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Potamogeton Friesii
''Potamogeton friesii'', known as flat-stalked pondweed, or Fries' pondweed, is an aquatic plant in the genus ''Potamogeton''. It grows mainly in mesotrophic to eutrophic rivers, lakes, ponds and ditches, rarely in brackish water. It occurs in North America, Europe, western Asia and a few scattered locations elsewhere in Asia. Description Flat-stalked pondweed grows annually from turions and seed, producing branching plants with slender, flattened stems that are well-branched. The submerged leaves are long, rather grass-like, sessile, and translucent. The leaf tips are mucronate (i.e. with the midrib extending out of the leaf, giving a pointed appearance). Abundant turions are produced along the stem, especially in autumn as the plant disintegrates. Flat-stalked pondweed could be confused with other fine-leaved pondweeds within its range, especially ''Potamogeton obtusifolius'' but potentially also '' P. pusillus''. The combination of open stipules, rounded tips to the leave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Josef Ruprecht
Franz Josef Ruprecht (1 November 1814 – 4 April 1870) was an Austrian-born physician and botanist active in the Russian Empire, where he was known as Frants Ivanovič Ruprekht (russian: link=no, Франц Ива́нович Ру́прехт). He was born in Freiburg im Breisgau, and grew up in Prague, where he studied, and graduated as Doctor of Medicine in 1836. After a short stint in medical practice in Prague, he was appointed curator of the herbarium of the Russian Academy of Sciences in Saint Petersburg in 1839, then assistant director of the Saint Petersburg Botanical Garden between 1851 and 1855, and professor of botany in 1855 at the University of Saint Petersburg.Darwin CorrespondenceFranz Josef Ruprecht/ref> He died in Saint Petersburg in 1870. He described many new plants collected in the Russian Far East, including Alaska, then under Russian rule; examples include '' Adiantum aleuticum'', ''Lonicera maackii'', and ''Phellodendron amurense ''Phellodendron amurens ... [...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 ecological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus '' Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesotrophic Lake
The Trophic State Index (TSI) is a classification system designed to rate water bodies based on the amount of biological productivity they sustain. Although the term "trophic index" is commonly applied to lakes, any surface water body may be indexed. The TSI of a water body is rated on a scale from zero to one hundred. Under the TSI scale, water bodies may be defined as: * oligotrophic (TSI 0–40, having the least amount of biological productivity, "good" water quality); * mesotrophic (TSI 40–60, having a moderate level of biological productivity, "fair" water quality); or * eutrophic to hypereutrophic (TSI 60–100, having the highest amount of biological productivity, "poor" water quality). The quantities of nitrogen, phosphorus, and other biologically useful nutrients are the primary determinants of a water body's TSI. Nutrients such as nitrogen and phosphorus tend to be limiting resources in standing water bodies, so increased concentrations tend to result in increased p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutrophic
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytoplankton productivity". Water bodies with very low nutrient levels are termed oligotrophic and those with moderate nutrient levels are termed mesotrophic. Advanced eutrophication may also be referred to as dystrophic and hypertrophic conditions. Eutrophication can affect freshwater or salt water systems. In freshwater ecosystems it is almost always caused by excess phosphorus. In coastal waters on the other hand, the main contributing nutrient is more likely to be nitrogen, or nitrogen and phosphorus together. This depends on the location and other factors. When occurring naturally, eutrophication is a very slow process in which nutrients, especially phosphorus compounds and organic matter, accumulate in water bodies. These nutrients derive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brackish
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root '' brak''. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment (see article on shrimp farms). Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more often expressed as 0.5 to 30 parts per thousand (‰), which is a spec ... [...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] |
Sessile (botany)
In botany, sessility (meaning "sitting", used in the sense of "resting on the surface") is a characteristic of plant parts (such as flowers and leaves) that have no stalk. Plant parts can also be described as subsessile, that is, not completely sessile. A sessile flower is one that lacks a pedicel (flower stalk). A flower that is not sessile is pedicellate. For example, the genus ''Trillium'' is partitioned into two subgenera, the sessile-flowered trilliums (''Trillium'' subg. ''Sessilium'') and the pedicellate-flowered trilliums. Sessile leaves lack petioles (leaf stalks). A leaf that is not sessile is petiolate. For example, the leaves of most monocotyledons lack petioles. The term sessility is also used in mycology Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans, including as a source for tinder, traditional medicine, food, and entheogen ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamogeton Obtusifolius
''Potamogeton obtusifolius'', known as blunt-leaved pondweed, is an aquatic plant in the genus ''Potamogeton''. It grows mainly in mesotrophic to eutrophic lakes, ponds and ditches, rarely in brackish water. It occurs primarily in Central Europe, the British Isles, Fennoscandia and eastern North America. Description Blunt-leaved pondweed grows annually from turions and seed, producing branching plants with slender, flattened stems that have well-developed nodal glands (these appear as two raised bumps on the stem where the leaf attaches). The submerged leaves are long, rather grass-like, sessile, translucent leaves that are 48-85 (rarely up to 100) mm long and 1.5–3.55 mm wide and pale green, often with a very marked reddish or brownish tinge and a pink tinge along the midrib. There are 1-2 lateral veins either side of the midrib. As the name suggests, the leaf tips are rather blunt, though close inspection usually reveals a narrow point at the tip. The stipules are ... [...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 Crispus
''Potamogeton crispus'', the crisp-leaved pondweed, curly pondweed, curly-leaf pondweed or curled pondweed, is a species of aquatic plant (hydrophyte) native to Eurasia but an introduced species and often a noxious weed in North America. Description Curly-leaf pondweed is a rhizomatous perennial herb producing a flattened, branching stem up to a meter long. The submerged leaves are alternately arranged. The leaves are sessile, linear or oblong in shape, long and wide. The leaves may be bright green, olive green or (especially later in the season) fibrous and brownish and have noticeably serrated margins, a feature that distinguishes them from other pondweeds. The leaves usually have wavy edges but this is not always apparent, especially on new growth. Turions occur in leaf axils and at stem tips. The inflorescence is a short spike of flowers emerging above the water surface. It flowers from May until October. The turions of the plant develop along with the fruits and germ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamogeton Acutifolius
''Potamogeton acutifolius'' is a European species of aquatic plant in the family Potamogetonaceae, known by the common name sharp-leaved pondweed. It is threatened and declining in at least part of its range. Description Sharp-leaved pondweed grows annually from turions and seed, producing rather lax plants branching near the surface with strongly compressed stems and long, rather grass-like leaves that are 35–100 mm long and 1.5–5 mm wide and dark green, often with a marked reddish or brownish tinge. Each leaf has one vein either side of the midrib. 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). Within its range, sharp-leaved pondweed is relatively easily identified from all other pondweeds except the closely related grass-wrack pondweed ('' P. compressus'') by its combination of strongly flattened stems, sclerenchymatous strands in the le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
