Peltigera
Encyclopedia
Peltigera is a genus of approximately 91 species of lichen
ized fungi in the family
Peltigeraceae
.
Commonly known as the dog lichen, lichens of Peltigera are often terricolous (growing on soil), but can also occur on moss, trees, rocks, and many other substrates in many parts of the world. Many Peltigera species are cyanolichens (having a cyanobacteria symbiont), but some Peltigera spp. have only an algae symbiont, and others have both. Because of their ability to fix nitrogen
from the atmosphere, such lichens are influential in soil
composition and generation.
, soredia
or lobules may be present in some species.
All species of Peltigera associate with the nitrogen-fixing cyanobacteria Nostoc
.
, P. didactyla was found growing extensively on ash from volcanic eruptions that occurred in the late 1960s and 1970.
circumscribed the genus Peltigera, and redescribed P. aphthosa and P. canina.
The generic name is derived from the Latin language
pelta (small shield), and refers to the shield-shaped thallus in these species. The common name, the dog lichen, refers to the perceived resemblance of P. caninus to a dog.
, it was shown that the genus Peltigera is monophyletic.
n species, 30 Europe
an species, 25 species from South America
, and 16 species from New Zealand
.
, tuberculosis
, and rabies
. P. apthosa was used as a remedy for cough and infantile aphthae.
P. furfuracea has shown potent antioxidant activity and reducing power.
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 prefers to eat Peltigera species (such as P. praetextata) lacking in secondary metabolites.
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 activity against Gram-positive and -negative bacteria. The novel non-protein amino acid
s solorinine and peltigerine have been detected in various species of Peltigera.
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
ized fungi in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Peltigeraceae
Peltigeraceae
The Peltigeraceae are a lichenized family of fungi in the order Peltigerales. Species of this family have a widespread distribution but are especially prevalent in temperate regions. The family contains two genera and 101 species....
.
Commonly known as the dog lichen, lichens of Peltigera are often terricolous (growing on soil), but can also occur on moss, trees, rocks, and many other substrates in many parts of the world. Many Peltigera species are cyanolichens (having a cyanobacteria symbiont), but some Peltigera spp. have only an algae symbiont, and others have both. Because of their ability to fix nitrogen
Nitrogen fixation
Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen in the atmosphere is converted into ammonia . This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and...
from the atmosphere, such lichens are influential in soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
composition and generation.
Description
Species of Peltigera are foliose, 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. Although some species have small thalli, in others the thalli may The color of the upper surface may range from drab gray, brown or greenish. Lower surfaces are typically without a cortex, and cottony, often with fungal hyphae fused to form a network of veins. The reproductive structures isidiaIsidium
An isidium is a vegetative reproductive structure present in some lichens. Isidia are outgrowths of the thallus surface, and are corticated , usually with a columnar structure, and consisting of both fungal hyphae and algal cells...
, soredia
Soredium
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 green algae. Fungal hyphae make up the basic body...
or lobules may be present in some species.
All species of Peltigera associate with the nitrogen-fixing cyanobacteria Nostoc
Nostoc
Nostoc is a genus of cyanobacteria found in a variety of environmental niches that forms colonies composed of filaments of moniliform cells in a gelatinous sheath.The name "Nostoc" was invented by Paracelsus...
.
Habitat
At Deception Island in the South Shetlands archipelagoArchipelago
An archipelago , sometimes called an island group, is a chain or cluster of islands. The word archipelago is derived from the Greek ἄρχι- – arkhi- and πέλαγος – pélagos through the Italian arcipelago...
, P. didactyla was found growing extensively on ash from volcanic eruptions that occurred in the late 1960s and 1970.
Taxonomy
In 1753, Linnaeus first described the species Lichen apthosus and L. caninus back when all known lichens were grouped into the genus Lichen. Later, in 1787, WilldenowCarl Ludwig Willdenow
Carl Ludwig Willdenow 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...
circumscribed the genus Peltigera, and redescribed P. aphthosa and P. canina.
The generic name is derived from the Latin language
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
pelta (small shield), and refers to the shield-shaped thallus 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 DNARibosomal DNA
Ribosomal DNA codes for ribosomal RNA. The ribosome is an intracellular macromolecule that produces proteins or polypeptide chains. The ribosome itself consists of a composite of proteins and RNA. As shown in the figure, rDNA consists of a tandem repeat of a unit segment, an operon, composed of...
, it was shown that the genus Peltigera is monophyletic.
Distribution
The Peltigera have a widespread distribution, and are found on all continents. There are 34 North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n species, 30 Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
an species, 25 species from South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, and 16 species from New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
.
Uses
Peltigera species has been used historically to treat wounds, urinary disorders, thrushCandidiasis
Thrush redirects here. For the hoof infection see Thrush .Candidiasis or thrush is a fungal infection of any of the Candida species , of which Candida albicans is the most common...
, tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
, and rabies
Rabies
Rabies is a viral disease that causes acute encephalitis in warm-blooded animals. It is zoonotic , most commonly by a bite from an infected animal. For a human, rabies is almost invariably fatal if post-exposure prophylaxis is not administered prior to the onset of severe symptoms...
. P. apthosa was used as a remedy for cough and infantile aphthae.
P. furfuracea has shown potent antioxidant activity and reducing power.
Food source
Although a few reports have described caribou and reindeerReindeer
The reindeer , also known as the caribou in North America, is a deer from the Arctic and Subarctic, including both resident and migratory populations. While overall widespread and numerous, some of its subspecies are rare and one has already gone extinct.Reindeer vary considerably in color and size...
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
Limax
Limax is a genus of air-breathing land slugs, terrestrial pulmonate gastropod mollusks in the family Limacidae.The generic name Limax literally means "slug"....
species revealed that these snails prefers to eat Peltigera species (such as P. praetextata) lacking in secondary metabolites.
Bioactive compounds
Peltigera leucophlebiaPeltigera leucophlebia
Peltigera leucophlebia is a lichenized fungus in the family Peltigeraceae. It is commonly called Ruffled Freckled Pelt. This and other species in the genus contain a green algae in the genus Coccomyxa and also cyanobacteria in the genus Nostoc as symbionts.The thallus of this lichen is gray or...
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 activity against Gram-positive and -negative bacteria. The novel non-protein amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s solorinine and peltigerine have been detected in various species of Peltigera.