A lichen is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. Lichens are important actors in nutrient cycling and act as producers which many higher trophic feeders feed on, such as reindeer, gastropods, nematodes, mites, and springtails. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not plants. They may have tiny, leafless branches (fruticose); flat leaf-like structures (foliose); grow crust-like, adhering tightly to a surface (substrate) like a thick coat of paint (crustose); have a powder-like appearance (leprose); or other growth forms.
Peltigera is a genus of approximately 100 species of foliose lichens in the family Peltigeraceae. Commonly known as the dog or pelt lichens, species of Peltigera are often terricolous, but can also occur on moss, trees, rocks, and many other substrates in many parts of the world.
Peltigerales is an order of lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. The taxonomy of the group has seen numerous changes; it was formerly often treated as a suborder of the order Lecanorales. It contains two suborders, eight families and about 45 genera such as Lobaria and Peltigera.
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.
Nephroma is a genus of medium to large foliose lichens. The genus has a widespread distribution. They are sometimes called kidney lichens, named after the characteristic kidney-shaped apothecia that they produce on the lower surface of their lobe tips, which often curl upwards and thus are visible from above. Sterile specimens that do not have apothecia can look somewhat like Melanelia, Peltigera, Platismatia, or Asahinea. Most species grow either on mossy ground or rocks, or on trees.
Peltigera membranacea is a species of lichenized fungus in the family Peltigeraceae. It has a foliose growth pattern, with what appear to be veins in the leaf-like parts, but these do not have a vascular function. The apothecia are erect, numerous, and often a bright brown-orange in colour. Some simple sequence repeat markers have been developed for both the fungal partner (mycobiont) of Peltigera membranacea and its Nostoc photobiont partner; these allow for both population genetic studies and an alternative means of identifying between P. membranacea and its lookalikes.
Pannaria phyllidiata is a species of lichen in the family Pannariaceae. Known from Australia, it was described as new to science in 2011. It is characterised by its unique phyllidia and distinct distribution.
Sticta venosa is a species of terricolous (ground-dwelling), foliose lichen in the family Peltigeraceae. It is known only from Pichincha Province, Ecuador, and from Colombia. It was described as new to science in 2011.
A foliose lichen is a lichen with flat, leaf-like lobes, which are generally not firmly bonded to the substrate on which it grows. It is one of the three most common growth forms of lichens. It typically has distinct upper and lower surfaces, each of which is usually covered with a cortex; some, however, lack a lower cortex. The photobiont layer lies just below the upper cortex. Where present, the lower cortex is usually dark, but occasionally white. Foliose lichens are attached to their substrate either by hyphae extending from the cortex or medulla, or by root-like structures called rhizines. The latter, which are found only in foliose lichens, come in a variety of shapes, the specifics of which can aid in species identification. Some foliose lichens attach only at a single stout peg called a holdfast, typically located near the lichen's centre. Lichens with this structure are called "umbilicate". In general, medium to large epiphytic foliose lichens are moderately sensitive to air pollution, while smaller or ground-dwelling foliose lichens are more tolerant. The term "foliose" derives from the Latin word foliosus, meaning "leafy".
Lichens are symbiotic organisms made up of multiple species: a fungus, one or more photobionts and sometimes a yeast. They are regularly grouped by their external appearance – a characteristic known as their growth form. This form, which is based on the appearance of vegetative part of the lichen, varies depending on the species and the environmental conditions it faces. Those who study lichens (lichenologists) have described a dozen of these forms: areolate, byssoid, calicioid, cladoniform, crustose, filamentous, foliose, fruticose, gelatinous, leprose, placoidioid and squamulose. Traditionally, crustose (flat), foliose (leafy) and fruticose (shrubby) are considered to be the three main forms. In addition to these more formalised, traditional growth types, there are a handful of informal types named for their resemblance to the lichens of specific genera. These include alectorioid, catapyrenioid, cetrarioid, hypogymnioid, parmelioid and usneoid.
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 Ludwig Willdenow transferred it to the genus Peltigera in 1787. This species is currently undergoing research as it is likely multiple species under one united name.
Peltigera venosa, commonly known as the fan lichen, is a species of foliose lichen in the family Peltigeraceae. It was first described by Carl Linnaeus in his 1753 work Species Plantarum as Lichen venosus. German botanist Georg Franz Hoffmann transferred it to the genus Peltigera in 1789. P. venosa can be found in temperate and boreal regions of North America, Europe, and Asia, while occasionally being found in drier climates such as mountainous Arizona.
Otto Vernon Darbishire was a British botanist who specialised in marine algae and lichens. Born in Conwy, he was educated at several places and eventually graduated from the University of Oxford.
Punctelia perreticulata is a widely distributed species of foliose lichen in the family Parmeliaceae. It occurs in Mediterranean Europe and Russia, North America, South America, Australia, and New Zealand, where it grows on rocks, bark, or wood. Its main distinguishing features are its thallus surface, marked with many shallow depressions, grooves, or pits, and sorediate pseudocyphellae. The lower side of the thallus is ivory to tan towards the centre and the major secondary metabolite in the medulla is lecanoric acid. A lookalike species with which it has been historically confused is Punctelia subrudecta; this lichen can be distinguished from Punctelia perreticulata by the texture of the thallus surface, or, more reliably, by the length of its conidia.
Peltigera neckeri is a foliose lichen in the family Peltigeraceae. It is commonly called black saddle pelt. It is distinguished by its unique tubular apothecia, which resemble black saddles or painted finger nails.
Peltigera gowardii, or western waterfan, is an aquatic lichen found only in mountain streams of Western North America. It is the largest aquatic lichen in the Pacific Northwest.
Yoshimuriella is a genus of foliose (leafy) lichens in the family Peltigeraceae. It has nine species.
Peltigera rufescens, commonly known as the field dog lichen, is a species of terricolous (ground-dwelling), foliose lichen in the family Peltigeraceae. The common and widespread species has a cosmopolitan distribution.
Peltigera wulingensis is a species of terricolous (ground-dwelling), foliose lichen in the family Peltigeraceae. Originally described from specimens found in northern China, it has since been recorded in Canada, Norway, and Russia.
Peltigera fimbriata is a species of foliose lichen in the family Peltigeraceae. Found in Papua New Guinea, it was formally described as a new species in 2009 by lichenologists Orvo Vitikainen, Emmanuël Sérusiaux, Bernard Goffinet, and Jolanta Miądlikowska. The type specimen was collected between Mt. Sarawaket Southern Range and Iloko village The species epithet fimbriata refers to the characteristic long hairs that occur on the upper thallus surface.
