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Melanelixia
''Melanelixia'' is a genus of foliose lichens in the family Parmeliaceae. It contains 15 Northern Hemisphere species that grow on bark or on wood. The genus is characterized by a pored or fenestrate epicortex (a thin homogeneous polysaccharide layer on the surface of the cortex), and the production of lecanoric acid as the primary chemical constituent of the medulla. ''Melanelixia'' was circumscribed in 2004 as a segregate of the related genus ''Melanelia''. Taxonomy ''Melanelixia'' was circumscribed in 2004 as a segregate of the genus ''Melanelia''. ''Melanelixia'' originally contained eight species, including the type, '' M. glabra''. The genus name combines ''Melanelia'' with the name of lichenologist John A. Elix, "for his immense contributions to lichen systematics and chemistry, especially in Parmeliaceae." Several species distributed in the Southern Hemisphere were removed from ''Melanelixia'' and transferred to the new genus '' Austromelanelixia'' in 2017. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanelixia Glabra
''Melanelixia'' is a genus of foliose lichens in the family Parmeliaceae. It contains 15 Northern Hemisphere species that grow on bark or on wood. The genus is characterized by a pored or fenestrate epicortex (a thin homogeneous polysaccharide layer on the surface of the cortex), and the production of lecanoric acid as the primary chemical constituent of the medulla. ''Melanelixia'' was circumscribed in 2004 as a segregate of the related genus ''Melanelia''. Taxonomy ''Melanelixia'' was circumscribed in 2004 as a segregate of the genus ''Melanelia''. ''Melanelixia'' originally contained eight species, including the type, '' M. glabra''. The genus name combines ''Melanelia'' with the name of lichenologist John A. Elix, "for his immense contributions to lichen systematics and chemistry, especially in Parmeliaceae." Several species distributed in the Southern Hemisphere were removed from ''Melanelixia'' and transferred to the new genus '' Austromelanelixia'' in 2017. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanelixia Fuliginosa PR4 (1)
''Melanelixia'' is a genus of foliose lichens in the family Parmeliaceae. It contains 15 Northern Hemisphere species that grow on bark or on wood. The genus is characterized by a pored or fenestrate epicortex (a thin homogeneous polysaccharide layer on the surface of the cortex), and the production of lecanoric acid as the primary chemical constituent of the medulla. ''Melanelixia'' was circumscribed in 2004 as a segregate of the related genus ''Melanelia''. Taxonomy ''Melanelixia'' was circumscribed in 2004 as a segregate of the genus ''Melanelia''. ''Melanelixia'' originally contained eight species, including the type, '' M. glabra''. The genus name combines ''Melanelia'' with the name of lichenologist John A. Elix, "for his immense contributions to lichen systematics and chemistry, especially in Parmeliaceae." Several species distributed in the Southern Hemisphere were removed from ''Melanelixia'' and transferred to the new genus '' Austromelanelixia'' in 2017. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austromelanelixia
''Austromelanelixia'' is a genus of five species of foliose lichens in the family Parmeliaceae. All species are found in the Southern Hemisphere. Taxonomy The genus was circumscribed in 2017 to accommodate a clade of Southern Hemisphere species formerly placed in genus ''Melanelixia''. Although they were not included in the original circumscription of ''Melanelixia'', they were later added by virtue of their sister-group relationship to other ''Melanelixia'' species. ''Austromelanelixia'' appears to have been accepted as a valid genus by later lichenologists and has been included in recent updates of fungal classification. Description ''Austromelanelixia'' species have a foliose thallus with an upper surface that ranges in colour from olive-green to dark brown. There is often hyaline cortical hairs on lobe apices or isidial tip, and it is spotted or stained (maculate) particularly on the margins of the lobes. Pseudocyphellae are not present. The upper cortex is covered by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanelixia Ahtii
''Melanelixia ahtii'' is a species of foliose lichen in the family Parmeliaceae. Found in the United States, it was formally described as a new species in 2016 by Theodore Lee Esslinger, Ana Crespo, Helge Thorsten Lumbsch, Pradeep Kumar Divakar, and Steven Leavitt. The type specimen was collected from the north side of the Columbia River Gorge ( Klickitat County, Washington). Here, at an altitude of above sea level, it was found in a mixed oak- ponderosa pine forest, growing as an epiphyte on an oak. The species is known from DNA-verified collections in four western US states: California, Idaho, Oregon, and Washington. The species epithet ''ahtii'' honours Finnish lichenologist Teuvo Ahti Teuvo ("Ted") Tapio Ahti (born 1934) is a Finnish botanist and lichenologist. He has had a long career at the University of Helsinki that started in 1963, and then following his retirement in 1997, at the Botanical Museum of the Finnish Museum ..., "for his contributions to unde ... [...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 is en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Glucan
α-Glucans (alpha-glucans) are polysaccharides of D-glucose monomers linked with glycosidic bonds of the alpha form. α-Glucans use cofactors in a cofactor site in order to activate a glucan phosphorylase enzyme. This enzyme causes a reaction that transfers a glucosyl portion between orthophosphate and α-I,4-glucan. The position of the cofactors to the active sites on the enzyme are critical to the overall reaction rate thus, any alteration to the cofactor site leads to the disruption of the glucan binding site. Alpha-glucan is also commonly found in bacteria, yeasts, plants, and insects. Whereas the main pathway of α-glucan synthesis is via glycosidic bonds of glucose monomers, α-glucan can be comparably synthesized via the maltosyl transferase GlgE and branching enzyme GlgB. This alternative pathway is common in many bacteria, which use GlgB and GlgE or the GlgE pathway exclusively for the biosynthesis of α-glucan. The GlgE pathway is especially prominent in actinomycetes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), 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 taxonomy (biology), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depsidone
Depsidones (+ "depside" + "one") are chemical compounds that are sometimes found as secondary metabolites in lichens. They are esters that are both depsides and cyclic ethers. An example is norstictic acid Norstictic acid is a depsidone produced as a secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fun .... References {{reflist Biochemistry Carboxylate esters ... [...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 oxidizing agen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium
Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, that is easily removed to create an ion with a positive charge – a cation, that combines with anions to form salts. Potassium in nature occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac- colored flame. It is found dissolved in sea water (which is 0.04% potassium by weight), and occurs in many minerals such as orthoclase, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Pigment
Biological pigments, also known simply as pigments or biochromes, are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, feathers, fur and hair contain pigments such as melanin in specialized cells called chromatophores. In some species, pigments accrue over very long periods during an individual's lifespan. Pigment color differs from structural color in that it is the same for all viewing angles, whereas structural color is the result of selective reflection or iridescence, usually because of multilayer structures. For example, butterfly wings typically contain structural color, although many butterflies have cells that contain pigment as well. Biological pigments See conjugated systems for electron bond chemistry that causes these molecules to have pigment. * Heme/porphyrin-based: chlorophyll, bilirubin, hemocy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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