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Phytophthora Alni
''Phytophthora alni'' is an oomycete plant pathogen that causes lethal root and collar rot in alders. It is widespread across Europe and has recently been found in North America. This species is believed to have originated relatively recently. Classification ''Phytophythora alni'' was discovered in 1993 in Southern Britain. It has subsequently been reported in many European countries including the Netherlands, Germany, France, Sweden, Belgium, Austria and Hungary and has recently been found in Alaska. ''P. alni'' consists of three subspecies, the most commonly isolated and most virulent subspecies ''P. alni alni'' (also referred to as the 'standard form') and two less commonly isolated subspecies ''P. alni uniformis'' (also called the Swedish variant) and ''P. alni multiformis'' (which contains the Dutch, German and UK variants). A recent genetic analysis has suggested that ''P. alni alni.'' was generated on many separate occasions by the hybridization of either ''P. alni uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brasier (mycologist)
Brasier was a French automobile manufacturer, based in the Paris conurbation, and active between 1905 and 1930. The firm began as Richard-Brasier in 1902, and became known as Chaigneau-Brasier in 1926. __TOC__ Origins Charles-Henri Brasier worked briefly with Panhard and then for some years with Émile Mors before, at the age of 35, he set himself up as an automobile manufacturer on his own account. He did this in partnership with Georges Richard, the two of them establishing the Richard-Brasier business in 1902. By 1905, relations had broken down between the partners due to Richard being frequently away from his desk due to his motor racing activities and, it was reported, injuries he sustained as a result. The strained relations prompted Richard to leave the company that year to found Unic. The newly renamed Brasier firm was therefore born into an atmosphere of recrimination and litigation. Nevertheless, Brasier retained the premises originally acquired by the Richard- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyploidy
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei ( eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains one or more chromosomes and comes from each of two parents, resulting in pairs of homologous chromosomes between sets. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by mei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riparian
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by hydrophilic plants. Riparian zones are important in ecology, environmental resource management, and civil engineering because of their role in soil conservation, their habitat biodiversity, and the influence they have on fauna and aquatic ecosystems, including grasslands, woodlands, wetlands, or even non-vegetative areas. In some regions, the terms riparian woodland, riparian forest, riparian buffer zone, riparian corridor, and riparian strip are used to characterize a riparian zone. The word ''riparian'' is derived from Latin '' ripa'', meaning " river bank". Characteristics Riparian zones may be natural or engineered for soil stabilization or restoration. These zones are important natural b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phloem
Phloem (, ) is the living biological tissue, tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This transport process is called translocation. In trees, the phloem is the innermost layer of the bark (botany), bark, hence the name, derived from the Ancient Greek word (''phloiós''), meaning "bark". The term was introduced by Carl Nägeli in 1858. Structure Phloem tissue consists of conducting Cell (biology), cells, generally called sieve elements, Ground tissue#Parenchyma, parenchyma cells, including both specialized companion cells or albuminous cells and unspecialized cells and supportive cells, such as fibres and sclereids. Conducting cells (sieve elements) Sieve elements are the type of cell that are responsible for transporting sugars throughout the plant. At maturity they lack a Cell nucleus, nucleus and have very few organelles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prunus Avium
''Prunus avium'', commonly called wild cherry, sweet cherry, gean, or bird cherryWorld Economic Plants: A Standard Reference, Second Edition'. CRC Press; 19 April 2016. . p. 833–. is a species of cherry, a flowering plant in the rose family, Rosaceae. It is native to Europe, Anatolia, Maghreb, and Western Asia, from the British Isles south to Morocco and Tunisia, north to the Trondheimsfjord region in Norway and east to the Caucasus and northern Iran, with a small isolated population in the western Himalaya.Den Virtuella Floran''Prunus avium''(in Swedish; witmap The species is widely cultivated in other regions and has become naturalized in North America and Australia. ''Prunus avium'' has a diploid set of sixteen chromosomes (2''n'' = 16). All parts of the plant except for the ripe fruit are slightly toxic, containing cyanogenic glycosides. Description ''Prunus avium'' is a deciduous tree growing to tall, with a trunk up to in diameter. Young trees show strong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castanea Sativa
''Castanea sativa'', the sweet chestnut, Spanish chestnut or just chestnut, is a species of tree in the family Fagaceae, native to Southern Europe and Asia Minor, and widely cultivated throughout the temperate world. A substantial, long-lived deciduous tree, it produces an edible seed, the chestnut, which has been used in cooking since ancient times. Description ''C. sativa'' attains a height of with a trunk often in diameter. Around 20 trees are recorded with diameters over including one in diameter at breast height. A famous ancient tree known as the Hundred Horse Chestnut in Sicily was historically recorded at in diameter (although it has split into multiple trunks above ground). The bark often has a net-shaped (retiform) pattern with deep furrows or fissures running spirally in both directions up the trunk. The trunk is mostly straight with branching starting at low heights. The oblong-lanceolate, boldly toothed leaves are long and broad. The flowers of both sexe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juglans Regia
''Juglans regia'', the Persian walnut, English walnut, Carpathian walnut, Madeira walnut, or especially in Great Britain, common walnut, is an Old World walnut tree species native to the region stretching from the Balkans eastward to the Himalayas and southwest China. It is widely cultivated across Europe. It is the origin of cultivated varieties which produce the edible walnut, consumed around the world. China is the major commercial producer of walnuts. Description ''Juglans regia'' is a large deciduous tree, attaining heights of , and a trunk up to 2 m (6 ft) in diameter, commonly with a short trunk and broad crown. The bark is smooth, olive-brown when young and silvery-grey on older branches, and features scattered broad fissures with a rougher texture. Like all walnuts, the pith of the twigs contains air spaces; this chambered pith is brownish in color. The leaves are alternately arranged, 25–40 cm (10 to 16 in) long, odd-pinnate with 5–9 leaflets, paire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alnus Viridis
''Alnus alnobetula'' is a common tree widespread across much of Europe, Asia, and North America. Many sources refer to it as ''Alnus viridis'', the green alder, but botanically this is considered an illegitimate name synonymous with ''Alnus alnobetula'' subsp. ''fruticosa''. Description It is a large shrub or small tree tall with smooth grey bark even in old age. The leaves are shiny green with light green undersurfaces, ovoid, long and 2–6 cm broad. The flowers are catkins, appearing late in spring after the leaves emerge (unlike other alders which flower before leafing out); the male catkins are pendulous, 4–8 cm long, the female catkins 1 cm long and 0.7 cm broad when mature in late autumn, in clusters of 3–10 on a branched stem. The seeds are small, long, light brown with a narrow encircling wing. The roots of ''Alnus viridis subsp. sinuata'' have nitrogen-fixing nodules. A study in Alaska showed that Sitka alder seedlings were able to invade coa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alnus Incana
''Alnus incana'', the grey alder or speckled alder, is a species of multi-stemmed, shrubby tree in the birch family, with a wide range across the cooler parts of the Northern Hemisphere. Tolerant of wetter soils, it can slowly spread with runners and is a common sight in swamps and wetlands. It is easily distinguished by its small cones, speckled bark and broad leaves. Description It is a small- to medium-sized tree tall with smooth grey bark even in old age, its life span being a maximum of 60 to 100 years. The leaves are matte green, ovoid, long and broad. The flowers are catkins, appearing early in spring before the leaves emerge, the male catkins pendulous and long, the female catkins long and one cm broad when mature in late autumn. The seeds are small, long, and light brown with a narrow encircling wing. The grey alder has a shallow root system, and is marked not only by vigorous production of stump suckers, but also by root suckers, especially in the northern par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alnus Glutinosa
''Alnus glutinosa'', the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations where its association with the bacterium ''Frankia alni'' enables it to grow in poor quality soils. It is a medium-sized, short-lived tree growing to a height of up to 30 metres (98 feet). It has short-stalked rounded leaves and separate male and female flowers in the form of catkins. The small, rounded fruits are cone-like and the seeds are dispersed by wind and water. The common alder provides food and shelter for wildlife, with a number of insects, lichens and fungi being completely dependent on the tree. It is a pioneer species, colonising vacant land and forming mixed forests as other trees appear in its wake. Eventually common alder dies out of woodlands because the seedlings need more light than is available on the forest floor. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alnus Cordata
''Alnus cordata'', the Italian alder, is a tree or shrub species belonging to the family Betulaceae, and native to the southern Apennine Mountains (Campania, Basilicata and Calabria, mainly on western mountain sides) and the north-eastern mountains of Corsica. It has been introduced in Sicily, Sardinia, and more recently in Central-Northern Italy, other European countries (France, Belgium, Spain, Portugal, United Kingdom) and extra-European countries (Chile, New Zealand), where it has become naturalised. Description It is a medium-sized tree growing up to tall (exceptionally to ), with a trunk up to in diameter. The leaves are deciduous but with a very long season in leaf, from April to December in the Northern Hemisphere; they are alternate, cordate (heart-shaped), rich glossy green, long, with a finely serrated margin. The slender cylindrical male catkins are pendulous, reddish and up to long; pollination is in early spring, before the leaves emerge. The female catkins are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sporangium
A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cycle. Sporangia can produce spores by mitosis, but in nearly all land plants and many fungi, sporangia are the site of meiosis and produce genetically distinct haploid spores. Fungi In some phyla of fungi, the sporangium plays a role in asexual reproduction, and may play an indirect role in sexual reproduction. The sporangium forms on the sporangiophore and contains haploid nuclei and cytoplasm. Spores are formed in the sporangiophore by encasing each haploid nucleus and cytoplasm in a tough outer membrane. During asexual reproduction, these spores are dispersed via wind and germinate into haploid hyphae. Although sexual reproduction in fungi varies between phyla, for some fungi the sporangium plays an indirect role in sexual reprod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
