Ochrolechia gowardii

Last updated

Ochrolechia gowardii
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Pertusariales
Family: Ochrolechiaceae
Genus: Ochrolechia
Species:
O. gowardii
Binomial name
Ochrolechia gowardii
Brodo (1991)

Ochrolechia gowardii is a species of corticolous (bark-dwelling), crustose lichen in the family Ochrolechiaceae. First described in 1991 by the Canadian lichenologist Irwin M. Brodo, this lichen is characterised by its very thin, yellowish-white body (thallus) that partially embeds into tree bark. O. gowardii has small, powdery structures (soralia) that produce asexual reproductive granules, and its disc -like fruiting bodies (apothecia) with pale yellow-orange to light orange centres. O. gowardii can be found in parts of northwestern North America and Scandinavia, typically growing on subalpine fir or Norway spruce trees.

Contents

Taxonomy

The species was formally described as new to science in 1991 by the lichenologist Irwin M. Brodo, as part of a study on the bark-dwelling (corticolous) Ochrolechia species of northern North America. The holotype was collected in Wells Gray Provincial Park in British Columbia, Canada, where it was found growing on Rocky Mountain fir ( Abies lasiocarpa ). The species epithet honours Trevor Goward, a Canadian lichenologist who collected the type specimen in 1980. [1]

Ochrolechia gowardii is a member of the species complex around Ochrolechia parella , a group of similar species with a yellowish-white thallus. [2]

Description

The thallus, or body, of Ochrolechia gowardii is very thin and membranous, with a yellowish-white colour. It is partially embedded in the bark ( endophloedal ) and features scattered, irregularly shaped soralia—structures that produce powdery asexual reproductive granules (soredia). These soralia break through the thallus, creating ragged margins, and measure between 0.5 and 1.0 mm in diameter. The soredia themselves are coarsely granular and yellowish-white in colour. Unlike some other lichens, O. gowardii has a distinct margin but lacks a prothallus, a preliminary growth feature that some lichens exhibit. [1]

The apothecia (fruiting bodies) of O. gowardii are commonly present and are sessile , meaning they sit directly on the thallus without a stalk. They are small, ranging from 0.6 to 1.0 mm in diameter, but can occasionally reach up to 1.5 mm. The discs of the apothecia are pale yellow-orange to yellowish-pink or light orange and are usually coated with a coarse, powdery substance ( pruina ), especially when young. The margins of the apothecia are smooth and even, and they remain level with the disc in mature specimens. [1]

The pictured Ochrolechia androgyna, common in Europe, is a possible lookalike. Ochrolechia androgyna Ti C'Hazh Kozh.jpg
The pictured Ochrolechia androgyna , common in Europe, is a possible lookalike.

The internal structure of the apothecia reveals a hymenium (the spore-producing layer) that is 230–250  μm tall. The hypothecium , a thin layer beneath the hymenium, is about 10 μm thick, while the subhymenium , located just above the hypothecium, is loose and sparse, measuring around 25 μm thick. The excipulum proprium , a thin layer surrounding the hymenium, extends to the surface of the disc and is about 10 μm thick. The amphithecium , a layer surrounding the entire apothecium, is also thin and filled with small, angular crystals, especially at its base. The cortex, or outer layer, is uniform, thin, and non-gelatinous, with a thickness of about 25 μm. The algal layer is mainly concentrated at the lateral margins and features clumps of algae beneath the hypothecium. The ascospores , which are the sexual reproductive spores, are relatively large, measuring 45–65 μm by 22–33 μm, and are consistently found in groups of four per ascus. [1]

Ochrolechia gowardii is distinguished from similar species, such as O. trochophora , by its unique chemical reactions and thin, membranous thallus. The species is also notable for the presence of C+ (red) soredia, a characteristic not found in any other Ochrolechia species. The similarity of its habitat with that of the rare lichen Toensbergia leucococca suggests a shared ecological niche. [1] A possible lookalike in Europe is Ochrolechia androgyna , which usually has a thicker thallus and more delimited soralia. [2] Additionally, this species has eight spores per ascus compared to four in O. gowardii. [3]

Chemistry

The thallus of Ochrolechia gowardii does not react to common lichen spot tests (C−, KC−, K−, PD−), but the soralia react positively to C+ (red) and KC+ (red) tests, indicating the presence of gyrophoric and lecanoric acids. The apothecial margin, cortex, and medulla do not show reactions to these tests, but the apothecial disc does react positively to C+ (red), KC+ (red), and KOH+ (yellow) tests. The apothecia also contain variolaric acid, which is a distinguishing chemical characteristic of this species. [1]

Habitat and distribution

This lichen is typically found in subalpine forests, growing on the bark of Abies lasiocarpa (subalpine fir) at elevations between 1,300 and 1,650 m (4,270 and 5,410 ft). Ochrolechia gowardii has been recorded in several locations within the northern Rocky Mountains, including British Columbia and Alberta in Canada, and parts of Idaho and Montana in the United States. [1] The known northernly extent of its North American distribution was extended when it was reported from Alaska. [4] It has also been recorded in Sør-Trøndelag and Nordland in Norway, [2] Central Norway, [5] and in the province of Jämtland in Sweden; in both countries the lichen was found growing on Picea abies . [3]

Related Research Articles

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

Ochrolechia is a genus of crustose lichens in the family Ochrolechiaceae. These lichens typically form uneven, often thick, crust-like growths on various surfaces and are characterised by their white to pale grey thalli, which may have a greenish tint. The genus has a long evolutionary history, with fossils dating back to the Paleogene period, about 34 million years ago. Ochrolechia species have disc-like apothecia, which are usually yellowish or brownish-pink and often covered with a fine white powdery coating. The genus is widely distributed and includes both common and rare species, with some found in extreme environments such as arctic and alpine regions. Ochrolechia lichens produce diverse secondary metabolites, including orcinol depsides, depsidones, and xanthones.

Graphis marusae is a species of corticolous (bark-dwelling) crustose lichen in the family Graphidaceae. It is found in a relict tropical lowland rainforest in Veracruz, Mexico, growing in exposed understory.

<i>Ochrolechia africana</i> Species of lichen

Ochrolechia africana, commonly known as the frosty saucer lichen, is a species of crustose and corticolous (bark-dwelling) lichen in the family Ochrolechiaceae. It is a widely distributed species, found in tropical and subtropical areas of southern Africa, Asia, Australia, North America, and South America. The lichen is characterized by the presence of a white "frosty" or powdery apothecia.

Maronora is a monotypic fungal genus in the family Fuscideaceae. It contains the single species Maronora cyanosora, a corticolous (bark-dwelling) lichen. It is characterised by its distinctive bluish-grey circular soralia on the thallus, Lecanora-like apothecia, and simple, hyaline ascospores.

Cratiria sorediata is a species of corticolous (bark-dwelling), crustose lichen in the family Caliciaceae. It was first described as a new species in 2009. The type specimen was collected from Aldabra in the Seychelles.

Caloplaca sterilis is a corticolous (bark-dwelling), crustose lichen belonging to the family Teloschistaceae, described in 2011. It is primarily found in steppe and sand dune habitats in the Black Sea region, and has been recorded from Bulgaria, Romania, southwest Russia, and Ukraine. Caloplaca sterilis is characterised by tiny squamules/areoles with contrasting pale greyish-green to greenish soredia. It is easily overlooked and challenging to identify when completely sorediate and sterile, especially as its soredia do not contain the typical Sedifolia-grey pigment.

Megalospora austropacifica is a species of corticolous (bark-dwelling), crustose lichen in the family Megalosporaceae. It is found on the islands of Taveuni and Viti Levu in Fiji. It has a yellowish grey to whitish grey, glossy thallus that is thick and may appear slightly wrinkled or smooth, often with irregular cracks and small papillae containing conidiomata, but lacking isidia and soredia. Its apothecia are circular, up to 4.5 mm in diameter, with the disc evolving from concave to slightly convex and coloured from orange-brown to red-brown, surrounded by a thick, prominent margin.

Malmidea cineracea is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Nicaragua.

Rinodina maronisidiata is a species of corticolous (bark-dwelling), crustose lichen in the family Physciaceae, first described in 2018. Found at high altitudes in the Venezuelan Andes, it is characterised by its unique isidia-covered thallus and specific ascospore morphology.

Malmidea albomarginata is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela.

Malmidea allopapillosa is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela.

Malmidea hernandeziana is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela. The distinctive features of this species include a thallus with coralloid-like outgrowths, light-coloured fruiting bodies (ascomata) with a specialised structural layer, relatively large spores that tend to have slightly thickened walls at their ends, and the absence of specific lichen products typically found in other species of the genus. This combination of characteristics sets Malmidea hernandeziana apart from other species in the genus Malmidea.

Malmidea leucopiperis is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Brazil.

Malmidea subcinerea is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela. The lichen has a smooth, dull thallus varying in colour from grey to olive, with a white internal medulla. It has sessile, rounded apothecia with light beige to greyish-brown discs.

Byssoloma xanthonicum is a species of corticolous (bark-dwelling), crustose lichen in the family Pilocarpaceae. It is found in New Caledonia.

Fellhanera ivoriensis is a species of foliicolous (leaf-dwelling) lichen. First described in 2001, this species is distinguished from its relatives in the Fellhanera by its soredia-covered thallus and the characteristics of its apothecia. It is native to the Ivory Coast in West Africa.

Biatora toensbergii is a species of corticolous (bark-dwelling), crustose lichen in the family Ramalinaceae. It is found in Norway and northwestern North America.

Lecidea toensbergii is a species of saxicolous (rock-dwelling), crustose lichen in the family Lecideaceae. Described as a new species in 2018, it has been documented from several locations in Norway and a single location in Sweden, where it grows in rocky alpine environments.

Ramboldia gowardiana is a species of corticolous (bark-dwelling), crustose lichen in the family Ramboldiaceae. First discovered in 2003 in Montana, United States, it typically appears as a grayish or greenish crust on tree bark, particularly on conifers like pines and firs. The lichen is characterised by its small, bright red to orange-red reproductive structures (apothecia) visible on its surface. R. gowardiana is found in dry, temperate forests from Alaska to California, often at elevations between 300 and 1,400 meters. Initially classified in a different genus, it was reclassified as Ramboldia in 2008 based on genetic studies. This lichen is part of the biodiversity of the Pacific Northwest region of North America.

Meridianelia is a fungal genus in the family Elixiaceae. It consists of the single species Meridianelia maccarthyana, a corticolous (bark-dwelling), crustose lichen. This lichen forms greyish-white, crust-like growths on tree bark in subalpine woodlands of Tasmania, Australia. Discovered in 2003 and scientifically described in 2009, Meridianelia is classified in the small fungal family Elixiaceae based on its genetic and structural characteristics. The genus is notable for its unique reproductive structures and its apparent rarity, having been found in only a few locations despite growing in a relatively common type of forest.

References

  1. 1 2 3 4 5 6 7 Brodo, Irwin M. (1991). "Studies in the lichen genus Ochrolechia. 2. Corticolous species of North America". Canadian Journal of Botany. 69 (4): 733–772. doi:10.1139/b91-099.
  2. 1 2 3 Holien, Håkon (1992). "Some lichen species new to Norway and Sweden" (PDF). Graphis Scripta. 4: 69–72.
  3. 1 2 Jonsson, Fredrik (2002). "Ochrolechia gowardii new to Sweden" (PDF). Graphis Scripta. 13: 58.
  4. ↑ McCune, B.; Arup, U.; Breuss, O.; Meglio, E.; Di Meglio, J.; Esslinger, T.L; Magain, N.; Miadlikowska, J.; Miller, A.E.; Muggia, L.; Nelson, P.R.; Rosentreter, R.; Schultz, M.; Sheard, J.W.; Tønsberg, T.; Walton, J. (2018). "Biodiversity and ecology of lichens of Katmai and Lake Clark National Parks and Preserves, Alaska" (PDF). Mycosphere. 9 (4): 859–930. doi:10.5943/mycosphere/9/4/10.
  5. ↑ Holien, Håkon (1996). "The lichen flora on Picea abies in a suboceanic spruce forest area in Central Nowray with emphasis on the relationship to site and stand parameters". Nordic Journal of Botany. 17 (1): 55–76. doi:10.1111/j.1756-1051.1997.tb00290.x.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.