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Pyxine Pustulata
''Pyxine pustulata'' is a species of corticolous (bark-dwelling), foliose lichen in the family Caliciaceae. Found in Botucatu, Brazil, it was formally described as a new species in 2014 by lichenologists André Aptroot and Patrícia Jungbluth. The type specimen was collected by the authors from the botanical garden on the campus of Botucatu (São Paulo) at an altitude of . Description The lichen has a pale grey, shiny thallus that is tightly attached to its bark substrate; the lower surface is black, with simple (i.e., unbranched), black rhizines that help attach the thallus to its substrate. The lobes comprising the thallus are 0.7–1.2 mm wide, with rounded tips, and are sparsely covered with white spots (). Older parts of lobes develop pustules (pimple or blister-like swellings) that are about 0.1–0.3 mm wide and about 0.2–0.6 mm high; the species epithet refers to these characteristic structures. The cortex of the thallus contains lichexanthone, a lic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
André Aptroot
André Aptroot (Heemskerk, 1961) is a Dutch mycologist and lichenologist. In 1993 he did his PhD at the University of Utrecht under the supervision of Robbert Gradstein (nl). His dissertation was titled "Systematic studies on pyrenocarpous lichens and related fungi". He specializes in fungi and lichens on which he has several hundreds of publications to his name. He has worked as curator at Centraalbureau voor Schimmelcultures (now Westerdijk Institute). Aptroot is the founder of the Consultancy for Bryology and Lichenology, which is located in Soest where there is a herbarium with a collection of lichens mainly from the Netherlands and the tropics. From 2008 he has been collection manager at Pinetum Blijdenstein (nl) in Hilversum. He is a member of the International Association for Lichenology and the American Bryological and Lichenological Society. He is a visiting professor at the Federal University of Mato Grosso do Sul in Campo Grande, Brazil. Because of Aptroot's bro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichexanthone
Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of leafy lichen in the 1940s. The compound is known to occur in many lichens, and it is important in the taxonomy of species in several genera, such as ''Pertusaria'' and ''Pyxine''. More than a dozen lichen species have a variation of the word lichexanthone incorporated as part of their binomial name. The presence of lichexanthone in lichens causes them to fluoresce a greenish-yellow colour under long-wavelength UV light; this feature is used to help identify some species. Lichexanthone is also found in several plants (many are from the families Annonaceae and Rutaceae), and some species of fungi that do not form lichens. In lichens, the biosynthesis of lichexanthone occurs through a set of enzymatic reactions that start with the molecule acetyl-CoA and sequentially add successive units, forming a longe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichens Described In 2014
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 s. They may have tiny, leafless branches (); flat leaf-like structures ( |
Lichen Species
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 s. They may have tiny, leafless branches (); flat leaf-like structures ( |
Caliciales
Caliciales is an order of mostly lichenized fungi in the class Lecanoromycetes. It consists of two families: Caliciaceae and Physciaceae, which together contain 54 genera and more than 1200 species. The order was circumscribed by American botanist Charles Edwin Bessey in 1907. Families and genera , Species Fungorum (in the Catalogue of Life) accepts 2 families, 56 genera, and 910 species in the Caliciales. *Caliciaceae ::''Acolium'' – 5 spp. ::'' Acroscyphus'' – 1 sp. ::''Allocalicium'' – 1 sp. ::''Amandinea'' – 83 spp. ::''Australiaena'' – 1 sp. ::''Baculifera'' – 18 spp. ::''Buellia'' – 201 spp. ::'' Caliciella'' – 1 sp. ::''Calicium'' – 36 spp. ::''Chrismofulvea'' – 3 spp. ::''Ciposia'' – 1 sp. ::''Cratiria'' – 23 spp. ::''Dermatiscum'' – 2 sp. ::''Dermiscellum'' – 1 sp. ::''Dimelaena'' – 10 spp. ::''Diploicia'' – 6 spp. ::''Diplotomma'' – 12 spp. ::''Dirinaria'' – 18 spp. ::''Endohyalina'' – 10 sp. ::'' Fluctua'' – 1 sp. ::''Gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thin-layer Chromatography
Thin-layer chromatography (TLC) is a chromatography technique used to separate non-volatile mixtures. Thin-layer chromatography is performed on a sheet of an inert substrate such as glass, plastic, or aluminium foil, which is coated with a thin layer of adsorbent material, usually silica gel, aluminium oxide (alumina), or cellulose. This layer of adsorbent is known as the stationary phase. After the sample has been applied on the plate, a solvent or solvent mixture (known as the mobile phase) is drawn up the plate via capillary action. Because different analytes ascend the TLC plate at different rates, separation is achieved. It may be performed on the analytical scale as a means of monitoring the progress of a reaction, or on the preparative scale to purify small amounts of a compound. TLC is an analytical tool widely used because of its simplicity, relative low cost, high sensitivity, and speed of separation. TLC functions on the same principle as all chromatography: a com ... [...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] |
Terpenoid
The terpenoids, also known as isoprenoids, are a class of naturally occurring organic chemicals derived from the 5-carbon compound isoprene and its derivatives called terpenes, diterpenes, etc. While sometimes used interchangeably with "terpenes", terpenoids contain additional functional groups, usually containing oxygen. When combined with the hydrocarbon terpenes, terpenoids comprise about 80,000 compounds. They are the largest class of plant secondary metabolites, representing about 60% of known natural products. Many terpenoids have substantial pharmacological bioactivity and are therefore of interest to medicinal chemists. Plant terpenoids are used for their aromatic qualities and play a role in traditional herbal remedies. Terpenoids contribute to the scent of eucalyptus, the flavors of cinnamon, cloves, and ginger, the yellow color in sunflowers, and the red color in tomatoes. Well-known terpenoids include citral, menthol, camphor, salvinorin A in the plant '' Salvia di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UV Light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. For huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluoresce
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, than the absorbed radiation. A perceptible example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the electromagnetic spectrum (invisible to the human eye), while the emitted light is in the visible region; this gives the fluorescent substance a distinct color that can only be seen when the substance has been exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after. Fluorescence has many practical applications, including mineralogy, gemology, medicine, chemical sensors (fluorescence spectroscopy), fluorescent labelling, dyes, biological detectors, cosmic-ray detection, vacuu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichen Product
Lichen products, also known as lichen substances, are organic compounds produced by a lichen. Specifically, they are secondary metabolites. Lichen products are represented in several different chemical classes, including terpenoids, orcinol derivatives, chromones, xanthones, depsides, and depsidones. Over 800 lichen products of known chemical structure have been reported in the scientific literature, and most of these compound are exclusively found in lichens. Examples of lichen products include usnic acid (a dibenzofuran), atranorin (a depside), lichexanthone (a xanthone), salazinic acid (a depsidone), and isolichenan, an α-glucan. Many lichen products have biological activity, and research into these effects is ongoing. Lichen products accumulate on the outer walls of the fungal hyphae, and are quite stable. Crystal deposits can be visualised using scanning electron microscopy. For this reason, even very old herbarium specimens can be analysed. The amount of lichen products i ... [...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 als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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