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Tar Spot
''Rhytisma acerinum'' is a plant pathogen that commonly affects sycamores and maples in late summer and autumn, causing tar spot. Tar spot does not usually have an adverse effect on the trees' long-term health. ''R. acerinum'' is an Ascomycete fungus that locally infects the leaves of trees and is a biotrophic parasite.Roland W.S. Weber and John Webster (2002). Teaching techniques for mycology: 18. ''Rhytisma acerinum'', cause of tar-spot disease of sycamore leaves. Mycologist, 16, pp 120-123 The disease is cosmetic and is therefore usually controlled only with sanitation methods.Hudelson, Brian. Wisconsin Horticulture UW-Extension Cooperative Extension. UW-Madison Plant Pathology, April 25, 2004. Web. Oct. 22, 2011. Symptoms and signs In late spring, chlorotic spots appear on tree leaves. These develop into brown-black lesions, retaining the yellow border. The lesions continue to grow, and by the end of summer form leaf spots that look like tar. The spot can grow up to in diame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acer Saccharum
''Acer saccharum'', the sugar maple, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is native to the hardwood forests of eastern Canada and eastern United States. Sugar maple is best known for being the primary source of maple syrup and for its brightly colored fall foliage. It may also be known as "rock maple", "sugar tree", "birds-eye maple", "sweet maple", "curly maple", or "hard maple", particularly when referring to the wood. Description ''Acer saccharum'' is a deciduous tree normally reaching heights of , and exceptionally up to . A 10-year-old tree is typically about tall. As with most trees, forest-grown sugar maples form a much taller trunk and narrower canopy than open-growth ones. The leaves are deciduous, up to long and wide, palmate, with five lobes and borne in opposite pairs. The basal lobes are relatively small, while the upper lobes are larger and deeply notched. In contrast with the angular notching of the silver mapl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acer Saccharinum
''Acer saccharinum'', commonly known as silver maple, creek maple, silverleaf maple, soft maple, large maple, water maple, swamp maple, or white maple, is a species of maple native to the eastern and central United States and southeastern Canada. It is one of the most common trees in the United States. Although the silver maple's Latin name is similar, it should not be confused with '' Acer saccharum'', the sugar maple. Some of the common names are also applied to other maples, especially ''Acer rubrum''. Description The silver maple tree is a relatively fast-growing deciduous tree, commonly reaching a height of , exceptionally . Its spread will generally be wide. A 10-year-old sapling will stand about tall. It is often found along waterways and in wetlands, leading to the colloquial name "water maple". It is a highly adaptable tree, although it has higher sunlight requirements than other maple trees. The leaves are simple and palmately veined, long and broad, with deep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllachora Maydis
''Phyllachora maydis'' is a plant pathogen causing ascomycete diseases in maize/corn, and is more commonly referred to as ''tar spot''. Identified by the distinctive development of stroma, this pathogen in itself is of little economic importance in the production of corn. However, the accompanying fungal infection of ''Monographella maydis,'' identified by “fish-eye” lesions, was claimed to cause significant foliar damage and subsequently yield reduction. there is insufficient information about this pathogen and its management. Symptoms and signs This pathogen is an obligate parasite solely of the species ''Zea mays''. The first symptoms are yellowing spots on both upper and lower leaf surfaces. Within the spot develops the characteristic black stromata over the ascomata, along with chlorosis of surrounding tissue. The chlorotic rings may be elliptical, circular, or may conjoin to form striping up to long. Some of the chlorotic tissue around the ascomata may become necrot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equine Atypical Myopathy
Equine atypical myopathy, also known as atypical myoglobinuria, or EAM is a fatal disease of horses (equidae) characterized by acute rhabdomyolysis. It is caused by the ingestion of the seeds or young shoots of sycamore tree. EAM has a high fatality rate. Cause Atypical myopathy is a commonly fatal form of equine rhabdomyolysis caused by the toxin Hypoglycin A (HGA). HGA is a naturally-occurring amino acid contained by trees and shrubs of Sapindaceae family. Horses can become poisoned by eating the seeds or seedlings of Acer pseudoplatanus (called Sycamore in the UK or more widely Sycamore Maple) or Acer negundo (Box Elder). The amount of HGA in sycamore seeds may vary. The toxin affects to the functioning of horse’s muscle cells by slowing down or stopping the energy production. Even if atypical myopathy is not contagious it can affect either to individual horse or several horses in the same stock. Some horses may be more resistant to the toxin than others due to genetic diffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christiaan Hendrik Persoon
Christiaan Hendrik Persoon (1 February 1761 – 16 November 1836) was a German mycologist who made additions to Linnaeus' mushroom taxonomy. Early life Persoon was born in South Africa at the Cape of Good Hope, the third child of an immigrant Pomeranian father and Dutch mother. His mother died soon after he was born; at the age of thirteen his father (who died a year later) sent him to Europe for his education. Education Initially studying theology at Halle, at age 22 (in 1784) Persoon switched to medicine at Leiden and Göttingen. He received a doctorate from the "Kaiserlich-Leopoldinisch-Carolinische Deutsche Akademie der Naturforscher" in 1799. Later years He moved to Paris in 1802, where he spent the rest of his life, renting an upper floor of a house in a poor part of town. He was apparently unemployed, unmarried, poverty-stricken and a recluse, although he corresponded with botanists throughout Europe. Because of his financial difficulties, Persoon agreed to dona ... [...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 conidium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromatolite
Stromatolites () or stromatoliths () are layered sedimentary formations (microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria). These microorganisms produce adhesive compounds that cement sand and other rocky materials to form mineral "microbial mats". In turn, these mats build up layer by layer, growing gradually over time. A stromatolite may grow to a meter or more. Although they are rare today, fossilized stromatolites provide records of ancient life on Earth. Morphology Stromatolites are layered, biochemical, accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains in biofilms (specifically microbial mats), through the action of certain microbial lifeforms, especially cyanobacteria. They exhibit a variety of forms and structures, or morphologies, including conical, stratiform, domal, columnar, and branching ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conidiophores
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an Asexual reproduction, asexual, non-motility, 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 (biology), 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, Metarhizium'') species. The terms microconidia and macroconidi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anamorph
In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a fruiting body. *Anamorph: an asexual reproductive stage (morph), often mold-like. When a single fungus produces multiple morphologically distinct anamorphs, these are called synanamorphs. *Holomorph: the whole fungus, including anamorphs and teleomorph. Dual naming of fungi Fungi are classified primarily based on the structures associated with sexual reproduction, which tend to be evolutionarily conserved. However, many fungi reproduce only asexually, and cannot easily be classified based on sexual characteristics; some produce both asexual and sexual states. These problematic species are often members of the Ascomycota, but a few of them belong to the Basidiomycota. Even among fungi that reproduce both sexually and asexually, often only one method of reproduction can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorosis
In botany, chlorosis is a condition in which leaves produce insufficient chlorophyll. As chlorophyll is responsible for the green color of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to manufacture carbohydrates through photosynthesis and may die unless the cause of its chlorophyll insufficiency is treated and this may lead to a plant diseases called rusts, although some chlorotic plants, such as the albino ''Arabidopsis thaliana'' mutant ''ppi2'', are viable if supplied with exogenous sucrose. The word ''chlorosis'' is derived from the Greek ''khloros'' meaning "greenish-yellow", "pale green", "pale", "pallid", or "fresh". In viticulture, the most common symptom of poor nutrition in grapevines is the yellowing of grape leaves caused by chlorosis and the subsequent loss of chlorophyll. This is often seen in vineyard soils that are high in limestone such as the Italian wine region of Barolo in the Piedmont, the Spanish wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stoma
In botany, a stoma (from Greek ''στόμα'', "mouth", plural "stomata"), also called a stomate (plural "stomates"), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange. The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatal opening. The term is usually used collectively to refer to the entire stomatal complex, consisting of the paired guard cells and the pore itself, which is referred to as the stomatal aperture. Air, containing oxygen, which is used in respiration, and carbon dioxide, which is used in photosynthesis, passes through stomata by gaseous diffusion. Water vapour diffuses through the stomata into the atmosphere in a process called transpiration. Stomata are present in the sporophyte generation of all land plant groups except liverworts. In vascular plants the number, size and distribution of stomata varies widely. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apothecia
An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are most commonly bowl-shaped (apothecia) but may take on a spherical or flask-like form that has a pore opening to release spores (perithecia) or no opening (cleistothecia). Classification The ascocarp is classified according to its placement (in ways not fundamental to the basic taxonomy). It is called ''epigeous'' if it grows above ground, as with the morels, while underground ascocarps, such as truffles, are termed ''hypogeous''. The structure enclosing the hymenium is divided into the types described below (apothecium, cleistothecium, etc.) and this character ''is'' important for the taxonomic classification of the fungus. Apothecia can be relatively large and fleshy, whereas the others are microscopic—about the size of flecks of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
