''Peltigera'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of approximately 100 species of

foliose Foliose lichen is one of the morphological classes of lichens, which are complex organisms that arise from the symbiotic relationship between fungi and a photosynthetic partner, typically algae. This partnership allows lichen to live in diverse ...

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Peltigeraceae The Peltigeraceae are a family of lichens in the order Peltigerales. The Peltigeraceae, which contains 15 genera and about 600 species, has recently (2018) been emended to include the families Lobariaceae and Nephromataceae. Many Peltigeraceae sp ...

. Commonly known as the dog or pelt lichens, species of ''Peltigera'' are often

terricolous A terricolous lichen is a lichen that grows on the soil as a substrate. An example is some members of the genus ''Peltigera ''Peltigera'' is a genus of approximately 100 species of foliose lichens in the family Peltigeraceae. Commonly known ...

(growing on soil), but can also occur on moss, trees, rocks, and many other substrates in many parts of the world. Most species of ''Peltigera'' have the

cyanobacterium Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...

Nostoc ''Nostoc'', also known as star jelly, troll’s butter, spit of moon, fallen star, witch's butter (not to be confused with the fungi commonly known as witches' butter), and witch’s jelly, is the most common genus of cyanobacteria found in var ...

'' as the dominant

photobiont A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Coccomyxa.'' The presence of both a green alga and a cyanobacterium makes some tripartite; in this case they show

cephalodium {{Short description, Morphological structure found in some lichens Cephalodia (singular cephalodium) are small gall-like structures found in some species of lichens that contain cyanobacterial symbionts Symbiosis (from Greek , , "living toget ...

growths containing the third partner, ''Nostoc''. Because of their ability to fix nitrogen from the atmosphere, such lichens are influential in

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

composition and generation.

Description

Species of ''Peltigera'' are

, with broad lobed thalli. Although the size of the thalli is variable and species-dependent, in some species the thalli can grow quite large, up to 30 cm in diameter.Vitikainen O. (1994). (1998). Taxonomic notes on neotropical species of ''Pelitgera''. In: Lichenology in Latin America: history, current knowledge and applications. Edited by M. P. Marcelli, and M.R.D. Seaward. CETESB, Companhia de Tecnologia de Saneamento Ambiental, Estado de Sao Paulo. pp. 135-139. The color of the upper surface may range from drab gray, brown or greenish. Lower surfaces are typically ''without'' a cortex (unlike other

foliose lichen Foliose lichen is one of the morphological classes of lichens, which are complex organisms that arise from the symbiotic relationship between fungi and a photosynthetic partner, typically algae. This partnership allows lichen to live in diver ...

s),Fioliose lichens, Lichen Thallus Types, Allan Silverside
/ref> and cottony, often with fungal

hyphae 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 or ...

fused to form a network of veins. The reproductive structures isidia,

soredia Soredia are common reproductive structures of lichens. Lichens reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungal hyphae wrapped around cyanobacteria or ...

or lobules may be present in some species. All species of ''Peltigera'' associate with the nitrogen-fixing cyanobacteria ''

''. ''Peltigera'' can be distinguished from the equally large and leaf-like lichen, '' Nephroma'', by its veined lower cortex; ''Nephroma'', by contrast, has a smooth, unveiled lower cortex.

Habitat

''Peltigera'' are mainly ground-dwelling, but can also be found on mosses or dead wood. Some species are used as forest succession indicators.

Taxonomy

In 1753,

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

first described the species ''Lichen apthosus'' and ''L. caninus'' back when all known lichens were grouped into the genus ''Lichen''. Later, in 1787,

Willdenow Carl Ludwig Willdenow (22 August 1765 – 10 July 1812) was a German botanist, pharmacist, and plant taxonomist. He is considered one of the founders of phytogeography, the study of the geographic distribution of plants. Willdenow was also ...

circumscribed the genus ''Peltigera'', and redescribed '' P. aphthosa'' and '' P. canina''. The generic name is derived from the

Latin language Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of ...

''pelta'' (small shield), and refers to the shield-shaped

thallus Thallus (plural: 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. Many of these organisms ...

in these species. The common name, the dog lichen, refers to the perceived resemblance of ''P. caninus'' to a dog.

Phylogeny

In a comparative analysis of both morphological and chemical characteristics as well as sequences of large subunit nuclear

ribosomal DNA Ribosomal DNA (rDNA) is a DNA sequence that codes for ribosomal RNA. These sequences regulate transcription initiation and amplification, and contain both transcribed and non-transcribed spacer segments. In the human genome there are 5 chro ...

, it was shown that the genus ''Peltigera'' is

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...

. Several species, such as '' P. canina'', have been changed to a group as there appears to be several species clustered under a single name.

Distribution

The ''Peltigera'' have a widespread distribution, and are found on all continents. There are 34

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

n species, 30

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

an species, 25 species from

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

, and 16 species from

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

Species

Apfelflechte Peltigera aphtosa OhWeh-005

*''

Peltigera aphthosa ''Peltigera aphthosa'' is a species of lichen known by the common names green dog lichen, leafy lichen, felt lichen, and common freckle pelt. It has a circumpolar distribution, occurring throughout the Arctic, boreal, and temperate regions of the ...

'' *'' Peltigera aquatica'' *'' Peltigera britannica'' *''

Peltigera canina ''Peltigera canina'', commonly known as the dog lichen, is a widely distributed species of foliose lichen in the family Peltigeraceae. It was originally described by Carl Linnaeus in his 1753 work ''Species Plantarum''. German botanist Carl Lud ...

'' *'' Peltigera castanea'' *'' Peltigera chionophila'' *'' Peltigera collina'' *'' Peltigera degenii'' *'' Peltigera didactyla'' *'' Peltigera dilacerata'' *'' Peltigera dolichorhiza'' *'' Peltigera elisabethae'' *'' Peltigera extenuata'' *'' Peltigera fimbriata'' *'' Peltigera gowardii'' *'' Peltigera granulosa'' *'' Peltigera horizontalis'' *'' Peltigera hydrophila'' *'' Peltigera hydrothyria'' *'' Peltigera hymenina'' *'' Peltigera isidiophora'' *'' Peltigera islandica'' *'' Peltigera koponenii'' *'' Peltigera lactucifolia'' *'' Peltigera lairdii'' *'' Peltigera latiloba'' *'' Peltigera lepidophora'' *'' Peltigera leptoderma'' *'' Peltigera leucophlebia'' *'' Peltigera malacea'' *'' Peltigera membranacea'' *'' Peltigera montis-wilhelmii'' *'' Peltigera neckeri'' *'' Peltigera neodegenii'' *'' Peltigera neorufescens '' *'' Peltigera papuana'' *'' Peltigera polydactylon'' *'' Peltigera ponojensis'' *'' Peltigera praetextata'' *'' Peltigera pulverulenta'' *'' Peltigera pusilla'' *'' Peltigera rufescens'' *'' Peltigera scabrosa'' *'' Peltigera scabrosella'' *'' Peltigera seneca'' *'' Peltigera serusiauxii'' *'' Peltigera shennongjiana'' – China *'' Peltigera sorediifera'' *'' Peltigera subhorizontalis'' *'' Peltigera tartarea'' *'' Peltigera tereziana'' *'' Peltigera vainioi'' *'' Peltigera venosa'' *'' Peltigera weberi'' *'' Peltigera wulingensis''

Uses

''Peltigera'' species has been used historically to treat wounds, urinary disorders,

thrush ''The Man from U.N.C.L.E.'' is an American spy fiction television series produced by Metro-Goldwyn-Mayer Television and first broadcast on NBC. The series follows secret agents, played by Robert Vaughn and David McCallum, who work for a secret ...

tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, ...

, and

rabies Rabies is a viral disease that causes encephalitis in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, ...

. '' P. apthosa'' was used as a remedy for cough and infantile aphthae. ''P. furfuracea'' has shown potent antioxidant activity and reducing power. Similarly, ''Peltigera'' specimens from Hawaii and Iceland have also been reported to show pronounced antioxidant activity.

Food source

Although a few reports have described

caribou Reindeer (in North American English, known as caribou if wild and ''reindeer'' if domesticated) are deer in the genus ''Rangifer''. For the last few decades, reindeer were assigned to one species, ''Rangifer tarandus'', with about 10 subspe ...

and

reindeer Reindeer (in North American English, known as caribou if wild and ''reindeer'' if domesticated) are deer in the genus ''Rangifer''. For the last few decades, reindeer were assigned to one species, ''Rangifer tarandus'', with about 10 subs ...

feeding on the thalli of ''Peltigera'', in general, species of ''Peltigera'' are not commonly used as a food source by mammals. A study of the grazing habits of the land snails '' Cantareus aspersa'' and '' Limax'' species revealed that these snails prefer to eat ''Peltigera'' species (such as '' P. praetextata'') that are lacking in secondary metabolites.

Bioactive compounds

'' Peltigera leucophlebia'' contains the compounds tenuiorin and methyl orsellinate, which are inhibitory to the enzyme 15-lipoxygenase. Tenuiorin is also known to occur in '' P. apthosa'', '' P. malacea'' and '' P. neckeri''. A mixture of methyl and ethyl orsellinates have been identified from ''P. aphthosa'' that had

antibacterial An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...

activity against

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bact ...

and -negative bacteria. The novel non-protein

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha ...

s solorinine and peltigerine have been detected in various species of ''Peltigera''.