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Rock Elm
''Ulmus thomasii'', the rock elm or cork elm (or orme liège in Québec), is a deciduous tree native primarily to the Midwestern United States. The tree ranges from southern Ontario and Quebec, south to Tennessee, west to northeastern Kansas, and north to Minnesota. Etymology The tree was named in 1902 for David Thomas, an American civil engineer who had first named and described the tree in 1831 as ''Ulmus racemosa''. Description ''Ulmus thomasii'' grows as a tree from tall, and may live for up to 300 years. Where forest-grown, the crown is cylindrical and upright with short branches, and is narrower than most other elms. Rock elm is also unusual among North American elms in that it is often monopodial.Bean, W. J. (1981). ''Trees and shrubs hardy in Great Britain'', 7th edition. Murray, London. The bark is grey-brown and deeply furrowed into scaly, flattened ridges. Many older branches have 3–4 irregular thick corky wings. It is for this reason the rock elm is sometim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Sprague Sargent
Charles Sprague Sargent (April 24, 1841 – March 22, 1927) was an American botanist. He was appointed in 1872 as the first director of Harvard University's Arnold Arboretum in Boston, Massachusetts, and held the post until his death. He published several works of botany. The standard botanical author abbreviation Sarg. is applied to plants he identified. Early life Sargent was the second son of Henrietta (Gray) and Ignatius Sargent, a Boston merchant and banker who grew wealthy on railroad investments. He grew up on his father's 130-acre (53-ha) estate in Brookline, Massachusetts. He attended Harvard College, where he graduated in Biology in the class of 1862. Sargent enlisted in the Union Army later that year, saw service in Louisiana during the American Civil War, and was mustered out in 1865. He traveled in Europe and Asia for three years. Career Having returned to his family's Brookline estate, "Holmlea", Sargent took over its management as a horticulturist, influence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfect Flower
Plant reproductive morphology is the study of the physical form and structure (the morphology) of those parts of plants directly or indirectly concerned with sexual reproduction. Among all living organisms, flowers, which are the reproductive structures of angiosperms, are the most varied physically and show a correspondingly great diversity in methods of reproduction. Plants that are not flowering plants (green algae, mosses, liverworts, hornworts, ferns and gymnosperms such as conifers) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, depends on the reproductive morphology, and is the single most important determinant of the genetic structure of nonclonal plant populations. Christian Konrad Sprengel (1793) studied the reproduction of flowering plants and for the first time it was understood that the pollination process involve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winchester, Hampshire
Winchester is a cathedral city in Hampshire, England. The city lies at the heart of the wider City of Winchester, a local government district, at the western end of the South Downs National Park, on the River Itchen. It is south-west of London and from Southampton, its nearest city. At the 2011 census, Winchester had a population of 45,184. The wider City of Winchester district, which includes towns such as Alresford and Bishop's Waltham, has a population of 116,595. Winchester is the county town of Hampshire and contains the head offices of Hampshire County Council. Winchester developed from the Roman town of Venta Belgarum, which in turn developed from an Iron Age oppidum. Winchester was one of the most important cities in England until the Norman conquest in the eleventh century. It has since become one of the most expensive and affluent areas in the United Kingdom. The city's major landmark is Winchester Cathedral. The city is also home to the University of Winchester ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arboretum
An arboretum (plural: arboreta) in a general sense is a botanical collection composed exclusively of trees of a variety of species. Originally mostly created as a section in a larger garden or park for specimens of mostly non-local species, many modern arboreta are in botanical gardens as living collections of woody plants and is intended at least in part for scientific study. In Latin, an ''arboretum'' is a place planted with trees, not necessarily in this specific sense, and "arboretum" as an English word is first recorded used by John Claudius Loudon in 1833 in ''The Gardener's Magazine'', but the concept was already long-established by then. An arboretum specializing in growing conifers is known as a pinetum. Other specialist arboreta include saliceta (willows), populeta (Populus, poplar), and querceta (oaks). Related collections include a fruticetum, from the Latin ''frutex'', meaning ''shrub'', much more often a shrubbery, and a viticetum (from the Latin ''vitis,'' meani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Botanical Garden
A botanical garden or botanic gardenThe terms ''botanic'' and ''botanical'' and ''garden'' or ''gardens'' are used more-or-less interchangeably, although the word ''botanic'' is generally reserved for the earlier, more traditional gardens, and is the more usual term in the United Kingdom. is a garden with a documented collection of living plants for the purpose of scientific research, conservation, display, and education. Typically plants are labelled with their botanical names. It may contain specialist plant collections such as cactus, cacti and other succulent plants, herb gardens, plants from particular parts of the world, and so on; there may be greenhouses, shadehouses, again with special collections such as tropical plants, alpine plants, or other exotic plants. Most are at least partly open to the public, and may offer guided tours, educational displays, art exhibitions, book rooms, open-air theatrical and musical performances, and other entertainment. Botanical gard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, or carefully controlled seed production. Most cultivars arise from purposeful human manipulation, but some originate from wild plants that have distinctive characteristics. Cultivar names are chosen according to rules of the International Code of Nomenclature for Cultivated Plants (ICNCP), and not all cultivated plants qualify as cultivars. Horticulturists generally believe the word ''cultivar''''Cultivar'' () has two meanings, as explained in ''Formal definition'': it is a classification category and a taxonomic unit within the category. When referring to a taxon, the word does not apply to an individual plant but to all plants that share the unique characteristics that define the cultivar. was coined as a term meaning "cultivated variety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dutch Elm Disease
Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was accidentally introduced into Americas, America, Europe, and New Zealand. In these regions it has devastated native populations of elms that did not have resistance to the disease. The name "Dutch elm disease" refers to its identification in 1921 and later in the Netherlands by Dutch phytopathologists Marie Beatrice Schol-Schwarz, Bea Schwarz and Christine Buisman, who both worked with professor Johanna Westerdijk. The disease affects species in the genera ''Ulmus'' and ''Zelkova''; therefore it is not specific to the Ulmus × hollandica, Dutch elm hybrid. Overview Dutch elm disease (DED) is caused by ascomycete microfungi. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite, a closely related rock, which contains a high percentage of the mineral dolomite, . ''Magnesian limestone'' is an obsolete and poorly-defined term used variously for dolomite, for limes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardwood
Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes from angiosperm trees) contrasts with softwood (which is from gymnosperm trees). Characteristics Hardwoods are produced by angiosperm trees that reproduce by flowers, and have broad leaves. Many species are deciduous. Those of temperate regions lose their leaves every autumn as temperatures fall and are dormant in the winter, but those of tropical regions may shed their leaves in response to seasonal or sporadic periods of drought. Hardwood from deciduous species, such as oak, normally shows annual growth rings, but these may be absent in some tropical hardwoods. Hardwoods have a more complex structure than softwoods and are often much slower growing as a result. The dominant feature separating "hardwoods" from softwoods is the presence o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protandrous
Sequential hermaphroditism (called dichogamy in botany) is a type of hermaphroditism that occurs in many fish, gastropods, and plants. Sequential hermaphroditism occurs when the individual changes its sex at some point in its life. In particular, a sequential hermaphrodite produces eggs (female gametes) and sperm (male gametes) at different stages in life. Species that can undergo these changes from one sex to another do so as a normal event within their reproductive cycle that is usually cued by either social structure or the achievement of a certain age or size. In animals, the different types of change are male to female (protandry or protandrous hermaphroditism), female to male (protogyny or protogynous hermaphroditism), bidirectional (serial or bidirectional hermaphroditism). Both protogynous and protandrous hermaphroditism allow the organism to switch between functional male and functional female. Bidirectional hermaphrodites have the capacity for sex change in either directi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samara (fruit)
A samara (, ) is a winged achene, a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall. A samara is a simple dry fruit, and is indehiscent (not opening along a seam). The shape of a samara enables the wind to carry the seed farther away from the tree than regular seeds would go, and is thus a form of anemochory. In some cases the seed is in the centre of the wing, as in the elms (genus ''Ulmus''), the hoptree (''Ptelea trifoliata''), and the bushwillows (genus ''Combretum''). In other cases the seed is on one side, with the wing extending to the other side, making the seed autorotate as it falls, as in the maples (genus '' Acer'') and ash trees (genus ''Fraxinus''). There are also single-wing samara such as mahogany (genus Swietenia) which have a shape that enables fluttering. Some species that normally produce paired samaras, such as ''Acer pseudoplatanus'', can also produce them in groups of three or four. File:TripleSycamoreS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particular have long propagated using the movements of humans and animals in a symbiotic relationship that is the means for seed dispersal for the one group and nutrition for the other; in fact, humans and many animals have become dependent on fruits as a source of food. Consequently, fruits account for a substantial fraction of the world's agricultural output, and some (such as the apple and the pomegranate) have acquired extensive cultural and symbolic meanings. In common language usage, "fruit" normally means the seed-associated fleshy structures (or produce) of plants that typically are sweet or sour and edible in the raw state, such as apples, bananas, grapes, lemons, oranges, and strawberries. In botanical usage, the term "fruit" also i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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