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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'' * Epili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N2 Lichen
N, or n, is the fourteenth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''en'' (pronounced ), plural ''ens''. History One of the most common hieroglyphs, snake, was used in Egyptian writing to stand for a sound like the English , because the Egyptian word for "snake" was ''djet''. It is speculated by many that Semitic people working in Egypt adapted hieroglyphics to create the first alphabet, and that they used the same snake symbol to represent N, because their word for "snake" may have begun with that sound. However, the name for the letter in the Phoenician, Hebrew, Aramaic and Arabic alphabets is ''nun'', which means "fish" in some of these languages. The sound value of the letter was —as in Greek, Etruscan, Latin and modern languages. Use in writing systems represents a dental or alveolar nasal in virtually all languages that use the Latin alp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleopsidium
''Pleopsidium'' is a genus of lichenized fungi in the family Acarosporaceae. The widespread genus, which contains four species, was circumscribed by lichenologist Gustav Wilhelm Körber Gustav Wilhelm Körber (10 January 1817, Hirschberg – 27 January 1885, Breslau) was a German lichenologist. He studied natural sciences in Breslau and Berlin, obtaining his PhD in 1839 with the thesis ''De gonidiis lichenum''. After graduati ... in 1855. References External links * Acarosporales Lecanoromycetes genera Lichen genera Taxa named by Gustav Wilhelm Körber {{Lecanoromycetes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Himalayas
The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 peaks exceeding in elevation lie in the Himalayas. By contrast, the highest peak outside Asia (Aconcagua, in the Andes) is tall. The Himalayas abut or cross five countries: Bhutan, India, Nepal, China, and Pakistan. The sovereignty of the range in the Kashmir region is disputed among India, Pakistan, and China. The Himalayan range is bordered on the northwest by the Karakoram and Hindu Kush ranges, on the north by the Tibetan Plateau, and on the south by the Indo-Gangetic Plain. Some of the world's major rivers, the Indus, the Ganges, and the Tsangpo– Brahmaputra, rise in the vicinity of the Himalayas, and their combined drainage basin is home to some 600 million people; 53 million people live in the Himalayas. The Himalayas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Slave Lake
Great Slave Lake (french: Grand lac des Esclaves), known traditionally as Tıdeè in Tłı̨chǫ Yatıì (Dogrib), Tinde’e in Wıìlıìdeh Yatii / Tetsǫ́t’ıné Yatıé (Dogrib / Chipewyan), Tu Nedhé in Dëne Sųłıné Yatıé (Chipewyan), and Tucho in Dehcho Dene Zhatıé (Slavey), is the second-largest lake in the Northwest Territories of Canada (after Great Bear Lake), the deepest lake in North America at , and the tenth-largest lake in the world by area. It is long and wide. It covers an area of in the southern part of the territory. Its given volume ranges from to and up to making it the 10th or 12th largest by volume. The lake shares its name with the First Nations peoples of the Dene family called Slavey by their enemies the Cree. Towns situated on the lake include (clockwise from east) Łutselk'e, Fort Resolution, Hay River, Hay River Reserve, Behchokǫ̀, Yellowknife, Ndilǫ, and Dettah. The only community in the East Arm is Łutselk'e, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karst
Karst is a topography formed from the dissolution of soluble rocks such as limestone, Dolomite (rock), dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. However, in regions where the dissolved bedrock is covered (perhaps by debris) or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and can be totally missing above ground. The study of ''paleokarst'' (buried karst in the stratigraphic column) is important in petroleum geology because as much as 50% of the world's hydrocarbon reserves are hosted in carbonate rock, and much of this is found in porous karst systems. Etymology The English word ''karst'' was borrowed from German language, German in the late 19th century, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marchantiophyta
The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information. It is estimated that there are about 9000 species of liverworts. Some of the more familiar species grow as a flattened leafless thallus, but most species are leafy with a form very much like a flattened moss. Leafy species can be distinguished from the apparently similar mosses on the basis of a number of features, including their single-celled rhizoids. Leafy liverworts also differ from most (but not all) mosses in that their leaves never have a costa (present in many mosses) and may bear marginal cilia (very rare in mosses). Other differences are not universal for all mosses and liverworts, but the occurrence of leaves arranged in three ranks, the presence of deep lobes or segmented leaves, or a lack of clearly di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epiphyte
An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phorophytes. Epiphytes take part in nutrient cycles and add to both the diversity and biomass of the ecosystem in which they occur, like any other organism. They are an important source of food for many species. Typically, the older parts of a plant will have more epiphytes growing on them. Epiphytes differ from parasites in that they grow on other plants for physical support and do not necessarily affect the host negatively. An organism that grows on another organism that is not a plant may be called an epibiont. Epiphytes are usually found in the temperate zone (e.g., many mosses, liverworts, lichens, and algae) or in the tropics (e.g., many ferns, cacti, orchids, and bromeliads). Epiphyte species make good houseplants due to their minimal wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizocarpon
''Rhizocarpon'' is a genus of crustose, saxicolous (or sometimes lichenicolous), lichens in the family Rhizocarpaceae. The genus is common in arctic-alpine environments, but also occurs throughout temperate, subtropical, and even tropical regions. They are commonly known as map lichens because of the prothallus forming border-like bands between colonies in some species, like the common map lichen ('' Rhizocarpon geographicum''). Taxonomy and phylogeny Together with three small genera (''Catolechia'', ''Poeltinula'' and ''Epilichen''), ''Rhizocarpon'' constitutes the family Rhizocarpaceae. Historically, ca 389 names have been used. However, many species concepts are ill-defined, many names have been synonymized and new species are regularly being described, so true number of species is not entirely clear as of now, but is estimated to be around 200. In molecular work, the genus has also been shown to be paraphyletic, with closely related genera being nested within ''Rhizocarpon' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foliose Lichen
Foliose lichen is one of the morphological classes of lichens, which are complex organisms that arise from the symbiotic relationship between fungi and a photosynthetic partner, typically algae. This partnership allows lichen to live in diverse climates that can range from cold, dry mountains to wet, warm valleys. Lichens develop quite slowly with recorded growth rates of 0.01–27mm/year depending on the species. Their lifespan averages between 30 and 60 years. Lichens have a main body part called the thallus, which is composed of hyphae, and houses the cortex and medulla. The cortex contains the photosynthetic cells while the medulla allows for gas exchange and makes up the bulk of the lichen's thallus. There are three main types of lichens: crustose, foliose, and fruticose. Foliose lichen are characterised by flattened leafy thalli, and an upper and lower cortex. Many have numerous layers, which are stratified, and aid in identifying different types. Foliose lichens at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypothallus
In true slime molds (myxogastria), lichens, and in species of the family Clavicipitaceae, the hypothallus is the layer on which the fruit body sits, lying in contact with the substrate. The word is derived from the Ancient Greek root ''hypó'' ("under") and ''thallós'' ("shoot" or "thallus"). The hypothallus is produced by the plasmodium at the beginning of fructification. Depending on the species, it can be membranous to thick or tender to solid and nearly transparent to brightly coloured. It may surround an individual fruit body, or may form a contiguous connection between multiple fruit bodies. In some rare cases it is missing entirely. In crustose lichens, the hypothallus is the blackish lower layer of the thallus that produces rhizines, which are holdfasts that attach the lichen to its substrate. In some taxa the hypothallus may be involved in the formation of the fruit body. In the "epihypothallic" Stemonitida, the hypothallus forms hollow, tubular stems and a columella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leprose Lichen
Lichens are composite organisms made up of multiple species: a fungal partner, one or more photosynthetic partners, and sometimes a basidiomycete yeast. They are regularly grouped by their external appearance – a characteristic known as their growth form. Lichenologists have described a dozen of these forms: areolate, byssoid, calicioid, cladoniform, crustose, filamentous, foliose, fruticose, gelatinous, leprose, placoidioid and squamulose. Of these, crustose, foliose and fruticose are the most commonly encountered. With the exception of calicioid lichens, growth forms are based on the appearance of the thallus, which is the vegetative (non-reproductive) part of the lichen. In most species, this form is determined by the lichen's fungal partner, though in a small number, it is instead the photobiont that determines the lichen's morphology. In some growth forms, the outermost layer of the thallus consists of tightly woven fungal . This layer, known as the cortex, may be foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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