''Lepraria'' 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
leprose (powdery)
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 ...
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 grows on its
substrate
Substrate may refer to:
Physical layers
*Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached
** Substrate (aquatic environment), the earthy material that exi ...
like patches of granular, caked up, mealy dust grains.
[A taxonomic revision of the North American species of Lepraria s.l. that produce divaricatic acid, with notes on the type species of the genus L. incana, James C. Lendemer
, Mycologia 103(6): 1216-1229]
/ref>[ Members of the genus are List of lichen common names and their genera, commonly called dust lichens.][Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, ][Dust Lichen (Lepraria), Encyclopedia of Life]
/ref>[USDA Natural Resources Conservation Service Name Search]
/ref> The main vegetative body (thallus
Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...
) is made of patches of 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 ...
(little balls of algae wrapped in fungus).[ There are no known mechanisms for ]sexual reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote tha ...
, yet members of the genus continue to speciate
Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...
.[ Some species can form marginal lobes and appear ]squamulose
A squamulose lichen is a lichen that is composed of small, often overlapping "scales" called . If they are raised from the substrate and appear leafy, the lichen may appear to be a foliose lichen, but the underside does not have a "skin" (cortex) ...
.[ Because of the morphological simplicity of the thallus and the absence of sexual structures, the composition of ]lichen product
Lichen products, also known as lichen substances, are organic compounds produced by a lichen. Specifically, they are secondary metabolites. Lichen products are represented in several different chemical classes, including terpenoids, orcinol deri ...
s (i.e., 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 made by lichens) are important characters
Character or Characters may refer to:
Arts, entertainment, and media Literature
* ''Character'' (novel), a 1936 Dutch novel by Ferdinand Bordewijk
* ''Characters'' (Theophrastus), a classical Greek set of character sketches attributed to Theoph ...
to distinguish between similar species in ''Lepraria''.
Taxonomy
''Lepraria'' was circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle.
* Circum ...
in 1803 by Swedish lichenologist Erik Acharius
Erik Acharius (10 October 1757 – 14 August 1819) was a Swedish botanist who pioneered the Taxonomy (biology), taxonomy of lichens and is known as the "father of lichenology". Acharius was famously the last pupil of Carl Linnaeus.
Life
Ac ...
. Jack Laundon
Jack Rodney Laundon (28 July 1934 – 31 December 2016) was a British lichenologist and became president of the British Lichen Society.
Education and personal life
Jack Rodney Laundon was born 28 July 1934 in Kettering, Northamptonshire. He wa ...
assigned ''Lepraria incana
''Lepraria incana'' is a species of dust lichen in the family Stereocaulaceae. First described scientifically by Johann Jacob Dillenius in 1741, and then formally by Carl Linnaeus in 1753, it is the type species of the genus ''Lepraria''. ...
'' as the type species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
of the genus in 1992. It is in the family Stereocaulaceae
The Stereocaulaceae are a family of lichen-forming fungi in the order Lecanorales. It contains five genera. Species of this family are widely distributed in temperate boreal and austral regions.
Genera
*'' Hertelidea'' – 6 spp.
*''Lepraria ...
.
The taxonomy of ''Lepraria'' has undergone significant changes as new research methods have become available. Historically, some species now classified as ''Lepraria'' were placed in a separate genus called ''Leproloma
''Lepraria'' 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 clas ...
'', which was thought to be distinct based on features such as whitish colouring with yellow tints, a powdery surface composed of small lobes, and specific chemical compounds called dibenzofuran
Dibenzofuran (DBF) is a heterocyclic organic compound with the chemical structure shown at right. It is an aromatic compound that has two benzene rings fused to a central furan ring. All the numbered carbon atoms have a hydrogen atom bonded to each ...
s. However, molecular
A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...
studies in 2002 showed that most species from both genera are actually part of the same evolutionary group.
Scientists use multiple characteristics to identify and classify ''Lepraria'' species, including their physical appearance (morphology
Morphology, from the Greek and meaning "study of shape", may refer to:
Disciplines
*Morphology (archaeology), study of the shapes or forms of artifacts
*Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...
), their chemical composition, and their genetic sequences. Different populations of the same species can have varying chemical compositions, known as . This variation has led to debate among researchers about how to properly define species boundaries within the genus. While some researchers have proposed splitting the genus into many narrowly defined species based on small genetic or chemical differences, others advocate for a more conservative approach that considers multiple lines of evidence.
Description
Species of ''Lepraria'' are characterised by their powdery, 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 ...
thalli, which are composed almost entirely of 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 ...
—small, granular clusters of fungal and algal cells that allow for asexual reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the f ...
. The thallus
Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...
may appear loosely attached or more firmly integrated with the substrate
Substrate may refer to:
Physical layers
*Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached
** Substrate (aquatic environment), the earthy material that exi ...
, forming irregular, diffuse patches or well-defined, margins. Most species exhibit shades of grey, greenish-grey, or cream, lacking the bright pigmentation seen in some other lichens.
Unlike many lichen-forming fungi, ''Lepraria'' species do not produce fruiting bodies (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 ...
) or sexual spores (ascospore
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 (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...
s). Instead, their reproduction relies entirely on soredia dispersal. In some species, the soredia aggregate into larger clusters known as , which may give the thallus a rough or granular texture. Some species, particularly those in wetter or more sheltered environments, may develop a cottony or membranous appearance. The thallus can also have a —a weft of fungal hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one o ...
e at the base—ranging in colour from white to dark brown or black.
The genus ''Lepraria'' is chemically diverse, with species producing a wide range of 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, including depside
A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester group. Depsides are most often found in lichens, but have also been isolated from higher plants, including species of the Ericaceae, ...
s, depsidone
Depsidones (+ " depside" + "one") are chemical compounds that are sometimes found as secondary metabolites in lichens. They are esters that are both depsides and cyclic ethers. An example is norstictic acid
Norstictic acid is a depsidone produ ...
s, aliphatic
In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated (in which all ...
acids, and terpenoid
The terpenoids, also known as isoprenoids, are a class of naturally occurring organic compound, organic chemicals derived from the 5-carbon compound isoprene and its derivatives called terpenes, diterpenes, etc. While sometimes used interchangeabl ...
s. These substances, detectable through thin-layer chromatography
Thin-layer chromatography (TLC) is a chromatography technique that separates components in non-volatile mixtures.
It is performed on a TLC plate made up of a non-reactive solid coated with a thin layer of adsorbent material. This is called the sta ...
, are often the primary basis for distinguishing species. Many species grow in humid, shaded environments such as tree bark, moss-covered rocks, and soil, although some are found in more exposed, dry habitats.
Molecular phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
studies have refined the circumscription of ''Lepraria''. Several species formerly included in the genus, particularly those producing usnic acid
Usnic acid is a naturally occurring dibenzofuran derivative found in several lichen species with the formula C18H16O7. It was first isolated by German scientist W. Knop in 1844 and first synthesized between 1933 and 1937 by Frank H. Curd and Al ...
, have been reassigned to other genera within the Lecanoromycetes
Lecanoromycetes is the largest class of lichenized fungi. It belongs to the subphylum Pezizomycotina in the phylum Ascomycota. The asci (spore-bearing cells) of the Lecanoromycetes most often release spores by rostrate dehiscence.
The group is ...
, including ''Lecanora
''Lecanora'' is a genus of lichen commonly called rim lichens.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, Lichens in the genus '' Squamarina'' are also called rim lichens. Members of the genus have roughly c ...
'' and '' Leprocaulon''. This reclassification has clarified ''Lepraria'' as a lineage most closely related to the family Stereocaulaceae
The Stereocaulaceae are a family of lichen-forming fungi in the order Lecanorales. It contains five genera. Species of this family are widely distributed in temperate boreal and austral regions.
Genera
*'' Hertelidea'' – 6 spp.
*''Lepraria ...
.
Habitat, distribution, and ecology
''Lepraria'' species occupy a wide range of habitats but are most commonly found in shaded, humid environments where direct rainfall is limited. Many species grow on tree bark, moss
Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...
-covered rocks, or decaying wood, particularly in forests with stable humidity levels. Some taxa
In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...
prefer rocky substrates, particularly siliceous
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant ...
or 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 ...
surfaces, and can colonise cracks or overhangs where they are partially sheltered. Other species thrive on soil, mosses, or plant debris, often in montane
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...
or subalpine
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...
environments.
While ''Lepraria'' is often associated with moist microhabitat
In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...
s, certain species tolerate or even prefer more exposed conditions, such as sunlit rock face
In geography and geology, a cliff or rock face is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. Cliffs are comm ...
s or dry forest floor
The forest floor, also called detritus or wikt:duff#Noun 2, duff, is the part of a forest ecosystem that mediates between the living, aboveground portion of the forest and the mineral soil, principally composed of dead and decaying plant matter ...
s. Some species are pioneers in disturbed habitat
In ecology, a disturbance is a change in environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements ...
s, rapidly colonising exposed surfaces where competition from other lichens or plants is low. In contrast, others show a preference for mature forests with stable microclimates, particularly in 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 ...
regions.
The genus has a broad geographical distribution, occurring on every continent, including Antarctica. The highest species diversity is found in temperate zones, but representatives of ''Lepraria'' are also common in tropical
The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...
and boreal forest
Taiga or tayga ( ; , ), also known as boreal forest or snow forest, is a biome characterized by pinophyta, coniferous forests consisting mostly of pines, spruces, and larches. The taiga, or boreal forest, is the world's largest land biome. I ...
s, alpine
Alpine may refer to any mountainous region. It may also refer to:
Places Europe
* Alps, a European mountain range
** Alpine states, which overlap with the European range
Australia
* Alpine, New South Wales, a Northern Village
* Alpine National P ...
regions, and oceanic islands. Some species exhibit narrow ecological preferences and are restricted to specific regions or substrate types, while others are cosmopolitan
Cosmopolitan may refer to:
Internationalism
* World citizen, one who eschews traditional geopolitical divisions derived from national citizenship
* Cosmopolitanism, the idea that all of humanity belongs to a single moral community
* Cosmopolitan ...
in their distribution. In 2011, 27 species were reported to occur in South America.
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 ...
(in the Catalogue of Life
The Catalogue of Life (CoL) is an online database that provides an index of known species of animals, plants, fungi, and microorganisms. It was created in 2001 as a partnership between the global Species 2000 and the American Integrated Taxono ...
) accepts 85 species of ''Lepraria''.
*'' Lepraria achariana'' – South America
*'' Lepraria alba''
*'' Lepraria albicans''
*'' Lepraria alpina''
*'' Lepraria alternata'' – Australia
*'' Lepraria arbuscula''
*'' Lepraria atlantica''
*'' Lepraria aurescens'' – Thailand
*'' Lepraria barbatica''
*'' Lepraria bergensis''
*'' Lepraria borealis''
*'' Lepraria brasiliensis''
*'' Lepraria brodoi'' – North America
*'' Lepraria cacuminum''
*'' Lepraria caesiella''
*'' Lepraria caesioalba''
*'' Lepraria celata''
*'' Lepraria chileana'' – Chile
*'' Lepraria congesta''
*'' Lepraria crassissima''
*'' Lepraria cryophila''
*'' Lepraria cryptovouauxii''
*'' Lepraria cupressicola''
*'' Lepraria dibenzofuranica'' – Australia
*'' Lepraria diffusa''
*'' Lepraria disjuncta''
*'' Lepraria ecorticata''
*'' Lepraria elobata''
*'' Lepraria finkii''
*''Lepraria friabilis
''Lepraria friabilis'' is a species of leprose lichen in the family Stereocaulaceae. It has a disjunct distribution in the southeastern United States and southern California, where it grows exclusively on coniferous bark in humid environments s ...
''
*'' Lepraria gelida''
*'' Lepraria glaucosorediata''
*'' Lepraria goughensis''
*''Lepraria gracilescens
''Lepraria'' is a genus of leprose (powdery) crustose lichens that grows on its substrate like patches of granular, caked up, mealy dust grains.A taxonomic revision of the North American species of Lepraria s.l. that produce divaricatic acid, w ...
''
*'' Lepraria granulata'' – Eastern and Central Europe
*'' Lepraria granulosa''
*'' Lepraria harrisiana''
*'' Lepraria hodkinsoniana''
*'' Lepraria humida''
*'' Lepraria impossibilis''
*''Lepraria incana
''Lepraria incana'' is a species of dust lichen in the family Stereocaulaceae. First described scientifically by Johann Jacob Dillenius in 1741, and then formally by Carl Linnaeus in 1753, it is the type species of the genus ''Lepraria''. ...
''
*'' Lepraria indica'' – India
*'' Lepraria isidiata''
*'' Lepraria jackii''
*'' Lepraria juanfernandezii''
*'' Lepraria lanata''
*'' Lepraria larrainiana'' – Chile
*'' Lepraria lecanorica''
*'' Lepraria lendemeri''
*'' Lepraria leprolomopsis''
*'' Lepraria leuckertiana''
*'' Lepraria lobata'' – Australia
*''Lepraria lobificans
''Lepraria'' is a genus of leprose (powdery) crustose lichens that grows on its substrate like patches of granular, caked up, mealy dust grains.A taxonomic revision of the North American species of Lepraria s.l. that produce divaricatic acid, w ...
''
*'' Lepraria maderensis''
*'' Lepraria malouina'' – 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 ...
*'' Lepraria membranacea''
*'' Lepraria methylbarbatica''
*'' Lepraria multiacida'' – Brazil
*''Lepraria neojackii
''Lepraria'' is a genus of leprose (powdery) crustose lichens that grows on its substrate like patches of granular, caked up, mealy dust grains.A taxonomic revision of the North American species of Lepraria s.l. that produce divaricatic acid, w ...
'' – South America
*'' Lepraria neozelandica'' – New Zealand
*'' Lepraria nigrocincta''
*'' Lepraria nivalis''
*'' Lepraria normandinoides''
*'' Lepraria nothofagi''
*'' Lepraria nylanderiana''
*'' Lepraria ohmiensis'' – Japan
*'' Lepraria oxybapha''
*'' Lepraria pacifica''
*'' Lepraria pallida''
*'' Lepraria pseudoarbuscula''
*'' Lepraria pulchra'' – Thailand
*'' Lepraria rigidula''
*'' Lepraria salazinica''
*'' Lepraria santosii''
*'' Lepraria sekikaica'' – Australia
*'' Lepraria sipmaniana''
*'' Lepraria squamatica'' – Australia
*'' Lepraria subalbicans''
*'' Lepraria sulphurella''
*'' Lepraria svalbardensis''
*'' Lepraria sylvicola''
*'' Lepraria tenella''
*'' Lepraria toilenae''
*'' Lepraria torii''
*'' Lepraria umbricola''
*'' Lepraria ulrikii'' – Australasia
*'' Lepraria vouauxii''
*'' Lepraria xanthonica''
*'' Lepraria xerophila''
*'' Lepraria zeorinica''
References
{{Taxonbar , from1=Q6527811 , from2=Q61989003 , from3=Q10557818
Lichen genera
Lecanorales genera
Taxa named by Erik Acharius
Taxa described in 1803