''Aspicilia'' (sunken disk lichen) is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of mostly

crustose Crustose is a Habit (biology), habit of some types of algae and lichens in which the organism grows tightly appressed to a substrate, forming a biological layer. ''Crustose'' adheres very closely to the Substrate (biology), substrates at all poin ...

areolate Lichens are symbiotic organisms made up of multiple species: a fungus, one or more photobionts (an alga and/or a cyanobacteria) and sometimes a yeast. They are regularly grouped by their external appearance – a characteristic known as their gro ...

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

s that grow on rock. Most members have black

apothecia An ascocarp, or ascoma (: ascomata), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. As ...

discs that are slightly immersed in the areolas, hence the

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

"''Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, ''Given the same reason, the naming of ''Aspicilia'' is derived from the Greek word for "shield concave". Most of the species of this genus grow on

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime (mineral), lime or being chalky. The term is used in a wide variety of Science, scientific disciplines. In zoology ''Calcare ...

and acidic rocks and most of the taxa prefer

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

and arctic habitats. Some members of the genus ''Aspicilia'' are

pioneer species Pioneer species are resilient species that are the first to colonize barren environments, or to repopulate disrupted biodiverse steady-state ecosystems as part of ecological succession. Various kinds of events can create good conditions for pi ...

on granite and other hard rock, after which members of other lichen species may grow on them, such as members of ''

Acarospora ''Acarospora'' is a genus of mostly lichen-forming fungi in the family Acarosporaceae. Most species in the genus are crustose lichens that grow on rocks in open and arid places all over the world. They may look like a cobblestone road or cracke ...

''.ACAROPSPORA, Lichen Flora of the Greater Sonoran Desert Region. Vol 3., Nash, T.H., Ryan, B.D., Gries, C., Bugartz, F., (eds.) 2001

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Description

Members of this genus are weakly cracked to distinctly areolate, with a scattered to whole thallus, thalli. Some of the species of this genus are disc-shaped with plicate lobes at the circumference; these lobes may appear chalky white, grayish, greenish or brownish. Some possess vegetative means of propagation such as

isidia An isidium (plural: isidia) is a tiny, wart- or finger-like outgrowth on the thallus surface of certain lichen species. It is one of two principal types of vegetative reproduction, vegetative reproductive structures in lichens, the other being ...

(column-like structures of fungal and algal cells normally found on the top-side or outer cortex of the lichen) and

soredia Soredia are common reproduction, reproductive structures of lichens. Lichens asexual reproduction, reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungus, fung ...

(structures that produce soralia, granule-like masses of intertwined fungal and algal cells occurring on top of the cortex and on the margins). They have characteristic

ascomata An ascocarp, or ascoma (: ascomata), is the fruiting body (sporocarp (fungi), sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded ascus, asci, each of which typically contains four to ...

which are mostly immersed but occasionally emergent. They have 4 to 8 spored asci that are cylindrical to club-shaped. Their

ascospores In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse division of fungi. After two parental nuclei fuse, the ascus undergoes meiosis (halving of ...

are typically

ellipsoid An ellipsoid is a surface that can be obtained from a sphere by deforming it by means of directional Scaling (geometry), scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a Surface (mathemat ...

globose This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary ...

in shape, colorless and thin-walled. They often contain β-orcinol depsidones (

secondary metabolite Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved ...

s of lichens) such as

norstictic acid Norstictic acid is a depsidone produced as a secondary metabolites in lichens. The compound contains both an aldehyde carbonyl group and an adjacent hydroxyl In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical fo ...

and

stictic acid Stictic acid is an aromatic organic compound, a product of secondary metabolism in some species of lichens. Stictic acid is the subject of preliminary biomedical research. Stictic acid has cytotoxic and apoptotic effects ''in vitro ''In v ...

s; others have

fatty acids In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...

triterpenes Triterpenes are a class of terpenes composed of six isoprene units with the molecular formula C30H48; they may also be thought of as consisting of three terpene units. Animals, plants and fungi all produce triterpenes, including squalene, the pre ...

. In genus ''Aspicilia'' dramatic changes in growth forms are very common, and some taxa may display extreme transitions within the same population or even changes within the same thallus.

Classification

Previously placed in the family

Hymeneliaceae Hymeneliaceae is a family of lichen-forming fungi in the order Baeomycetales. It contains three genera and about 40 species. The family was circumscribed by German lichenologist Gustav Wilhelm Körber in 1855. Lichens in the Hymeneliaceae ar ...

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analyses indicate that the genus is better placed in the family

Megasporaceae Megasporaceae are a family of fungi belonging to the order Pertusariales. Taxa are lichenized with green algae, and grow on rocks, often in maritime climates close to fresh water. Phylogenetic In biology, phylogenetics () is the study of the ...

Species

Species Fungorum ''Index Fungorum'' is an international project to index all formal names (Binomial nomenclature, scientific names) in the fungus Kingdom (biology), kingdom. As of 2015, the project is based at the Royal Botanic Gardens, Kew, one of three partn ...

accepts 70 species of ''Aspicilia''. *''

Aspicilia abbasiana ''Aspicilia'' (sunken disk lichen) is a genus of mostly crustose lichen, crustose areolate lichen, areolate lichens that grow on rock. Most members have black apothecia discs that are slightly immersed in the areolas, hence the List of common na ...

'' *'' Aspicilia albosparsa'' *'' Aspicilia angelica'' *'' Aspicilia aquatica'' *'' Aspicilia arizonica'' *''

Aspicilia armeniaca ''Aspicilia'' (sunken disk lichen) is a genus of mostly crustose lichen, crustose areolate lichen, areolate lichens that grow on rock. Most members have black apothecia discs that are slightly immersed in the areolas, hence the List of common na ...

'' *'' Aspicilia aurantiaca'' *'' Aspicilia auricularis'' *'' Aspicilia berntii'' *'' Aspicilia bicensis'' *'' Aspicilia blastidiata'' *'' Aspicilia boykinii'' *'' Aspicilia brucei'' *'' Aspicilia calcitrapa'' *'' Aspicilia californica'' *'' Aspicilia candida'' *''

Aspicilia cinerea ''Aspicilia cinerea'' (cinder lichen) is a gray to almost white, wide, crustose lichen, crustose areolate lichen with large apothecia that mostly grows on rock in the mountains.Lichen Flora of the Greater Sonoran Desert Region. Vol 3., Nash, T.H ...

'' *'' Aspicilia confusa'' *'' Aspicilia corallophora'' *'' Aspicilia cuprea'' *'' Aspicilia cyanescens'' *'' Aspicilia desertorum'' *'' Aspicilia dubertretii'' *'' Aspicilia endochlora'' *'' Aspicilia epiglypta'' *'' Aspicilia euphratica'' *'' Aspicilia expansa'' *'' Aspicilia fluviatilis'' *'' Aspicilia fruticulosofoliacea'' *'' Aspicilia fumosa'' *'' Aspicilia granulosa'' *'' Aspicilia grisea'' *'' Aspicilia guadalupensis'' *'' Aspicilia humida'' – South Korea *'' Aspicilia knudsenii'' *'' Aspicilia laevata'' *'' Aspicilia major'' –

Falkland Islands The Falkland Islands (; ), commonly referred to as The Falklands, is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and from Cape Dub ...

*'' Aspicilia nashii'' *'' Aspicilia niesenensis'' *'' Aspicilia ochromelaena'' *'' Aspicilia olivaceobrunnea'' *'' Aspicilia olivaceopallida'' *'' Aspicilia pacifica'' *''

Aspicilia peltastictoides ''Aspicilia'' (sunken disk lichen) is a genus of mostly crustose areolate lichens that grow on rock. Most members have black apothecia discs that are slightly immersed in the areolas, hence the common name"''Field Guide to California Lichens, St ...

Aspicilia verrucigera ''Aspicilia'' (sunken disk lichen) is a genus of mostly crustose areolate lichens that grow on rock. Most members have black apothecia discs that are slightly immersed in the areolas, hence the common name"''Field Guide to California Lichens, St ...

Gallery

Image:Aspicilia_caesiocinerea-2.jpg, '' Aspicilia caesiocinerea'' Image:Aspicilia_cinerea-1.jpg, ''

'' Image:Aspicilia_caesiocinerea-7.jpg, Photograph of a cross section of an apothecium of ''A. caesiocinerea'' taken through a compound microscope, x 100. Note the dark olive epihymenium. Image:Aspicilia cinerea-2.jpg, Photograph of a section of an apothecium of ''A. cinerea'' taken through a compound microscope (x400) showing algae in the amphithecium of the thalline margin. (Lecanorine-type apothecium) Image:Aspicilia caesiocinerea-9.jpg, Photograph of an ascus from ''A. caesiocinerea'' taken through a compound microscope (x1000) showing 8 spores per ascus. (Spores measure approximately 15 x 11 micrometres.)

References

* {{Taxonbar, from=Q4807987 Megasporaceae Lichen genera Pertusariales genera Taxa named by Abramo Bartolommeo Massalongo Taxa described in 1852