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43-420: According to the most probable theory, the name has its origin in the word jasan , i.e. ' ash '. Jeseník (respectively Jesenný potok ) was first the name of a stream that flowed through an ash forest in a valley. The name was Germanized to Gesenke (i.e. 'slope') and used as a name of a small town that was founded in the valley (but later disappeared), and then it was transferred first to the valley, and then to

86-458: A biological control for the management of EAB populations in the United States. The public is being cautioned to avoid transporting unfinished wood products, such as firewood, to slow the spread of this insect pest. Damage occurs when emerald ash borer larvae feed on the inner bark, phloem , inside branches and tree trunks. Feeding on the phloem prevents nutrients and water transportation. If

129-447: A "stem". They demonstrated that these interacting particles can access novel dynamical phenomena beyond what botany yields: a "dynamical phyllotaxis" family of non local topological solitons emerge in the nonlinear regime of these systems, as well as purely classical rotons and maxons in the spectrum of linear excitations. Close packing of spheres generates a dodecahedral tessellation with pentaprismic faces. Pentaprismic symmetry

172-671: A considerable litter problem with their seeds. Rowans or mountain ashes have leaves and buds superficially similar to those of true ashes, but belong to the unrelated genus Sorbus in the rose family . The tree's common English name, "ash", traces back to the Old English æsc , which relates to the Proto-Indo-European for the tree, while the generic name originated in Latin from a Proto-Indo-European word for birch. Both words are also used to mean " spear " in their respective languages, as

215-448: A cylinder (rhombic lattices). Douady et al. showed that phyllotactic patterns emerge as self-organizing processes in dynamic systems. In 1991, Levitov proposed that lowest energy configurations of repulsive particles in cylindrical geometries reproduce the spirals of botanical phyllotaxis. More recently, Nisoli et al. (2009) showed that to be true by constructing a "magnetic cactus" made of magnetic dipoles mounted on bearings stacked along

258-498: A few species. The seeds, popularly known as "keys" or "helicopter seeds", are a type of fruit known as a samara . Some Fraxinus species are dioecious , having male and female flowers on separate plants but sex in ash is expressed as a continuum between male and female individuals, dominated by unisexual trees. With age, ash may change their sexual function from predominantly male and hermaphrodite towards femaleness ; if grown as an ornamental and both sexes are present, ashes can cause

301-629: A flat highland or low mountain range with an altitude that most often ranges between 400 and 600 metres above sea level. It is bordered with the Hrubý Jeseník and Zlatohorská Highlands in the north, with the Upper Morava Valley in the west, with the Moravian Gate in the south, and with the Opava Hilly Land and Ostrava Basin in the east. Nízký Jeseník is further subdivided into

344-449: A full rotation. In beech and hazel the angle is 1/3, in oak and apricot it is 2/5, in sunflowers , poplar , and pear , it is 3/8, and in willow and almond the angle is 5/13. The numerator and denominator normally consist of a Fibonacci number and its second successor. The number of leaves is sometimes called rank, in the case of simple Fibonacci ratios, because the leaves line up in vertical rows. With larger Fibonacci pairs,

387-517: A good food source for the frogs, but also reduces its resistance to the ash borer . Species with higher leaf tannin levels (including maples and non-native ash species) are taking the place of native ash, thanks to their greater resistance to the ash borer. They produce much less suitable food for the tadpoles, resulting in poor survival rates and small frog sizes. Ash species native to North America also provide important habitat and food for various other creatures native to North America. This includes

430-477: A reduction in the supply of healthy trees, especially in Europe, is making ash an increasingly expensive option. Ash was commonly used for the structural members of the bodies of cars made by carriage builders. Early cars had frames which were intended to flex as part of the suspension system to simplify construction. The Morgan Motor Company of Great Britain still manufactures sports cars with frames made from ash. It

473-416: Is a genus of plants in the olive and lilac family, Oleaceae , and comprises 45–65 species of usually medium-to-large trees , most of which are deciduous trees, although some subtropical species are evergreen trees. The genus is widespread throughout much of Europe, Asia, and North America. The leaves are opposite (rarely in whorls of three), and mostly pinnately compound , though simple in

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516-469: Is a tonewood commonly used in the manufacture of electric guitars . It exhibits a pronounced bright tone with a scooped midrange. It is lightweight, easy to work and sand, accepts glue, stain , paint and finish very well and is inexpensive. All this has made it a favourite of large factories mass-producing instruments. The Fender musical instrument company has been continuously and uninterruptedly using Ash to make electric guitars since 1956. Swamp ash

559-562: Is a wood-boring beetle accidentally introduced to North America from eastern Asia via solid wood packing material in the late 1980s to early 1990s. It has killed tens of millions of trees in 22 states in the United States and adjacent Ontario and Quebec in Canada. It threatens some seven billion ash trees in North America. Research is being conducted to determine whether three native Asian wasps that are natural predators of EAB could be used as

602-408: Is also used for making drum shells . Woodworkers generally consider ash a "poor cousin" to the other major open pore wood, oak, but it is useful in any furniture application. Ash veneers are extensively used in office furniture. Ash is not used much outdoors due to the heartwood having a low durability to ground contact, meaning it will typically perish within five years. The F. japonica species

645-444: Is favored as a material for making baseball bats by Japanese sporting-goods manufacturers. Its robust structure, good looks, and flexibility combine to make ash ideal for staircases. Ash stairs are extremely hard-wearing, which is particularly important for treads. Due to its elasticity, ash can also be steamed and bent to produce curved stair parts such as volutes (curled sections of handrail) and intricately shaped balusters. However,

688-462: Is related to the Fibonacci series and the golden section of classical geometry. Phyllotaxis has been used as an inspiration for a number of sculptures and architectural designs. Akio Hizume has built and exhibited several bamboo towers based on the Fibonacci sequence which exhibit phyllotaxis. Saleh Masoumi has proposed a design for an apartment building in which the apartment balconies project in

731-603: Is the largest mesoregion and mountain range in the country. The most notable river in the territory are the Oder , which originates in the Oderské vrchy , the Moravice , where the reservoirs Kružberk and Slezská Harta are built, and the Opava , whose upper course flows through the north of the territory. The Bystřice also originates there and drains the southwestern part of the range. Just beyond

774-444: Is used a lot in guitar building because of its figure. It is a choice of material for electric guitar bodies and, less commonly, for acoustic guitar bodies, known for its bright, cutting edge and sustaining quality. Some Fender Stratocasters and Telecasters are made of ash, (such as Bruce Springsteen 's Telecaster on the Born to Run album cover), as an alternative to alder. Ash

817-638: Is widely planted as a street tree in the United States. The inner bark of the blue ash ( F. quadrangulata ) has been used as a source for blue dye . In Sicily, Italy, sugars are obtained by evaporating the sap of the manna ash , extracted by making small cuts in the bark. The manna ash, native to southern Europe and southwest Asia, produces a blue-green sap, which has medicinal value as a mild laxative, demulcent, and weak expectorant. The young seedpods of Ash trees, also known as "keys", are edible for human consumption. In Britain, they are traditionally pickled with vinegar, sugar and spices. In Greek mythology ,

860-645: The Aizoaceae . In genera of the Aizoaceae, such as Lithops and Conophytum , many species have just two fully developed leaves at a time, the older pair folding back and dying off to make room for the decussately oriented new pair as the plant grows. If the arrangement is both distichous and decussate, it is called secondarily distichous . The whorled arrangement is fairly unusual on plants except for those with particularly short internodes . Examples of trees with whorled phyllotaxis are Brabejum stellatifolium and

903-478: The Fibonacci sequence in 1837. Insight into the mechanism had to wait until Wilhelm Hofmeister proposed a model in 1868. A primordium , the nascent leaf, forms at the least crowded part of the shoot meristem . The golden angle between successive leaves is the blind result of this jostling. Since three golden arcs add up to slightly more than enough to wrap a circle, this guarantees that no two leaves ever follow

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946-553: The Meliae are nymphs associated with the ash, perhaps specifically of the manna ash ( Fraxinus ornus ), as dryads were nymphs associated with the oak . They appear in Hesiod 's Theogony, which states that they were born when drops of Ouranos's blood fell on the earth (Gaia). In Norse mythology , a vast, evergreen ash tree Yggdrasil ("the steed ( gallows ) of Odin "), watered by three magical springs, serves as axis mundi , sustaining

989-592: The Quaternary , there were five active stratovolcanoes , including Velký Roudný, Malý Roudný, Uhlířský vrch, Venušina sopka and Červená hora. With an age of 1.5 million years, these are the youngest volcanoes in the Czech Republic. The territory roughly stretches from Olomouc (southwest) to Ostrava (east), and to Krnov (north). Nízký Jeseník has an area of 2,894 square kilometres (1,117 sq mi) and an average elevation of 482.5 metres (1,583 ft). It

1032-625: The fungus Hymenoscyphus fraxineus , causing ash dieback in a large number of trees since the mid-1990s, particularly in eastern and northern Europe. The disease has infected about 90% of Denmark's ash trees. At the end of October 2012 in the UK, the Department for Environment, Food and Rural Affairs (Defra) reported that ash dieback had been discovered in mature woodland in Suffolk ; previous occurrences had been on young trees imported from Europe. In 2016,

1075-712: The meristem close to where the leaf was initiated. This gives rise to a self-propagating system that is ultimately controlled by the ebb and flow of auxin in different regions of the meristematic topography . Some early scientists—notably Leonardo da Vinci —made observations of the spiral arrangements of plants. In 1754, Charles Bonnet observed that the spiral phyllotaxis of plants were frequently expressed in both clockwise and counter-clockwise golden ratio series. Mathematical observations of phyllotaxis followed with Karl Friedrich Schimper and his friend Alexander Braun 's 1830 and 1830 work, respectively; Auguste Bravais and his brother Louis connected phyllotaxis ratios to

1118-408: The arrangement of leaves on a plant stem . Phyllotactic spirals form a distinctive class of patterns in nature . The basic arrangements of leaves on a stem are opposite and alternate (also known as spiral ). Leaves may also be whorled if several leaves arise, or appear to arise, from the same level (at the same node ) on a stem. With an opposite leaf arrangement, two leaves arise from

1161-487: The ash is attacked, the branches can die and eventually the whole tree can as well. Ways to detect emerald ash borer infestation include seeing bark peeling off, vertical cracks in the bark, seeing galleries within the tree that contain powdery substance, and D-shaped exit holes on the branches or trunk. Not all of these may be present, but any of these warning signs could be an indication of possible infestation. The European ash, Fraxinus excelsior , has been affected by

1204-401: The ash tree was reported as in danger of extinction in Europe. Ash is a hardwood and is dense (within 20% of 670 kg/m for Fraxinus americana , and higher at 710 kg/m for Fraxinus excelsior ), tough and very strong but elastic , extensively used for making bows , tool handles, baseball bats , hurleys , and other uses demanding high strength and resilience . Ash

1247-604: The borders are several larger cities, but right in the territory, despite its size, there are not many. A significant part of Nízký Jeseník belongs to the Libavá Military Training Area . The most populated settlements entirely located in Nízký Jeseník are Bruntál , Odry , Vítkov and Fulnek , and partly located in the territory are Krnov , Šternberk and Bílovec . Fraxinus Fraxinus ( / ˈ f r æ k s ɪ n ə s / ), commonly called ash ,

1290-443: The details. Botanists are divided on whether the control of leaf migration depends on chemical gradients among the primordia or purely mechanical forces. Lucas numbers rather than Fibonacci numbers have been observed in a few plants and occasionally, the leaf positioning appears to be random. Physical models of phyllotaxis date back to Airy 's experiment of packing hard spheres. Gerrit van Iterson diagrammed grids imagined on

1333-417: The larvae of multiple long-horn beetles , as well as other insects including those in the genus Tropidosteptes , lace bugs , aphids , larvae of gall flies , and caterpillars. Birds are also interested in black, green, and white ash trees. The black ash alone supports wood ducks , wild turkey , cardinals , pine grosbeaks , cedar waxwings , and yellow-bellied sapsuckers , with habitat and food (such as

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1376-455: The microregions of Brantice Highlands, Bruntál Highlands, Domašov Highlands, Oderské vrchy , Slunečná Highlands, Stěbořice Highlands, Vítkov Highlands and Tršice Hills. Nízký Jeseník includes the best-preserved extinct volcanoes in Moravia . The highest peaks are: Nízký Jeseník originated in the older Proterozoic . Geologically, it is one of the oldest mountain ranges in the Czech Republic. In

1419-448: The nine worlds of the cosmos in its roots and branches. Askr , the first man in Norse myth, literally means 'ash'. In Italian folklore , an ash stake could be used to kill a vampire . Opposite leaves In botany , phyllotaxis (from Ancient Greek φύλλον ( phúllon )  'leaf' and τάξις ( táxis )  'arrangement') or phyllotaxy is

1462-438: The numbers appear to be multiples of Fibonacci numbers because the spirals consist of whorls. The pattern of leaves on a plant is ultimately controlled by the accumulation of the plant hormone auxin in certain areas of the meristem . Leaves become initiated in localized areas where auxin concentration is higher. When a leaf is initiated and begins development, auxin begins to flow towards it, thus depleting auxin from area on

1505-486: The pattern becomes complex and non-repeating. This tends to occur with a basal configuration. Examples can be found in composite flowers and seed heads. The most famous example is the sunflower head. This phyllotactic pattern creates an optical effect of criss-crossing spirals. In the botanical literature, these designs are described by the number of counter-clockwise spirals and the number of clockwise spirals. These also turn out to be Fibonacci numbers . In some cases,

1548-461: The related genus Macadamia . A whorl can occur as a basal structure where all the leaves are attached at the base of the shoot and the internodes are small or nonexistent. A basal whorl with a large number of leaves spread out in a circle is called a rosette . The rotational angle from leaf to leaf in a repeating spiral can be represented by a fraction of a full rotation around the stem. Alternate distichous leaves will have an angle of 1/2 of

1591-475: The same radial line from center to edge. The generative spiral is a consequence of the same process that produces the clockwise and counter-clockwise spirals that emerge in densely packed plant structures, such as Protea flower disks or pinecone scales. In modern times, researchers such as Mary Snow and George Snow continued these lines of inquiry. Computer modeling and morphological studies have confirmed and refined Hoffmeister's ideas. Questions remain about

1634-401: The sap being of interest to the sapsucker) among others. Many mammalian species from meadow voles eating the seeds to white-tailed deer eating the foliage to silver-haired bats nesting will also make use of ash trees. Ash is used as a food plant by the larvae of some Lepidoptera species ( butterflies and moths ). The emerald ash borer ( Agrilus planipennis ), also called EAB,

1677-463: The stem at the same level (at the same node ), on opposite sides of the stem. An opposite leaf pair can be thought of as a whorl of two leaves. With an alternate (spiral) pattern, each leaf arises at a different point (node) on the stem. Distichous phyllotaxis, also called "two-ranked leaf arrangement" is a special case of either opposite or alternate leaf arrangement where the leaves on a stem are arranged in two vertical columns on opposite sides of

1720-441: The stem. Examples include various bulbous plants such as Boophone . It also occurs in other plant habits such as those of Gasteria or Aloe seedlings, and also in mature plants of related species such as Kumara plicatilis . In an opposite pattern, if successive leaf pairs are 90 degrees apart, this habit is called decussate . It is common in members of the family Crassulaceae Decussate phyllotaxis also occurs in

1763-568: The whole mountain range. Later the name was changed back to Czech Jeseník . Jeseníky (plural form of Jeseník) is a collective term for an area that includes the mountain ranges of Nízký Jeseník (i.e. 'low Jeseník') and Hrubý Jeseník (literally 'rough Jeseník'). Nízký Jeseník is a mesoregion of the Eastern Sudetes , which is part of the Sudetes within the Bohemian Massif . It is described as

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1806-460: The wood is good for shafts. Species are arranged into sections supported by phylogenetic analysis: North American native ash tree species are a critical food source for North American frogs, as their fallen leaves are particularly suitable for tadpoles to feed upon in ponds (both temporary and permanent), large puddles, and other water bodies. Lack of tannins in the American ash makes their leaves

1849-402: Was also widely used by early aviation pioneers for aircraft construction. It lights and burns easily, so is used for starting fires and barbecues , and is usable for maintaining a fire, though it produces only a moderate heat. The two most economically important species for wood production are white ash, in eastern North America, and European ash in Europe. The green ash ( F. pennsylvanica )

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