''Pseudocyphellaria'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of large, leafy

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Brodo, I. M., S. D. Sharnoff, and S. Sharnoff. 2001. ''Lichens of North America''. Yale University Press: New Haven. The genus has a widespread distribution, especially in south

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

regions, and contains about 170 species. They resemble ''

Lobaria ''Lobaria'' is a genus of foliose lichens, formerly classified in the family (biology), family Lobariaceae, but now placed in the Peltigeraceae. They are commonly known as "lung wort" or "lungmoss" as their physical shape somewhat resembles a lu ...

'', except that most species of ''Pseudocyphellaria'' have conspicuous

pseudocyphella Pseudocyphellae (singular ''pseudocyphella'') are structures in lichens that appear as tiny pores on the outer surface (the cortex of the lichen. They are caused when there is a break in the cortex of the lichen, and the medullary hyphae extend t ...

e on their lower surface, a characteristic that was once considered unique to this genus. Some species contain

pulvinic acid Pulvinic acids are natural chemical pigments found in some lichens, derived biosynthetically from the aromatic amino acids phenylalanine and tyrosine, via dimerization and oxidative ring-cleavage of aryl pyruvic acids, a process that also produ ...

-related pigments; in these species the

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 gr ...

and pseudocyphellae can be bright yellow.

Taxonomy

''Pseudocyphellaria'' was originally

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every polyg ...

in 1890 by Finnish lichenologist

Edvard August Vainio Edvard August Vainio (born Edvard Lang; 5 August 185314 May 1929) was a Finnish lichenology, lichenologist. His early works on the lichens of Lapland (Finland), Lapland, his three-volume monograph on the lichen genus ''Cladonia'', and, in parti ...

, with ''P. aurata'' as the

type species In 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 species that contains the biological type specimen ...

. In the 2010s,

molecular phylogenetic 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 ...

analyses showed that this species, along with a few others, nested within a small

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

separate from most ''Pseudocyphellaria''. These species, characterised by a yellow

medulla Medulla or Medullary may refer to: Science * Medulla oblongata, a part of the brain stem * Renal medulla, a part of the kidney * Adrenal medulla, a part of the adrenal gland * Medulla of ovary, a stroma in the center of the ovary * Medulla of t ...

containing

derivatives and fernene

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

s, were placed in a resurrected genus, ''

Crocodia ''Crocodia'' is a genus of foliose lichens in the family Peltigeraceae. It has eight species. The genus has a cosmopolitan distribution, although most species occur in temperate and tropical regions of the Southern Hemisphere. The main character ...

'', while ''Pseudocyphellaria'' was proposed for

conservation Conservation is the preservation or efficient use of resources, or the conservation of various quantities under physical laws. Conservation may also refer to: Environment and natural resources * Nature conservation, the protection and managem ...

with a new type species, '' P. crocata''. This proposal was later accepted by the

Nomenclature Committee for Fungi International Botanical Congress (IBC) is an international meeting of botanists in all scientific fields, authorized by the International Association of Botanical and Mycological Societies (IABMS) and held every six years, with the location rotati ...

The ''Pseudocyphellaria'' symbiosis

Many species of ''Pseudocyphellaria'' are

cyanolichen Cyanolichens are lichens that apart from the basic fungal component ("mycobiont"), contain cyanobacteria, otherwise known as blue-green algae, as the photosynthesizing component ("photobiont"). Overall, about a third of lichen photobionts are cyan ...

s and contain 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, blue ...

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 vari ...

'' as a

photobiont A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.nitrogen fixation Nitrogen fixation is a chemical process by which molecular nitrogen (), with a strong triple covalent bond, in the air is converted into ammonia () or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. Atmo ...

. In some species of ''Pseudocyphellaria'' the cyanobacterium is the sole photobiont, while other species also contain the

green alga The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

'' Dictyochloropsis'' and restrict the cyanobacterium to warty cephalodia on the lower surface of the lichen. Some species of ''Pseudocyphellaria'' appear to be able to use either a cyanobacterium or a green algae as their photobiont. DNA tests have shown that the fungal symbionts in ''P. murrayi'' (which is in a symbiosis with a cyanobacterium) and ''P. rufovirescens'' (which is in a symbiosis with a green alga) are actually the same species. This means that ''P. murrayi''-''P. rufovirescens'' is actually one species of fungus that is capable of forming two very different lichens, one with a cyanobacterium and one with a green alga. Two other possible pairs of ''Pseudocyphellaria'' species that may be capable of choosing their photobiont are ''P. knightii''-''P. lividofusca'', and ''P. kookeri''-''P. durietzii''.

Ecological significance

Most ''Pseudocyphellaria'' grow on trees in coastal areas, from the subtropics to the boreal zones, although some species can occasionally be found growing on mossy rocks or growing inland. Many species of ''Pseudocyphellaria'' are restricted to

old-growth forest An old-growth forestalso termed primary forest, virgin forest, late seral forest, primeval forest, or first-growth forestis a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological featur ...

s in humid areas, and are therefore threatened by logging. The limited light conditions of dense young forests can severely decrease the growth of ''Pseudocyphellaria crocata'' compared to more open, old-growth forests, and the excess of light from clearcuts can also cause damage to the lichen. Because they are often restricted to humid forests in undisturbed areas, species of ''Pseudocyphellaria'' are often used as indicators of valuable old growth forests. ''Pseudocyphellaria rainierensis'' is listed as vulnerable in Canada by COSEWIC. ''Pseudocyphellaria crocata'' has disappeared from much of

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...

, a development that has been partly attributed to an increase in grazing from snails, presumably as a result of global warming. In the areas of Scandinavia where ''P. crocata'' is still found, it seems restricted to growing on smaller twigs that are harder for the snails to reach.

Species

Pseudocyphellaria glabra ''Pseudocyphellaria glabra'' is a species of corticolous (bark-dwelling), foliose lichen in the family Peltigeraceae. It has a pale-green upper thallus surface, a white medulla and white pseudocyphellae (tiny pores for gas exchange). Distribut ...

Traditional use

Several species of ''Pseudocyphellaria'' can be utilized to produce a brown to orange-brown dye,Brough, S. G. 1984. Dye characteristics of British Columbia forest lichens. ''Syesis'' 17: 81–94. and some of them have been used to dye wool in Britain and Scandinavia. Uphof, J. C. T. 1959. ''Dictionary of Economic Plants''. Hafner Publishing Co.: New York. One species of ''Pseudocyphellaria'' is used in Madagascar to make a tea used to treat indigestion. Besides being yellow, pulvinic acid derivatives are highly toxic. Any species of ''Pseudocyphellaria'' that has yellow structures probably contains one of these compounds,Garbarino, J. A., W. Quilhot, M. Piovano, and C. Rubio. 1991. Studies on Chilean lichens. XVIII. Additions to the chemistry of Pseudocyphellaria. ''Boletin De La Sociedad Chilena De Quimica'' 36(4): 229-231. and may be toxic if ingested.

Gallery

Image:Pseudocyphellaria2.jpg, ''Pseudocyphellaria corifolia'' growing in Parque Etnobotanico Omora on

Isla Navarino Navarino Island () is a Chilean island located between Isla Grande de Tierra del Fuego, to the north, and Cape Horn, to the south. The island forms part of the Commune of Cabo de Hornos, the southernmost commune in Chile and in the world, belong ...

, Chile. This species has brown

soralia 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 o ...

and black apothecia. Image:Pseudocyphellaria3.jpg, ''Pseudocyphellaria granulata'' growing in Parque Etnobotanico Omora on

, Chile. This species has brilliant yellow

. Image:Pseudocyphellaria4.jpg, A species of ''Pseudocyphellaria'' growing in the

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

near

Bariloche San Carlos de Bariloche, usually known as Bariloche (), is a city in the province of Río Negro Province, Río Negro, Argentina, situated in the foothills of the Andes on the southern shores of Nahuel Huapi Lake. It is located within the Nahuel ...

, Argentina. This species has brilliant yellow

. Image:Pseudocyphellaria5.jpg, Yellow pseudocyphellea on the underside of a species of ''Pseudocyphellaria'' growing near

, Argentina.