Psiloparmelia

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Psiloparmelia
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Lecanorales
Family: Parmeliaceae
Genus: Psiloparmelia
Hale (1989)
Type species
Psiloparmelia distincta
(Nyl.) Hale (1989)

Psiloparmelia is a genus of lichen belonging to the family Parmeliaceae. It contains 13 Southern Hemisphere species, most of which are found growing on rocks at high elevations in South America. There are several characteristic features of the genus that are used to distinguish it from the morphologically similar genera, such as Arctoparmelia , Flavoparmelia , and Xanthoparmelia . These include a dark, velvety lower thallus surface that usually lacks rhizines, a negative test for lichenan, and a high concentration of usnic acid and atranorin in the cortex.

Contents

Taxonomy

Psiloparmelia was circumscribed by Mason Hale in 1989 with two species: Psiloparmelia arhizinosa , and the type species, Psiloparmelia distincta . Hale had previously placed this taxon (as Parmelia distincta) in the genus Xanthoparmelia . He also considered placement in Arctoparmelia due to similarities in lobe configuration, cortical chemistry, and the presence of a velvety lower surface. However, other differing characteristics precluded this classification, including a complete lack of rhizines and the presence of isolichenan in the cell walls. Hales' subsequent discovery of a species similar to P. distincta in Lesotho convinced him that these two species were sufficiently distinct from both Arctoparmelia and Xanthoparmelia to warrant the creation of a new genus, Psiloparmelia, to contain them. Some taxonomic inspiration was drawn from Vilmos Gyelnik's Parmelia sect. Xanthoparmelia subsect. Endocoerulea, which he created in 1931; [1] it was in this subsection that Parmelia distincta was originally classified. [2] Scanning electron microscopy was used in a 1992 study to evaluate the structure of the epicortex in Psiloparmelia, revealing the presence of a rudimentary pored epicortex, which established another character of the genus. [3]

Nine newly described species and one new combination were added to the genus in 1992 by John Elix and Tom Nash, who published a synopsis of the genus. [4] In 2006, molecular data supported the transfer of Xanthoparmelia peruviensis to Psiloparmelia, despite it not sharing all the morphological features characteristic of other species in the genus, particularly in having a densely rhizinate lower surface. [5]

Description

Psiloparmelia species are foliose lichens growing on rocks, to which they can be tightly or loosely attached, depending on the species. The thallus, which reaches a diameter of 3–14 cm (1.2–5.5 in), is made of irregularly shaped lobes whose margins lack cilia. [4] The upper cortex of Psiloparmelia is a palisade plectenchyma – comprising hyphae arranged perpendicular to the surface. It is partly covered by a rudimentary epicortex (a thin homogeneous polysaccharide layer on the surface of the cortex) with pores. [3] The texture of the upper cortex ranges from smooth to wrinkled, and it is pruinose. Pustules and soredia may be present or absent, depending on the species, while pseudocyphellae and isidia are always absent. The cell walls contain the alpha glucan molecule isolichenan. Green algae are the photobiont partner in Psiloparmelia. [4]

The lower surface of the thallus is black and velvety. It is covered with tiny bumps (minutely papillate), and usually lacks rhizines. Most species have an even finer velvety zone around the margin that is yellowish-grey or mouse-grey. The apothecia are either attached directly to the thallus surface (adnate), or are mounted on a small stalk (substipitate); they measure 2–5 mm in diameter. The ascospores, which number eight per ascus, have a spherical to elliptical shape, and measure 9–12 by 5–9  μm. [4]

Psiloparmelia has a relatively diverse secondary chemistry. Metabolites that have been recorded from the genus include usnic acid, atranorin, and the following β-orcinol derivatives: constipatic acid, protoconstipatic acid, diffractiac acid, fumarprotocetraric acid, hypostictic acid, 4-O-methylhypoprotocetraric acid, isousnic acid, norstictic acid, and salazinic acid. There are several other lichen acids that are found in trace amounts. The presence of these lichens compounds helps to distinguish between morphologically similar species in the genus. [4]

Habitat and distribution

Psiloparmelia is a genus of saxicolous lichens, although Psiloparmelia distincta was recently recorded growing on old bones, the first reported time on that substrate. [6] The genus has a Southern Hemisphere distribution, with most of the species located in South America. Twelve of the thirteen species in the genus are found in high altitudes on the Andes Mountains, ranging from Ecuador and Peru south to Bolivia and northern Argentina. They are typically the most common saxicolous foliose lichens that are collected in these locales. Psiloparmelia arhizinosa is the only species to break this distributional pattern; it is found at alpine habitats at high elevations 3,000–3,300 ft (910–1,010 m) in Lesotho. [4]

Species

Related Research Articles

<i>Parmelia</i> (fungus) Genus of lichens

Parmelia is a genus of medium to large foliose lichens. It has a global distribution, extending from the Arctic to the Antarctic continent but concentrated in temperate regions. There are about 40 species in Parmelia. In recent decades, the once large genus Parmelia has been divided into a number of smaller genera according to thallus morphology and phylogenetic relatedness.

<span class="mw-page-title-main">Parmeliaceae</span> Family of lichens

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.

<i>Myelochroa</i> Genus of lichens

Myelochroa is a genus of foliose lichens in the family Parmeliaceae. They are commonly known as axil-bristle lichens. It was created in 1987 to contain species formerly placed in genus Parmelina that had a yellow-orange medulla due to the presence of secalonic acids. Characteristics of the genus include tightly attached thalli with narrow lobes, cilia on the axils, and a rhizinate black lower surface. Chemical characteristics are the production of zeorin and related triterpenoids in the medulla. Myelochroa contains about 30 species, most of which grow on bark. The genus has centres of distribution in Asia and North America.

<i>Flavoparmelia</i> Genus of fungi

Flavoparmelia is a genus of foliose lichens in the family Parmeliaceae. Because of their appearance, they are commonly known as greenshield lichens. The widely distributed genus contains 32 species. It was circumscribed by American lichenologist Mason Hale in 1986 to contain 17 former Pseudoparmelia species with broad lobes, usnic acid in the cortex, and isolichenan in the cell walls.

<i>Canoparmelia</i> Genus of lichens

Canoparmelia is a genus of lichen-forming fungi in the family Parmeliaceae. The widespread genus contains about 35 species. Canoparmelia, a segregate of the parmelioid lichen genus Pseudoparmelia, was circumscribed by John Elix and Mason Hale in 1986.

<i>Punctelia</i> Genus of foliose lichens

Punctelia is a genus of foliose lichens belonging to the large family Parmeliaceae. The genus, which contains about 50 species, was segregated from genus Parmelia in 1982. Characteristics that define Punctelia include the presence of hook-like to thread-like conidia, simple rhizines, and point-like pseudocyphellae. It is this last feature that is alluded to in the vernacular names speckled shield lichens or speckleback lichens.

<i>Xanthoparmelia</i> Genus of fungi

Xanthoparmelia is a genus of foliose lichen in the family Parmeliaceae. Xanthoparmelia is synonymous with Almbornia, Neofuscelia, Chondropsis, Namakwa, Paraparmelia, and Xanthomaculina. This genus of lichen is commonly found in the United States, as well as Australia, New Zealand and Ecuador.

<i>Xanthoparmelia mougeotii</i> Species of foliose lichen

Xanthoparmelia mougeotii is a species of foliose lichen belonging to the family Parmeliaceae.

<i>Xanthoparmelia conspersa</i> Species of foliose lichen in the family Parmeliaceae

Xanthoparmelia conspersa, commonly known as the peppered rock-shield, is a foliose lichen and the type species of genus Xanthoparmelia. It is widely distributed in temperate zones, and has been recorded from Japan, Europe, Africa, North America, and South America.

<i>Xanthoparmelia mexicana</i> Species of foliose lichen

Xanthoparmelia mexicana, commonly known as the salted rock-shield, is a foliose lichen in the family Parmeliaceae. It grows in 4–10 cm diameter rosettes of gray-green to yellow-green lobes in arid climates all over the world.

Arctoparmelia separata, commonly known as the rippled ring lichen, is a species of foliose, ring lichen in the family Parmeliaceae with a roughly circumpolar distribution.

<i>Xanthoparmelia lineola</i> Species of foliose lichen

Xanthoparmelia lineola, commonly known as the tight rock-shield, is a foliose lichen species in the genus Xanthoparmelia. It is a common species with a temperate distribution. Found in North America and South Africa, it grows on rocks.

Bulbothrix meizospora is a species of foliose lichen in the family Parmeliaceae. It is found in Africa, Asia, and South America, where it grows on tree bark.

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

Punctelia punctilla is a species of foliose lichen in the family Parmeliaceae. It is found in Africa, South America, and North America, where it grows on bark and on rocks. The main characteristics that distinguish Punctelia punctilla from other species of Punctelia are the presence of isidia on the thallus surface, a pale brown thallus undersurface, and the presence of lecanoric acid in the medulla.

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

Punctelia graminicola is a species of foliose (leafy) lichen in the family Parmeliaceae. It grows on rocks, and, less frequently, on bark in North America, South America, and East Africa. It has a blue-grey thallus measuring up to about 15 cm (6 in), covered with tiny pores called pseudocyphellae. Sometimes the lichen forms small lobes that project out from the surface. Fruiting bodies are uncommon in this species; if present, they resemble small cups with a brown internal disc measuring 3–10 mm (0.1–0.4 in) in diameter. A lookalike species, Punctelia hypoleucites, is not readily distinguishable from Punctelia graminicola by appearance or habitat alone; these species can only be reliably differentiated by examining the length of their conidia.

Psiloparmelia salazinica is a species of foliose lichen in the family Parmeliaceae. It is found in South America.

<i>Hypotrachyna osseoalba</i> Species of lichen

Hypotrachyna osseoalba, commonly known as the grainy loop lichen, is a species of foliose lichen in the family Parmeliaceae. It is widely distributed in subtropical and temperate areas of the world. Characteristic features of the lichen include the pustules in its cortex, the somewhat linear shape of the lobes comprising the thallus, and the branched rhizines.

Xanthoparmelia waboomsbergensis is a species of foliose lichen in the family Parmeliaceae. It was formally described as a new species in 2002 by Australian lichenologist John Elix. The type specimen was collected from the summit of Waboomsberg mountain at an altitude of 1,220 m (4,000 ft). The species epithet refers to the type locality, the only place the lichen is known to occur.

Xanthoparmelia callifolioides is a foliose lichen that belongs to the genus Xanthoparmelia.

References

  1. ↑ Gyelnik, V. "Additamenta ad cognitionem Parmeliarum II". Feddes Repertorium Specierum Novarum Regni Vegetabilis. 29: 272–291.
  2. ↑ Hale, Mason (1989). "A new lichen genus, Psiloparmelia Hale (Ascomycotina: Parmeliaceae)". Mycotaxon. 35 (1): 41–44.
  3. 1 2 Lumbsch, H. Thorsten; Schuster, Günter; Elix, John A.; Nash III, Thomas H. (1992). "The epicortical structure of the lichen genus Psiloparmelia (Parmeliaceae : Ascomycotina)". Mycotaxon. 45: 489–494.
  4. 1 2 3 4 5 6 Elix, John A.; Nash, Thomas H. (1992). "A synopsis of the lichen genus Psiloparmelia (Ascomycotina, Parmeliaceae)". The Bryologist. 95 (4): 377–391. doi:10.2307/3243562. JSTOR   3243562.
  5. 1 2 Thell, Arne; Feurerer, Tassilo; Elix, John A.; Kärnefelt, Ingvar (2006). "A contribution to the phylogeny and taxonomy of Xanthoparmelia (Ascomycota, Parmeliaceae)". Journal of the Hattori Botanical Laboratory. 100: 797–807. doi:10.18968/jhbl.100.0_797. Open Access logo PLoS transparent.svg
  6. ↑ García, Renato; Magnin, Lucia; Miotti, Laura; Barrientos, Gustavo (2020). "Lichens growing on human bone remains: A case study from continental Patagonia (Deseado Massif, Santa Cruz, Argentina)". Journal of King Saud University - Science. 32 (3): 2219–2221. doi: 10.1016/j.jksus.2020.02.029 . S2CID   216163263.
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