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Emodomelanelia
''Emodomelanelia'' is a lichen genus in the family Parmeliaceae. It is monotypic, containing the single foliose Himalayan species ''Emodomelanelia masonii''. Taxonomy ''Emodomelanelia masonii'' was first described in 1991 as ''Parmelia masonii'' by lichenologists Theodore Esslinger and Josef Poelt. It was named in honour of Mason Hale, the "preeminent student of the Parmeliaceae". The genus was circumscribed in 2010 by Pradeep Kumar Divakar and Ana Crespo. ''Emodomelanelia'' is in the "Melanohalea" clade (one of nine major groups in the Parmelioid clade of the Parmeliaceae) along with the genera '' Melanelixia'' and ''Melanohalea''. The genus name combines ''emodo'' (referring to the Himalayas) and ''melanelia'' (referring to the brown colour of the upper thallus surface). Description Characteristics of the genus ''Emodomelanelia'' include an olive brown to brown thallus, narrow to moderately broad lobes, a non-pored epicortex, the presence of effigurate pseudocyphellae (i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanohalea
''Melanohalea'' is a genus of foliose lichens in the family Parmeliaceae. It contains 30 mostly Northern Hemisphere species that grow on bark or on wood. The genus is characterized by the presence of pseudocyphellae, usually on warts or on the tips of isidia, a non-pored and a medulla containing depsidones or lacking secondary compounds. ''Melanohalea'' was circumscribed in 2004 as a segregate of the morphologically similar genus ''Melanelia''. Taxonomy ''Melanohalea'' was circumscribed in 2004 by lichenologists Oscar Blanco, Ana Crespo, Pradeep K. Divakar, Theodore Esslinger, David L. Hawksworth and H. Thorsten Lumbsch. It is a segregate of ''Melanelia'', a genus created in 1978 to contain the brown '' Parmelia'' species. The circumscription of this genus was questioned later, especially after early molecular phylogenetics studies demonstrated that it was not monophyletic. Subsequently, two genera, '' Melanelixia'' and ''Melanohalea'', were created. ''Melanohalea'' or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parmeliaceae
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'' ( 822 species), '' Usnea'' (355 species), ''Parmotrema'' ( 255 species), and '' Hypotrachyna'' (262 species). Nearly all members of the family have a symbiotic association with a green alga (most often '' Trebouxia'' spp., but '' Asterochloris'' spp. are known to associate with some species).Miadlikowska, J. ''et al.'' (2006). New insights into classification and evolution of the Lecanoromycetes (Pezizomycotina, Ascomycota) from phylogenetic analyses of three ribosomal RNA- and two protein-coding genes. ''Mycologia'' 98: 1088-1103. http://www.mycologia.org/cgi/reprint/98/6/1088.pdf The majority of Parmeliaceae species have a foliose, fruticose, or subfruticose growth form. The morphological diversity and complexity exhibited by this group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conidia
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the way they are generated through the cellular process of mitosis. The two new haploid cells are genetically identical to the haploid parent, and can develop into new organisms if conditions are favorable, and serve in biological dispersal. Asexual reproduction in ascomycetes (the phylum Ascomycota) is by the formation of conidia, which are borne on specialized stalks called conidiophores. The morphology of these specialized conidiophores is often distinctive between species and, before the development of molecular techniques at the end of the 20th century, was widely used for identification of (''e.g.'' '' Metarhizium'') species. The terms microconidia and macroconidia are sometimes used. Conidiogenesis There are two main types of coni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichen Genera
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not plants. They may have tiny, leafless branches ( fruticose); flat leaf-like structures ( foliose); grow crust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Lecanorales Genera
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa. Examples Just as the term ''monotypic'' is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within a family. Some examples of monotypic groups are: Plants * In the order Amborellales, there is only one family, Amborellaceae and there is only one genus, ''Amborella'', and in this genus there is only one species, namely ''Amborella trichopoda.'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subalpine
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial factor in shaping plant community, biodiversity, metabolic processes and ecosystem dynamics for montane ecosystems. Dense montane forests are common at moderate elevations, due to moderate temperatures and high rainfall. At higher elevations, the climate is harsher, with lower temperatures and higher winds, preventing the growth of trees and causing the plant community to transition to montane grasslands, shrublands or alpine tundra. Due to the unique climate conditions of montane ecosystems, they contain increased numbers of endemic species. Montane ecosystems also exhibit variation in ecosystem services, which include carbon storage and water supply. Life zones As elevation increases, the climate becomes cooler, due to a decrease in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpine Plant
Alpine plants are plants that grow in an alpine climate, which occurs at high elevation and above the tree line. There are many different plant species and taxa that grow as a plant community in these alpine tundra. These include perennial grasses, sedges, forbs, cushion plants, mosses, and lichens.. Alpine plants are adapted to the harsh conditions of the alpine environment, which include low temperatures, dryness, ultraviolet radiation, wind, drought, poor nutritional soil, and a short growing season. Some alpine plants serve as medicinal plants. Ecology Alpine plants occur in a tundra: a type of natural region or biome that does not contain trees. Alpine tundra occurs in mountains worldwide. It transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as ''Krummholz''. With increasing elevation, it ends at the snow line where snow and ice persist through summer, also known as the Nival Zone. Alpine plants are ... [...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] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example ''Cytisus aeolicus'' is an endemite of the Italian flora. ''Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitric Acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% , it is referred to as ''fuming nitric acid''. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. Nitric acid is also commonly used as a strong oxidizi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cortex (botany)
In botany, a cortex is an outer layer of a stem or root in a vascular plant, lying below the epidermis but outside of the vascular bundles. The cortex is composed mostly of large thin-walled parenchyma cells of the ground tissue system and shows little to no structural differentiation. The outer cortical cells often acquire irregularly thickened cell walls, and are called collenchyma cells. Plants Stems and branches In the three dimensional structure of herbaceous stems, the epidermis, cortex and vascular cambium form concentric cylinders around the inner cylindrical core of pith. Some of the outer cortical cells may contain chloroplasts, giving them a green color. They can therefore produce simple carbohydrates through photosynthesis. In woody plants, the cortex is located between the periderm (bark) and the vascular tissue (phloem, in particular). It is responsible for the transportation of materials into the central cylinder of the root through diffusion and may al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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