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Hairlike Pondweed
''Potamogeton trichoides'' is a species of aquatic plant known by the common name hairlike pondweed, native to Europe and western Asia where it grows in calcareous, usually nutrient-rich standing or slow-flowing water. Description Hairlike pondweed is an aquatic perennial that dies back each winter into a large number of asexually produced resting bodies called turions. There are no rhizomes. It produces slender, cylindrical or slightly compressed, branching stems usually less than a metre in length but occasionally up to 2 m. The submerged leaves are long and very narrow, typically 16–80 mm long and 0.3–1 mm wide, with the midrib occupying up to 70% of the width of the leaf near the base. They are rigid and green turning darker with age. There are no floating leaves. The inflorescence is a short spike of 3–5 flowers arising from the water on a slender peduncle. This species readily hybridizes with several other species of ''Potamogeton'' including ''P. berc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adelbert Von Chamisso
Adelbert von Chamisso (; 30 January 178121 August 1838) was a German poet and botanist, author of ''Peter Schlemihl'', a famous story about a man who sold his shadow. He was commonly known in French as Adelbert de Chamisso (or Chamissot) de Boncourt, a name referring to the family estate at Boncourt. Life The son of Louis Marie, Count of Chamisso, by his marriage to Anne Marie Gargam, Chamisso began life as Louis Charles Adélaïde de Chamissot at the ''château'' of Boncourt at Ante, in Champagne, France, the ancestral seat of his family. His name appears in several forms, one of the most common being ''Ludolf Karl Adelbert von Chamisso.''Rodolfo E.G. Pichi Sermolli. 1996. ''Authors of Scientific Names in Pteridophyta''. Royal Botanic Gardens, Kew. In 1790, the French Revolution drove his parents out of France with their seven children, and they went successively to Liège, the Hague, Würzburg, and Bayreuth, and possibly Hamburg, before settling in Berlin. There, in 179 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diederich Franz Leonhard Von Schlechtendal
Diederich Franz Leonhard von Schlechtendal (27 November 1794, Xanten – 12 October 1866, Halle) was a German botanist. He studied in Berlin, in 1819 becoming curator of the Royal Herbarium. He was a professor of botany and director of the Botanical Gardens at the Martin Luther University of Halle-Wittenberg from 1833 until his death in 1866. The genus '' Schlechtendalia'' (Asteraceae), from Brazil, Uruguay and Argentina, was named in his honor. He was editor of the botanical journal ''Linnaea'' (from 1826), and with Hugo von Mohl (1805-1872), was publisher of the ''Botanischen Zeitung'' (from 1843). He conducted important investigations of the then largely unknown flora of Mexico, carried out in conjunction with Adelbert von Chamisso (1781-1838), and based on specimens collected by Christian Julius Wilhelm Schiede (1798-1836) and Ferdinand Deppe (1794-1861). Schlechtendal was a critic of Darwinism but accepted a limited form of evolution. He advocated a form common desce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Plant
Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that grows in or near water and is either emergent, submergent, or floating. In lakes and rivers macrophytes provide cover for fish, substrate for aquatic invertebrates, produce oxygen, and act as food for some fish and wildlife. Macrophytes are primary producers and are the basis of the food web for many organisms. They have a significant effect on soil chemistry and light levels as they slow down the flow of water and capture pollutants and trap sediments. Excess sediment will settle into the benthos aided by the reduction of flow rates caused by the presence of plant stems, leaves and roots. Some plants have the capability of absorbing pollutants into their tissue. Seaweeds are multicellular marine algae and, although their ecologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turion (botany)
A turion (from Latin turio meaning "shoot") is a type of bud that is capable of growing into a complete plant. A turion may be an underground bud. Many members of the genus ''Epilobium'' are known to produce turions at or below ground level. Some aquatic plant species produce overwintering turions, especially in the genera '' Potamogeton'', ''Myriophyllum'', ''Aldrovanda'' and ''Utricularia''. These plants produce turions in response to unfavourable conditions such as decreasing day-length or reducing temperature. They are derived from modified shoot apices and are often rich in starch and sugars enabling them to act as storage organs. Although they are hardy (frost resistant), it is probable that their principal adaptation is their ability to sink to the bottom of a pond or lake when the water freezes. Because water expands anomalously at lower temperatures, water at is denser than colder water and stays at the bottom, and in this water turions over-winter before rising aga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed on the axis of a plant. The modifications can involve the length and the nature of the internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes. One can also define an inflorescence as the reproductive portion of a plant that bears a cluster of flowers in a specific pattern. The stem holding the whole inflorescence is called a peduncle. The major axis (incorrectly referred to as the main stem) above the peduncle bearing the flowers or secondary branches is called the rachis. The stalk of each flower in the inflorescence is called a pedicel. A flower that is not part of an inflorescence is called a solitary flower and its stalk is al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peduncle (botany)
In botany, a peduncle is a stalk supporting an inflorescence or a solitary flower, or, after fecundation, an infructescence or a solitary fruit. The peduncle sometimes has bracts (a type of cataphylls) at nodes. The main axis of an inflorescence above the peduncle is the rachis. There are no flowers on the peduncle but there are flowers on the rachis. When a peduncle arises from the ground level, either from a compressed aerial stem or from a subterranean stem (rhizome, tuber, bulb, corm), with few or no bracts except the part near the rachis or receptacle, it is referred to as a scape. The acorns of the pedunculate oak are borne on a long peduncle, hence the name of the tree. See also *Pedicel (botany) *Scape (botany) In botany, a scape is a peduncle arising from a subterranean or very compressed stem, with the lower internodes very long and hence few or no bracts except the part near the rachis or receptacle. Typically it takes the form of a long, leafles ... Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid (biology)
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in blending inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridisation, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization and others after it. Similar barriers exist in plants, with differences in flowering tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamogeton
''Potamogeton'' is a genus of aquatic, mostly freshwater, plants of the family Potamogetonaceae. Most are known by the common name pondweed, although many unrelated plants may be called pondweed, such as Canadian pondweed (''Elodea canadensis''). The genus name means "river neighbor", originating from the Greek ''potamos'' (river) and ''geiton'' (neighbor). Morphology ''Potamogeton'' species range from large (stems of 6 m or more) to very small (less than 10 cm). Height is strongly influenced by environmental conditions, particularly water depth. All species are technically perennial, but some species disintegrate in autumn to a large number of asexually produced resting buds called turions, which serve both as a means of overwintering and dispersal. Turions may be borne on the rhizome, on the stem, or on stolons from the rhizome. Most species, however, persist by perennial creeping rhizomes. In some cases the turions are the only means to differentiate species. The leav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamogeton Berchtoldii
''Potamogeton berchtoldii'', common name small pondweed is an aquatic plant. Description Small pondweed is a fine-leaved pondweeds with a bushy habit. It lacks a perennial rhizome and the plants die back in winter into a large number of resting buds known as turions. The stems are very slender and do not usually exceed 60 cm. The leaves are flat, usually 25–50 mm long, and less than 2 mm wide, usually with a broad band of lacunae along each side of the midrib and coloured pale green, olive green or brownish green. The open stipules and shining nodal glands can be important characters in identification. Small pondweed is similar to several other ''Potamogeton'' species, especially ''P. pusillus'', and use of a good key such as Preston (1995) is strongly recommended. It could also be confused with ''P. trichoides'' and ''P. obtusifolius''. Taxonomy Small pondweed was first named by the German botanist Franz Xaver Fieber in 1838. It is named after the 19th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamogeton Pusillus
''Potamogeton pusillus'' is a species of aquatic plant known by the common names small pondweed, lesser pondweed or least pondweed. It occurs in standing and slow-flowing freshwater habitats throughout the Northern Hemisphere. Description Lesser pondweed is a superficially grasslike herb producing a very slender, branching, somewhat compressed stem, usually less than 70 cm but occasionally up to one metre in length. Nodal glands, if present, are generally poorly developed. The leaves are narrow and linear, translucent, mid or olive green, usually 20–50 mm long × 0.8-1.4 mm wide, but rarely up to 100 mm long and 1.9 mm wide. The midrib often lacks lacunae (transparent areas either side of the midrib) either side of it, and if present, lacunae are restricted to the lower half of the leaf. There are no floating leaves. The stipules are tubular when young, but tend to split with age. Turions are produced, often in large quantities. In early autumn the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamogeton Compressus
''Potamogeton compressus'' is a species of aquatic plant known by the common names grass-wrack pondweed, flatstem pondweed and eel-grass pondweed. Description ''Potamogeton compressus'' produces a strongly flattened, robust, branching stem up to 90 cm in maximum length . It grows annually from turions and seed, producing bushy plants branching near the surface with long, rather grass-like leaves that are 85–240 mm long and 3–6 mm wide and olive-green or dark green, sometimes with a reddish tinge near the surface. Each leaf has two veins either side of the midrib and is bluntly pointed. The leaves have a rather opaque appearance compared to the transparent leaves of most pondweeds, due of the presence of fibres called sclerenchymatous strands. There are no rhizomes or floating leaves. The inflorescences are up to 6 mm long with 4-6 flowers with a short peduncle (5–20 mm long, occasionally more). The fruits are 3.1-4 x 2.1–3 mm. Grass-wrack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now called si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
