Cetradonia

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Cetradonia
Cetradonia linearis - Flickr - pellaea (2).jpg
Cetradonia linearis
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Lecanorales
Family: Cladoniaceae
Genus: Cetradonia
J.C.Wei & Ahti (2002)
Species:
C. linearis
Binomial name
Cetradonia linearis
(A.Evans) J.C.Wei & Ahti (2002)
Synonyms [1]

Cetradonia is a lichen genus in the family Cladoniaceae. A monotypic genus, Cetradonia contains the single species Cetradonia linearis (formerly known as Cladonia linearis and as Gymnoderma lineare). The genus was circumscribed in 2002 by Jiang-Chun Wei and Teuvo Ahti. [2] The genus was once placed in the family Cetradoniaceae (created in 2002) until that family was subsumed into the Cladoniaceae in 2006. [3]

Cetradonia linearis, commonly known as the rock gnome lichen, is a squamulose lichen found in the higher elevations of the southern Appalachian Mountains. Populations are only known to exist in Georgia, North Carolina, South Carolina and Tennessee. The lichen occurs only in frequent fog, or in deep river gorges. Because of its specialized habitat requirements and heavy collection for scientific purposes, the lichen has been listed as an endangered species since January 18, 1995. It is only one of two lichens on the endangered species list, the other being the Florida perforate cladonia. [4]

Description

Genus Cetradonia features a thallus that is enduring and well-formed, typically aggregating into clumps. These thalli are characterized by their almost cylindrical base stalks that evolve into linear, flattened, and strap-like lobes . These lobes are somewhat upright, ranging from unbranched to minimally branched, and have a cartilaginous texture. They measure between 5 and 25 mm (0.2 and 1.0 in) in length and 0.5 to 1 mm in width, often connecting at the base through horizontal structures known as rhizomorphs. The upper surface of the thallus is densely covered by a cortex, with colors from greyish green to pale yellowish brown or olive-green, enclosing a cartilaginous core. In contrast, the lower surface has a thinner cortex, lacks veins , though it may show transverse wrinkling towards the lower end and has furrows and pits near the tips, transitioning in color from white or cream at the tip to black towards the base. [2]

Podetia, which are small stalked structures, emerge predominantly from the upper section of the thallus's lower surface, often near the tip, and have a dirty white hue. These structures can range from 0.3 to 2 mm in height, are covered by a cortex , solid in form, and may or may not contain algae. The reproductive structures, known as ascomata, host clusters of hymenial discs that can expand up to 2 mm across, with individual discs varying from 0.1 to 1 mm in diameter. These discs are flat to spherical in shape and dark brown to black in color, occasionally stacking atop one another in a manner similar to Cladia aggregata . The asci, or spore-bearing structures, are slender, with stalks that can extend up to 2 mm; conidia (asexual spores) have not been observed to occur in this species. [2]

In terms of chemical composition, Cetradonia contains atranorin and lichesterinic acids. [2]

See also

Related Research Articles

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<i>Cladia</i> Genus of lichen-forming fungi

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<i>Pilophorus acicularis</i> Species of fungus

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Cladonia mongkolsukii is a species of fruticose lichen in the family Cladoniaceae. Described as new to science in 2011, it is found in lower-elevation montane scrub forests of northeast Thailand and in Sri Lanka. The specific epithet honors Pachara Mongolsuk, a Thai lichenologist.

<span class="mw-page-title-main">Lichen growth forms</span> Gross morphological classification

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.

<i>Cladonia sobolescens</i> Species of lichen

Cladonia sobolescens, commonly known as the peg lichen, is a species of fruticose lichen. It is found in temperate eastern North America and East Asia.

<i>Cladonia arbuscula</i> Species of cup lichen

Cladonia arbuscula, also referred to as shrubby cup lichen or green reindeer lichen, is a species of cup lichen in the family Cladoniaceae.

<i>Punctelia perreticulata</i> Species of lichen

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.

<i>Pulchrocladia retipora</i> Species of fruticose lichen

Pulchrocladia retipora, commonly known as the coral lichen, is a species of fruticose lichen in the family Cladoniaceae. Found predominantly in Australasia, its habitats range from the Australian Capital Territory to New Zealand's North and South Islands, and even the Pacific region of New Caledonia, where it grows in coastal and alpine heathlands. The lichen features coral-like branches and subbranches with numerous intricate, netlike perforations. It is known by multiple names, with some sources referring to it by its synonym Cladia retipora, or the common name lace lichen.

Cladonia trassii is a species of fruticose lichen in the family Cladoniaceae. It has a circumpolar distribution and is found in arctic/alpine and subarctic habitats.

Hypogymnia pruinoidea is a species of foliose lichen in the family Parmeliaceae. Found in China, it was formally described as a new species in 2012 by Xin-Li Wei and Jiang-Chun Wei. The type specimen was collected from Mt. Taibaishan (Shaanxi) at an elevation of 2,800 m (9,200 ft), where it was found growing on the trunk of Abies. It is only known to occur at this location, a cool and moist montane environment supporting lichen-rich forests and woodlands. The species epithet refers to the pruinose upper thallus surface and lobe tips.

Cladonia longisquama is a species of fruticose lichen in the family Cladoniaceae. It occurs in the Seychelles, where it grows on moss-covered rocks.

Cladonia vescula is a species of fruticose lichen in the family Cladoniaceae. It is known for its small size and unique chemical composition. It can be found in the montane cloud forests and pre-Andean Amazonian forests of Bolivia and Peru, where it grows on mineral soil mixed with humus. This species closely resembles Cladonia peziziformis and Cladonia corymbosula in morphology, but it is more slender and almost entirely lacking a cortex.

Cladonia lutescens is a species of fruticose lichen in the family Cladoniaceae. It occurs in high-altitude conditions of the Himalayas.

Placomaronea kaernefeltii is a rare species of saxicolous (rock-dwelling) lichen in the family Candelariaceae. Found in South America, it was formally described as a new species in 2009 by lichenologists Martin Westberg, Patrik Frödén, and Mats Wedin. The type specimen was collected by the second author from Arica (Chile), between Socoroma and Putre, at an altitude of 3,750 m (12,300 ft), where it was found growing along cracks and pits on a siliceous boulder in a dry mountain slope. The lichen is only known to occur at its type locality, although the authors suggest a wider distribution is likely. The species epithet honours Swedish lichenologist Ingvar Kärnefelt.

Placomaronea minima is a species of saxicolous (rock-dwelling) crustose lichen in the family Candelariaceae. Found in South America and Southern Africa, it was formally described as a new species in 2009 by lichenologists Martin Westberg and Patrik Frödén. The type specimen was collected by the second author from the Santiago Metropolitan Region (Chile) at an altitude of about 1,200 m (3,900 ft), where it was found growing on rocks on a hill outside of San José de Maipo. The species epithet minima refers to its small size.

Cladonia glacialis is a species of fruticose lichen in the family Cladoniaceae. Found in Iceland, it was described as a new species in 2009 by Hördur Kristinsson and Teuvo Ahti. The first author collected the type specimen in 1979 from Arnarfellsmúlar at an elevation of 600 m (2,000 ft). This type locality is on the southeast side of Múlajökull, which is an outlet glacier of the Hofsjökull ice cap. Cladonia glacialis is only known to occur at the type locality. It contains fumarprotocetraric acid as its major lichen product. The authors suggest that the species belongs to the "supergroup" Cladonia, and that it may be closely related to Cladonia phyllophora.

Cladonia monomorpha is a species of terricolous (ground-dwelling), fruticose lichen in the family Cladoniaceae. It is part of the Cladonia pyxidata group, known for brown apothecia on cup-shaped podetia.

Cladonia cayennensis is a species of fruticose lichen in the family Cladoniaceae. It is found in French Guiana, although the authors suggest that its distribution might be more widespread.

Cladonia flavocrispata is a species of fruticose lichen in the family Cladoniaceae. Found in Venezuela and described as a new species in 2013, it is closely related to Cladonia hians, but is distinguished by its unique chemical composition and morphology.

References

  1. "Synonymy: Cetradonia linearis (A. Evans) J.C. Wei & Ahti". Species Fungorum. CAB International. Retrieved July 2, 2015.
  2. 1 2 3 4 Wei, Jiang-Chun; Ahti, Teuvo (2002). "Cetradonia, a new genus in the new family Cetradoniaceae (Lecanorales, Ascomycota)". The Lichenologist. 34 (1): 19–31. doi:10.1006/lich.2001.0354.
  3. Zhou, Qi-Ming; Wei, Jiang-Chun; Ahti, Teuvo; Stenroos, Soili; Högnabba, Filip (2006). "The systematic position of Gymnoderma and Cetradonia based on SSU rDNA sequences". Journal of the Hattori Botanical Laboratory. 100: 871–880.
  4. USFWS. Rock Gnome Lichen. Archived June 14, 2013, at the Wayback Machine Asheville Field Office.