes spherical or cuboidal)
- Hyphomycetes
- a group of fungi often referred to as Fungi imperfecti, Deuteromycota, or anamorphic fungi; hyphomycetes lack closed fruit bodies, & are often referred to as molds
- Hyphophore
- a fertile stalked structure produced by some lichen crusts in Gomphillaceae, often expanded into a blade, fan or umbrella-shape near the top, bearing a bundle of thread-shaped diahyphae
- Hypothecium
- layer of fungal tissue beneath the hymenium, sometimes pigmented, often merging with and difficult to distinguish from the exciple
- Inspersed
- containing fine granules or oil droplets, e.g., in the hymenium, resulting in a granular cloudiness in the tissue
- Isidiate
- of a lichen thallus that produces isidia
- Isidium, pl. isidia
- a specialized asexual reproductive structure projecting from the surface or margin of a lichen, fingerlike (branched or not) or small and knobby
- K or KOH
- potassium hydroxide, used in spot tests to detect secondary metabolites (e.g., atranorin, norstictic acid)
- KC
- spot test combination, testing first with K and then with C, used to test for secondary metabolites (e.g., usnic acid, protocetraric acid)
- Labium, pl. labia
- the lip-like sides of lirellae in some script crusts
- Laminal
- on the upper surface of a lichen thallus
- Lateral
- on the sides of a lichen thallus, e.g., along the sides of a foliose lichen’s lobes
- Lecanorine
- describing the rims of apothecia, in which the rim functions as an extension of the thallus, with a cortex, algal layer and medulla, and is the same color as the thallus
- Leprose
- lichen thallus composed entirely of granules, each made up of algal cells surrounded by a sphere of fungal hyphae
- Lichenicolous
- fungi that live in or on the thalli of lichens, either as parasites or in some other type of symbiosis
- Lichenized
- a fungus adapted to life as a lichen, using a photobiont as a food source
- Lignicolous
- of a lichen preferring decorticate wood as a substrate
- Lirella, pl. lirellae
- specialized apothecia growing in two directions (rather than radially), creating a linear, often branched structure
- Lirelliform
- of a structure in the form of or resembling a lirella
- Lobarion
- community of corticolous lichens including various species of Lobaria, Ricasolia, Crocodia & cyanolichens, especially those in Sticta and family Pannariaceae; thought to be pollution-intolerant, & indicative of undisturbed or old-growth forests
- Lumen, pl. lumina
- the membrane-defined space(s) within a spore containing germ cell(s), either entirely filling the spore to cell walls, or with an intercellular substance called endospore between lumina & cell walls
- Mazaedium, pl. mazaedia
- a dry, powdery mass of spores and disintegrating tissues of the apothecia of some lichens (especially in Caliciales)
- Medulla
- inner fungal layers beneath the algal layer of many lichens, chemically distinct from the cortex
- Muscicolous
- of lichens preferring to grow on bryophytes
- Mycobiont
- the fungal partner in the lichen symbiosis
- Ostiole
- the pore of a lichen ascoma or pycnidium through which spores emerge
- P or PD
- para-phenylenediamine, a chemical used in spot tests to detect secondary metabolites (e.g., fumarprotocetraric acid, pannarin)
- Perithecium, pl. perithecia
- ascoma in which the hymenium is entirely enclosed within the exciple, opening to the environment through the ostiole
- Photobiont
- the photosynthetic organism supplying food and/or other nutrients to the lichen, either an alga or cyanobacterium (if more than one, distinguished as primary or secondary photobionts)
- Placodioid thallus
- of leprose lichens whose granules are densely arranged in an even layer resembling a foliose lichen
- Prothallus
- the growing edge of the lichen, containing the primary fungus without photobiont, usually differently colored than the thallus
- Pruina
- a dusting or layer of powder or crystals on the surface of a lichen
- Pseudocyphella, pl. pseudocyphellae
- pit-like pore on the surface of a lichen exposing the medulla
- Pseudostroma, pl. pseudostromata
- a specialized layer of fungal tissue, often raised above the thallus, in which ascomata are imbedded
- Pyrenolichen
- any lichen in which the reproductive structures are perithecia
- Revolute
- referring to lobe morphology, with margins curling under, not remaining plane or flat
- Rhizine
- specialized fungal structures attaching some foliose lichens to the substrate
- Rhizohypha, pl. rhizohyphae
- hyphae that perform the same function as rhizines
- Rimose
- of a lichen thallus that is cracked into polygons, sometimes difficult to discern from a crowded areolate thallus
- Saprophytic
- of fungi that obtain nutrients from the breakdown of dead plant tissue
- Saxicolous
- of lichens that prefer to grow on rock
- Septate
- divided by layers or divisions, especially spores divided into multiple cells along their length
- Sessile
- resting on the surface, as apothecia that lie flat on the thallus (rather than immersed in it)
- Seta, pl. setae
- a sterile, rigid, acute-tipped bristle on a crustose lichen
- Sorediate
- of a lichen that reproduces via soredia
- Soredium, pl. soredia
- a specialized asexual reproductive granule made up of algal cells surrounded by a layer of fungal hyphae
- Spore
- the reproductive entity of a fungus, either produced sexually within an ascus (sometimes referred to as ascospores) or asexually (conidia)
- Spot test
- applying a minute amount of a chemical (e.g., KOH, Cl, PD) or sequence of chemicals on a specific lichen tissue to note color changes; used in lichen identification
- Squamule
- a scale-like projection of a lichen thallus, determinate in size, either in a thallus partly or entirely composed of squamules (e.g., many Cladonia) or as scaly asexual reproductive structures on some foliose lichens
- Squamulose
- with squamules; of a lichen whose thallus is composed partly or entirely of squamules, spreading by the creation of more at thallus edges
- Stipitate
- on a stalk or other distinct stem-like structure
- Striate
- used to describe labia in Graphis, when they are composed of layers of carbonized material, usually visible under a dissecting scope as grooves along the length of tops of labia, but most apparent when wet mounts of cross sections are examined under higher magnification
- Synnema, pl. synnemata
- a large, erect reproductive structure in some fungi, bearing compact conidiophores that fuse together to form a strand with conidia at the end or on the edges
- Terminal
- referring to something at the tip of a lobe or other lichen structure (e.g., a podetium)
- Terricolous
- typically growing on or over soil
- Thallus, pl. thalli
- the body of a lichen, presumed to contain all the elements that make up the compound organism, including primary fungus, one or more photobionts, & associated microbiome
- Turbinate
- in the shape of a turban: puffed out at sides beyond the edges of base
- UV
- Ultraviolet light, used to test for secondary metabolites (e.g., lichexanthone, divaricatic acid)
- Verrucose
- of a thallus surface, with slightly to abundantly bumpy
- Verruculose
- minutely bumpy surface (i.e., smaller bumps than in verrucose)
