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Potamogeton × Angustifolius
''Potamogeton'' × ''angustifolius'' is a hybrid pondweed between ''Potamogeton gramineus'' and ''Potamogeton lucens'', known as long-leaved pondweed. It is widespread in rivers and lakes except where the water is very soft. Description ''Potamogeton'' × ''angustifolius'' is a hybrid between shining pondweed ''Potamogeton lucens'' and various-leaved pondweed ''Potamogeton gramineus''. It is a perennial, growing from robust rhizomes. The stems are variable: slender to robust, terete, and branching, usually reaching 1.2 m but rarely up to 2m. The submerged leaves are reduced to phyllodes at the base of the stem, but elsewhere are broad and translucent, yellowish to dark green, sometimes with a pinkish tinge. The leaves measure 50-130 × 10–25 mm on the stems and main branches, but may be much smaller on the side branches; they have 4-5 (rarely 6) veins either side of the midrib and are usually Sessile (botany), sessile but some clones may have a few Petiole (botany), petiola ... [...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] |
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] |
Terete
Terete is a term in botany used to describe a cross section that is circular, or like a distorted circle, with a single surface wrapping around it.Lichen Vocabulary, Lichens of North America Information, Sylvia and Stephen Sharnoff/ref> This is usually contrasted with cross-sections that are flattened, with a distinct upper surface that is different from the lower surface. The cross-section of a branch in a tree is somewhat round, so the branch is terete. The cross section of a normal leaf has an upper surface, and a lower surface, so the leaf is not terete. However, the fleshy leaves of succulents are sometimes terete. Fruticose lichens are terete, with a roughly circular cross section and a single wrap-around skin-like surface called the cortex, compared to foliose lichens and crustose lichens Crustose lichens are lichens that form a crust which strongly adheres to the substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllode
Phyllodes are modified petioles or leaf stems, which are leaf-like in appearance and function. In some plants, these become flattened and widened, while the leaf itself becomes reduced or vanishes altogether. Thus the phyllode comes to serve the purpose of the leaf. Some important examples are ''Euphorbia royleana'' which are cylindrical and '' Opuntia'' which are flattened. They are common in the genus ''Acacia'', especially the Australian species, at one time put in ''Acacia'' subg. ''Phyllodineae''. Sometimes, especially on younger plants, partially formed phyllodes bearing reduced leaves can be seen. The illustration (to the right) of ''Acacia suaveolens'' from ''Novae Hollandiae plantarum specimen'' shows the juvenile true leaves, together with the developing phyllodes, and the phyllodes of the mature plant. The genus, ''Daviesia'', in the family Fabaceae, is characterised in part by the plants having phyllodes. File:Acacia suaveolens 9064505997 9f14f5f117 o.jpg, ''Acacia ... [...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 to describe a fungal fruit body that is attached to or seated directly on the surface of the substrate, lacking a supporting stipe or pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transvers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petiole (botany)
In botany, the petiole () is the stalk that attaches the leaf blade to the stem, and is able to twist the leaf to face the sun. This gives a characteristic foliage arrangement to the plant. Outgrowths appearing on each side of the petiole in some species are called stipules. Leaves with a petiole are said to be petiolate, while leaves lacking a petiole are called sessile or apetiolate. Description The petiole is a stalk that attaches a leaf to the plant stem. In petiolate leaves, the leaf stalk may be long, as in the leaves of celery and rhubarb, or short. When completely absent, the blade attaches directly to the stem and is said to be sessile. Subpetiolate leaves have an extremely short petiole, and may appear sessile. The broomrape family Orobanchaceae is an example of a family in which the leaves are always sessile. In some other plant groups, such as the speedwell genus '' Veronica'', petiolate and sessile leaves may occur in different species. In the grasses (Poaceae), ... [...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] |
Potamogeton X Babingtonii F
''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 lea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jan Svatopluk Presl
Jan Svatopluk Presl (4 September 1791 – 6 April 1849) was a Czech natural scientist. He was the brother of botanist Carl Borivoj Presl (1794–1852). The Czech Botanical Society commemorated the two brothers by naming its principal publication ''Preslia'' (founded in 1914). He is the author of Czech scientific terminology of various branches of science, including the Czech chemical nomenclature Foundations of the Czech chemical nomenclature (official term in Czech: ''české chemické názvosloví'') and terminology were laid during the 1820s and 1830s. These early naming conventions fit the Czech language and, being mostly work of a singl .... He was the co-author of an important Czech taxonomic work, '' O Přirozenosti Rostlin''. Selected publications * * See also * Carl Borivoj Presl (C.Presl, 1794–1852) — Czech botanist, and younger brother of Jan Presl. * :Taxa named by Jan Svatopluk Presl References External links * Quido.cz: "Biography of Jan Svatoplu ... [...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] |
