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Atla Alaskana
''Atla alaskana'' is a species of saxicolous (rock-dwelling), crustose lichen in the family Verrucariaceae. Found in Alaska, it was formally described as a new species in 2015 by Sanja and Leif Tibell. The type specimen was collected from Sukakpak Mountain (Brooks Range) at an altitude of ; there, it was found growing on calciferous rock ledges in open dwarf shrub. The lichen has a thick, whitish-grey 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 ... with a granular to verrucose (warted) texture. References Verrucariales Lichen species Lichens described in 2015 Taxa named by Leif Tibell Lichens of Subarctic America {{Eurotiomycetes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saxicolous Lichen
A saxicolous lichen is a lichen that grows on rock. The prefix "sax" from the Latin means "rock" or "stone". Characteristics Saxicolous lichens exhibit very slow growth rates. They may develop on rock substrates for long periods of time, given the absence of external disturbances. The importance of the mineral composition of the rock substrate, as well as the elemental geochemistry Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the ... is also important to the distribution of saxicolous lichens, but the relationship between the substrate influence on lichens, either chemical or textural, is still obscure. Communities of saxicolous lichens are often species-rich in terms of number. References Lichenology {{lichen-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustose Lichen
Crustose lichens are lichens that form a crust which strongly adheres to the substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichens consists of a cortex layer, an algal layer, and a medulla. The upper cortex layer is differentiated and is usually pigmented. The algal layer lies beneath the cortex. The medulla fastens the lichen to the substrate and is made up of fungal hyphae. The surface of crustose lichens is characterized by branching cracks that periodically close in response to climatic variations such as alternate wetting and drying regimes. Subtypes * Powdery – considered as the simplest subtype due to the absence of an organized thallus. :The thallus appears powdery. :E.g. Genera '' Lepraria'', ''Vezdaea'' * Endolithic – grows inside the rock, usually in interstitial spaces between mineral grains. The :upper cortex is usually developed. :E.g. Genus '' Lecidea'' * Epi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verrucariaceae
The Verrucariaceae are a family of mostly lichenised fungi in the order Verrucariales. The lichen-forming species, which comprise the vast majority of the family, have a wide variety of thallus forms, and include crustose (crust-like), foliose (bushy), and squamulose (scaly) representatives. Several characteristics of the spore-bearing structures, the ascomata, define the family, including their perithecioid form–more or less spherical or flask-shaped, with a single opening and otherwise completely enclosed by a wall. Squamulose members of the Verrucariaceae with simple ascospores (lacking partitions called septa), and without algae in the spore-bearing region are known as lichens; there are more than 80 of these species. The family has several dozen lichenicolous (lichen-dwelling) examples, including a few genera that contain solely lichenicolous members. An unusually diverse variety of photobiont partners have been recorded, mostly green algae, but also brown algae and yel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., it borders the Canadian province of British Columbia and the Yukon territory to the east; it also shares a maritime border with the Russian Federation's Chukotka Autonomous Okrug to the west, just across the Bering Strait. To the north are the Chukchi and Beaufort Seas of the Arctic Ocean, while the Pacific Ocean lies to the south and southwest. Alaska is by far the largest U.S. state by area, comprising more total area than the next three largest states ( Texas, California, and Montana) combined. It represents the seventh-largest subnational division in the world. It is the third-least populous and the most sparsely populated state, but by far the continent's most populous territory located mostly north of the 60th paralle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Description
A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have been described previously or are related. In order for species to be validly described, they need to follow guidelines established over time. Zoological naming requires adherence to the ICZN code, plants, the ICN, viruses ICTV, and so on. The species description often contains photographs or other illustrations of type material along with a note on where they are deposited. The publication in which the species is described gives the new species a formal scientific name. Some 1.9 million species have been identified and described, out of some 8.7 million that may actually exist. Millions more have become extinct throughout the existence of life on Earth. Naming process A name of a new species becomes valid (available in zo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type (biology)
In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set (mathematics), set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sukakpak Mountain
Sukakpak Mountain is a prominent 4,459-foot (1,359 meter) mountain summit located in the Philip Smith Mountains of the Brooks Range, in the U.S. state of Alaska. The peak is situated 90 miles north of the Arctic Circle near milepost 203 on the Dalton Highway, and north-northwest of Fairbanks, where the Bettles and Dietrich Rivers merge to form Middle Fork Koyukuk River. The peak's ''Sukakpak'' name was reported in 1930 by the USGS as an Inupiat word, said to mean "marten deadfall." From the north, the mountain resembles a carefully balanced log used to trap marten. The name was officially adopted in 1932 by the U.S. Board on Geographic Names. This famous landmark is notable for its west face, a massive wall of Skajit limestone rising nearly 3,000 feet (900 m) above the surrounding valley. Peculiar ice-cored mounds known as palsas punctuate the ground at the base of the mountain. Sukakpak Mountain was designated in 1990 as a BLM Area of Critical Environmental Concern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brooks Range
The Brooks Range ( Gwich'in: ''Gwazhał'') is a mountain range in far northern North America stretching some from west to east across northern Alaska into Canada's Yukon Territory. Reaching a peak elevation of on Mount Isto, the range is believed to be approximately 126 million years old. In the United States, these mountains are considered a subrange of the Rocky Mountains, whereas in Canada they are considered separate, as the northern border of the Rocky Mountains is considered to be the Liard River far to the south in the province of British Columbia. While the range is mostly uninhabited, the Dalton Highway and Trans-Alaska Pipeline System run through the Atigun Pass (1,415 m, 4,643 ft) on their way to the oil fields at Prudhoe Bay on Alaska's North Slope. The Alaska Native villages of Anaktuvuk and Arctic Village, as well as the very small communities of Coldfoot, Wiseman, Bettles, and Chandalar, are the range's only settlements. In the far west, near th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calciferous
Calciferous sandstone is a geological term relating to strata at the base of the Carboniferous formation, below the entire sequence of coal measures. This term may be unique to the UK. Typically this part of the geological sequence, as in the Touch Hills and Fintry Hills to the west of Stirling tends to contain a mixture of lavas and sedimentary rocks, including sandstone and mudstone, and lies unconformably on top of older Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, w ... strata. Carboniferous geology {{UK-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shrub
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple stems and shorter height, less than tall. Small shrubs, less than 2 m (6.6 ft) tall are sometimes termed as subshrubs. Many botanical groups have species that are shrubs, and others that are trees and herbaceous plants instead. Some definitions state that a shrub is less than and a tree is over 6 m. Others use as the cut-off point for classification. Many species of tree may not reach this mature height because of hostile less than ideal growing conditions, and resemble a shrub-sized plant. However, such species have the potential to grow taller under the ideal growing conditions for that plant. In terms of longevity, most shrubs fit in a class between perennials and trees; some may only last about fiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 were previously known as the thallophytes, a polyphyletic group of distantly related organisms. An organism or structure resembling a thallus is called thalloid, thallodal, thalliform, thalline, or thallose. A thallus usually names the entire body of a multicellular non-moving organism in which there is no organization of the tissues into organs. Even though thalli do not have organized and distinct parts ( leaves, roots, and stems) as do the vascular plants, they may have analogous structures that resemble their vascular "equivalents". The analogous structures have similar function or macroscopic structure, but different microscopic structure; for example, no thallus has vascular tissue. In exceptional cases such as the Lemnoid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verrucariales
Verrucariales is an order (biology), order of Ascomycota, ascomycetous fungi within the subclass Chaetothyriomycetidae of the class Eurotiomycetes. Although most of the Verrucariales are lichenised, the family Sarcopyreniaceae consists of 11 species of lichenicolous fungi, lichenicolous (lichen-dwelling) fungi. Phylogenomics, Phylogenomic analysis suggests that the divergent evolution, divergence between the lichenized Verrucariales and nonlichenized Chaetothyriales occurred about 131 million years ago. Genera of uncertain placement There are some genera in the Verrucariales that have not been placed incertae sedis, with certainty into any family. These are: *''Botryolepraria'' – 2 spp. *''Gemmaspora'' – 1 sp. *''Kalbiana'' – 1 sp. *''Merismatium'' – 10 spp. References Verrucariales, Ascomycota orders Lichen orders Taxa named by David Leslie Hawksworth {{Eurotiomycetes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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