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Fen Pondweed
''Potamogeton coloratus'', the fen pondweed, is an aquatic plant in the genus ''Potamogeton''. It is found in shallow peaty calcareous lakes, ponds and ditches, commonly associated with lowland fens. Description Fen pondweed grows from perennial, creeping rhizomes. The leaves are broad, thin and translucent with noticeable reticulate veining. Both floating and submerged leaves are produced but the difference between these is often rather indistinct, rather than the marked dimorphism seen in other pondweeds. Often, the leaves of fen pondweed are simply longer and narrower lower down the stem and shorter and rounder towards its apex; the leaves towards the apex of the stem may be floating but often grow just below the surface, giving the plant a distinctive 'drowned' appearance, as though water levels have recently risen. Submerged leaves are 70–175 mm long and 10–30 mm wide. All leaves have the stalk shorter than the blade, and the submerged leaves are almost sessil ... [...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 Natans
''Potamogeton natans'', commonly known as broad-leaved pondweed, floating pondweed, or floating-leaf pondweed, is an aquatic species in the genus ''Potamogeton'' native to quiet or slow-flowing freshwater habitats throughout the Holarctic Kingdom. Description It produces both floating and submersed leaves on the same plant. The floating leaves are ovate to oblong-ovate and almost always cordate at the base. They are dark green, leathery, opaque, with translucent longitudinal veins. They are 5 to 10 cm long, pointed at the tips, and rounded at the base. The stipules are 4 to 17 cm long. The submerged grass-like structures are called phyllodes, are actually modified leaf stalks. The stems are cylindrical, without many branches, and grow from 1 to 2 metres. The main difference between this species and other pondweeds is a discoloured flexible joint just below the top of the long leaf stalk. The flower spikes are dense, and cylindrical. They are 5 to 10 cm lon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamogeton Polygonifolius
''Potamogeton polygonifolius'' or bog pondweed, is an aquatic plant. It is found in shallow, nutrient-poor, usually acid standing or running water, bogs, fens and occasionally ditches. Description Bog pondweed is a perennial, growing from creeping rhizomes. The stems are up to 0.7 m long, terete and unbranched. The submerged leaves are long (60–160 mm) and fairly narrow (2.5–24 mm), delicate and translucent with long (14–80 mm) petioles, tending to decay rather early in the season, typically once the floating leaves appear. The floating leaves are opaque, 40-105 x 15–70 mm, usually brownish or dark green in colour with a pink tint when young, with inconspicuous secondary veins. There are no turions. The inflorescences are up to 42 mm long and produce numerous small greenish flowers. The fruits are 1.9-2.6 mm x 1.4-1.9 mm, larger than ''P. coloratus'' but smaller than ''P. natans''. Bog pondweed occurs both as terrestrial plants in s ... [...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] |
Potamogeton Lucens
''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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stipule
In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many species they may be inconspicuous —or sometimes entirely absent, and the leaf is then termed ''exstipulate''. (In some older botanical writing, the term "stipule" was used more generally to refer to any small leaves or leaf-parts, notably prophylls.) The word ''stipule'' was coined by Linnaeus''Concise English Dictionary'' Wordsworth Editions Ltd. 1994, from Latin ''stipula'', straw, stalk. Types of stipules General characteristics The position of stipules on a plant varies widely from species to species, though they are often located near the base of a leaf. Stipules are most common on dicotyledons, where they appear in pairs alongside each leaf. Some monocotyledon plants display stipule-like structures, but only display one per leaf ... [...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 Gramineus
''Potamogeton gramineus'' is a species of aquatic plant known by the common name various-leaved pondweed, variableleaf pondweed, grass-leaved pondweed or grassy pondweed, native to the northern hemisphere where it grows in shallow, clean water. Description This is an aquatic perennial growing from a creeping rhizome that anchors in wet substrate. It produces thin, cylindrical, heavily branching stems usually less than a metre in length. The submerged leaves are sessile, relatively narrow, typically 40–90 mm long and 5–12 mm wide along the main stem but smaller on the side branches. They are translucent and pale green with a white midrib, and finely toothed. Floating leaves are more oval in shape, 20–70 mm long by 7–34 mm wide, and borne on long petioles. The inflorescence is a short spike of many flowers arising from the water on a stout peduncle. This species readily hybridizes with many other species of ''Potamogeton''. Hybrids have been recorded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jens Wilken Hornemann
Jens Wilken Hornemann (6 March 1770 – 30 July 1841) was a Danish botanist. Biography He was a lecturer at the University of Copenhagen Botanical Garden from 1801. After the death of Martin Vahl in 1804, the task of publishing the Flora Danica was given to Hornemann, who subsequently issued fasc. 22-39 (1801–1840) with a total of 1080 plates. J.W. Hornemann was professor of botany at the University of Copenhagen from 1808 and director of the Botanic Garden (from 1817). In 1815, he was elected a corresponding member of the Royal Swedish Academy of Sciences, and in 1816, his status was changed to that of foreign member. Honours Several plant genera have been named in his honour, however for reasons of taxonomy and nomenclature all names are today synonyms. ''Hornemannia'' Willd. (1809), once placed in Scrophulariaceae, contained on two species, both of which are now referred to other genera (one to the genus ''Mazus'' Lour. (1790) and the other to ''Lindernia'' All. (1766)). Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stoneworts
Charales is an order of freshwater green algae in the division Charophyta, class Charophyceae, commonly known as stoneworts. Depending on the treatment of the genus ''Nitellopsis'', living (extant) species are placed into either one family (Characeae) or two (Characeae and Feistiellaceae). Further families are used for fossil members of the order. Linnaeus established the genus '' Chara'' in 1753. Taxonomy The higher level classification of green algae was unsettled . AlgaeBase places Charales within the class Charophyceae and its circumscription of the division Charophyta. Families The number of families and their division into genera varies. , AlgaeBase accepts two families containing some extant species and four families containing only fossil species: *Characeae S.F.Gray * Feistiellaceae Schudack *† Aclistocharaceae X.G.Zhou (may be included in Characeae) *† Atopocharaceae R.E.Peck (may be included in Clavatoraceae) *† Clavatoraceae Pia *† Porocharaceae Grambast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bladderworts
''Utricularia'', commonly and collectively called the bladderworts, is a genus of carnivorous plants consisting of approximately 233 species (precise counts differ based on classification opinions; a 2001 publication lists 215 species).Salmon, Bruce (2001). ''Carnivorous Plants of New Zealand''. Ecosphere Publications. They occur in fresh water and wet soil as terrestrial or aquatic species across every continent except Antarctica. ''Utricularia'' are cultivated for their flowers, which are often compared with those of snapdragons and orchids, especially amongst carnivorous plant enthusiasts. All ''Utricularia'' are carnivorous and capture small organisms by means of bladder-like traps. Terrestrial species tend to have tiny traps that feed on minute prey such as protozoa and rotifers swimming in water-saturated soil. The traps can range in size from .Taylor, Peter. (1989). ''The genus Utricularia - a taxonomic monograph''. Kew Bulletin Additional Series XIV: London. Aquatic spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juncus Subnodulosus
''Juncus subnodulosus'', the blunt-flowered rush, is a species of rush. It natively occurs from the Mediterranean region across temperate Europe, but it does not range far into Scandinavia. Introduced populations exist in New Zealand and North America. This species is an important associate within the anthropogenic ''Juncus subnodulosus-Cirsium palustre'' fen-meadow ecosystem, an important habitat type of Western Europe. ''J. subnodulosus'' is particularly prevalent within the disturbed ridges of this type of fen-meadow A fen-meadow is a type of peatland, common in North America and Europe, that receives water from precipitation and groundwater. Habitat The continuous flow of mineral-rich and nutrient-poor acidic groundwater through fen-meadow topsoil fosters ....Perring ''et al.'' (1964), Hogan (2009) Footnotes References * (1964): ''A flora of Cambridgeshire''. Cambridge University Press, Cambridge, United Kingdom. * (2009)Marsh Thistle: ''Cirsium palustre''at G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
