''Pseudevernia'' 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 ...

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 diverse ...

s in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Parmeliaceae The Parmeliaceae is a large and diverse family of Lecanoromycetes. With over 2700 species in 71 genera, it is the largest family of lichen-forming fungi. The most speciose genera in the family are the well-known groups: '' Xanthoparmelia'' ( 822 ...

. 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 ...

of the genus, ''

Pseudevernia furfuracea ''Pseudevernia furfuracea'', commonly known as tree moss, is a lichenized species of fungus that grows on the bark of firs and pines. The lichen is rather sensitive to air pollution, its presence usually indicating good air conditions in the grow ...

'' ( commonly known as tree moss), has substantial commercial value in the

perfume industry Perfume (, ; french: parfum) is a mixture of fragrant essential oils or aroma compounds (fragrances), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agreeable scent. The ...

Systematics

''Pseudevernia'' was

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 ...

by German botanist Friedrich Wilhelm Zopf in 1903 with ''

'' as the

. ''Pseudevernia'' is a member of the Hypogymnioid

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, ...

of the family Parmeliaceae; this clade, which also includes the genera ''

Arctoparmelia ''Arctoparmelia'' is a genus of ring lichens in the family Parmeliaceae. The genus was circumscribed by American lichenologist Mason Hale Mason Ellsworth Hale, Jr. (September 23, 1929 – April 23, 1990) was one of the most prolific lichenol ...

'', ''

Brodoa ''Brodoa'' is a genus of three species of foliose lichens in the family Parmeliaceae. The genus, circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon ...

'', and ''

Hypogymnia ''Hypogymnia'' is a genus of foliose lichens in the family Parmeliaceae. They are commonly known as tube lichens, bone lichens, or pillow lichens. Most species lack rhizines (root-like attachment organs on the lower surface) that are otherwise c ...

'', is an evolutionary lineage comprising species occurring in

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 ...

to subpolar regions in both hemispheres. ''Pseudevernia'' has been estimated to have diverged from its closest ancestors during the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

at 31.43 Ma, and is the earliest-diverging member of the Hypogymnioid clade.

Description

''Pseudevernia'' lichens generally have a foliose (leafy)

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 wer ...

, although occasionally it becomes almost

fruticose A fruticose lichen is a form of lichen fungi that is characterized by a coral-like shrubby or bushy growth structure. It is formed from a symbiotic relationship of a photobiont such as green algae or less commonly cyanobacteria and one, two or mor ...

in form. This is the case with ''P. cladonia'', which has intricately branched lobes about 1 mm wide; the lobes of most other ''Pseudevernia'' species are 2–4 mm wide. The lower surface of the thallus often darkens to a purplish-black or mottled white colour, a striking feature that is characteristic of this genus. Several secondary chemicals are produced amongst ''Pseudevernia'' lichens. All species in the genus produce atranorin in the cortex, while

lecanoric acid Lecanoric acid is a chemical produced by several species of lichen.ubChem - Lecanoric acid"> Lecanoric acid is classified as a polyphenol and a didepside and it functions as an antioxidant. The acid is named after the lichen ''Lecanora''. The acid ...

, physodic acid, and olivetoric acid occur in the medullae of some species.

Species

Pseudevernia consocians and cladonia - Flickr - pellaea

*'' Pseudevernia alectoronica'' Egan (2016) – Mexico *'' Pseudevernia cladonia'' (Tuck.) Hale & W.L.Culb. (1966) – eastern North America; Dominican Republic *'' Pseudevernia confusa'' (Du Rietz) R.Schub. & Klem. (1966) *'' Pseudevernia consocians'' (Vain.) Hale & W.L.Culb. (1966) – North America *''

'' (L.) Zopf (1903) – cosmopolitan *'' Pseudevernia intensa'' (Nyl.) Hale & W.L.Culb. (1966) – North America *'' Pseudevernia isidiophora'' (Zopf) Zopf (1903) *'' Pseudevernia mexicana'' Egan (2016) *'' Pseudevernia soralifera'' (Bitter) Zopf (1903) – Europe Some species once classified in ''Pseudevernia'' have since been reduced to synonymy with other species, or have been transferred to other genera. These include: *''Pseudevernia cirrhata'' is now known as '' Hypotrachyna cirrhata''. *''Pseudevernia kamerunensis'' is now known as '' Hypotrachyna sorocheila''. *''Pseudevernia molliuscula'' and ''Pseudevernia thamnidiella'' are synonymous '' Xanthoparmelia molliuscula''. *''Pseudevernia olivetorina'' and ''Pseudevernia ericetorum'' have been folded into synonymy with ''Pseudevernia furfuracea''. *''Pseudevernia mauritiana'' is synonymous with '' Parmelia microblasta''. *''Pseudevernia polita'' is now '' Parmotrema cetratum''.

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 ...

analysis suggests that the North American species ''P. consocians'' and ''P. intensa'' do not form separate

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 gro ...

groups, and so might be the same species.

References

Cited literature

* {{Taxonbar, from=Q7254355 Parmeliaceae Lichen genera Lecanorales genera Taxa named by Friedrich Wilhelm Zopf Taxa described in 1903