| Methuselah's beard lichen | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Lecanorales |
| Family: | Parmeliaceae |
| Genus: | Dolichousnea |
| Species: | D. longissima |
| Binomial name | |
| Dolichousnea longissima (Ach.) Articus (2004) | |
| Synonyms [1] | |
Dolichousnea longissima (syn. Usnea longissima), [2] [3] commonly known by the names old man's beard or Methuselah's beard lichen, is a fruticose lichen in the family Parmeliaceae.
This lichen is fruticose, with very long stems and short, even side branches. It is considered the longest lichen in the world. [4] The stems are usually 15 to 30 cm in length but are sometimes much longer. [5] It is pale green to silvery-yellow. It has a distinct central cord, which is white. [6]
D. longissima may grow to be 20 feet in length. It predominantly reproduces asexually through fragmentation. Spore-producing structures are rarely observed. [7] It can double its length each year. [8]
Dolichousnea longissima is found in boreal forests and coastal woodland in Europe, Asia, and North America. [9] In North America, it is primarily found on the Pacific Coast, and the largest populations are concentrated in the Pacific Northwest. It ranges from Upper Midwest into Canada, the Great Lakes region, and extends to the coast of the Atlantic ocean. [7] It was historically circumboreal, but has been regionally extirpated from areas of Europe and Scandinavia. [6] It has been placed on the Red List of California Lichens, and is considered Endangered in the Norwegian Red List. [6] [8]
The species grows within the canopies of coniferous trees, primarily those found in old growth Douglas fir forests and near bodies of water. Air pollution heavily affects the metabolic functions of the species, and as a result, populations have declined. [7] Industrial logging has also had detrimental impacts on population numbers. [8]
The species is harvested for decoration. [6] It has also been historically used as a bedding and filtering material. [7] Medicinally, D. longissima is known as an anti-inflammatory due to the presence of the compound longissiminone. [10] It has been described in Chinese herbal medicine dating back to 500 A.D., where one of the names for the species translates to "pine gauze". [4]
Usnea is a genus of mostly pale grayish-green fruticose lichens that grow like leafless mini-shrubs or tassels anchored on bark or twigs. The genus is in the family Parmeliaceae. It grows all over the world. Members of the genus are commonly called old man's beard, beard lichen, or beard moss.
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, Usnea, Parmotrema, and Hypotrachyna.
Lobaria pulmonaria is a large epiphytic lichen consisting of an ascomycete fungus and a green algal partner living together in a symbiotic relationship with a cyanobacterium—a symbiosis involving members of three kingdoms of organisms. Commonly known by various names like tree lungwort, lung lichen, lung moss, lungwort lichen, oak lungs or oak lungwort, it is sensitive to air pollution and is also harmed by habitat loss and changes in forestry practices. Its population has declined across Europe and L. pulmonaria is considered endangered in many lowland areas. The species has a history of use in herbal medicines, and recent research has corroborated some medicinal properties of lichen extracts.
Lethariella is a genus of fruticose lichens in the family Parmeliaceae. The genus was originally proposed as a subgenus of Usnea by Polish lichenologist Józef Motyka in his 1936 monograph of that genus. Norwegian botanist Hildur Krog elevated the taxon to generic status in 1976.
Tuckermannopsis is a genus of foliose lichens in the family Parmeliaceae.
Protousnea is a genus of lichenised ascomycetes in the large family Parmeliaceae. It contains two accepted species. Protousnea species have a fruticose growth form, similar to beard lichens. The genus is endemic to southern South America. The genus was circumscribed in 1976 by Hildur Krog as a segregate genus from Usnea.
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 more mycobionts. Fruticose lichens are not a monophyletic and holophyletic lineage, but is a form encountered in many classes. Fruticose lichens have a complex vegetation structure, and are characterized by an ascending, bushy or pendulous appearance. As with other lichens, many fruticose lichens can endure high degrees of desiccation. They grow slowly and often occur in habitats such as on tree barks, on rock surfaces and on soils in the Arctic and mountain regions.
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. 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.
Usnea strigosa, commonly known as bushy beard lichen, is a fruticose lichen in the family Parmeliaceae.
Usnea articulata, commonly known as the string-of-sausage lichen, is a pale greenish-grey, densely branched lichen with a prostrate or pendant growth form. It grows on bark, on branches and twigs, and is often unattached to a branch and merely draped over it. It grows up to 100 cm (40 in) in length.
Usnea trichodea, commonly known as bony beard lichen, is a pale straw-colored fruticose lichen with a pendant growth form. It grows on trees and is native to eastern North America.
Usnea florida is a species of beard lichen in the family Parmeliaceae. It was first described by Carl Linnaeus in his 1753 work Species Plantarum. German botanist Friedrich Heinrich Wiggers transferred it to the genus Usnea in 1780. It is considered a threatened or vulnerable species in several European countries.
Usnea glabrescens is a species of beard lichen in the family Parmeliaceae. It grows on bark, has a shrubby thallus with a blackened base, and a thick cortex. Several chemotypes of this species have been reported. The lichen is widely distributed in Europe.
Dolichousnea is a genus of fruticose lichens in the family Parmeliaceae. It has three species. The widely distributed type species, Dolichousnea longissima, is found in boreal regions of Asia, Europe, and North America.
Usnea poliothrix is an irregular, orange species of Usnea, a common fruticose lichen. It has soralia with prominent isidiofibril growth. Its orange cortex is very fragile, and often scarred by the marks of lost isidiofibrils. Although often characterized in literature as U. poliotrix, it was officially named U. poliothrix in 1874 by German lichenologist August von Krempelhuber.
Usnea vainioi is a rare species of beard lichen in the family Parmeliaceae found in the southeastern United States. It was described as a new species in 1936 by Polish lichenologist Józef Motyka. The specific epithet honours Finnish lichenologist Edvard August Vainio. The lichen contains diffractaic acid as the main secondary compound.
Philippe Clerc is a Swiss lichenologist. A Festschrift was dedicated to him in 2020, on the occasion of his retirement from the Conservatory and Botanical Garden of the City of Geneva, where he worked from 1993 to 2020. Clerc is an authority on the beard lichens, and has had nearly 100 publications on this and other topics, such as the lichen flora of Switzerland.
Usnea leana is a species of fruticose lichen in the family Parmeliaceae. Found in the Galápagos Islands, it characterized by its pendulous thallus, branches covered with point-like pseudocyphellae, and the presence of galbinic acid. This lichen is currently known to be endemic to the Galápagos, with only two known localities representing its distribution.
Usnea mayrhoferi is a species of fruticose lichen in the family Parmeliaceae. It is found in the Galápagos Islands.
Usnea patriciana is a rare species of fruticose lichen in the family Parmeliaceae. It is endemic to the Galápagos Islands. This beard lichen has a shrubby appearance with cylindrical branches and distinct black pigmentation at its base.