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Thesium Humifusum
''Thesium humifusum'' is a species of hemiparasitic flowering plant in the family Santalaceae found in western Europe and north-western Africa, known as bastard-toadflax. Distribution Within continental Europe, ''Thesium humifusum'' is found throughout France, Spain and Italy. In the Netherlands, it is very rare, being now restricted to a single dune system near Katwijk aan Zee. In Belgium, it can be found in coastal dunes in Flanders, and perhaps one site in Wallonia. It is the only species of ''Thesium'' in Great Britain, and is there considered 'scarce'. ''Thesium humifusum'' may also occur in parts of North Africa. Ecology ''Thesium humifusum'' is a hemiparasitic plant that steals nutrients from hedge bedstraw (''Galium album'') or lady's bedstraw (''Galium verum''). Although it can be abundant in appropriate habitats, its low growth habit and inconspicuous flowers mean that it is often overlooked. In Great Britain, it is restricted to downlands over chalk or oolitic limest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Augustin Pyramus De Candolle
Augustin Pyramus (or Pyrame) de Candolle (, , ; 4 February 17789 September 1841) was a Swiss botanist. René Louiche Desfontaines launched de Candolle's botanical career by recommending him at a herbarium. Within a couple of years de Candolle had established a new genus, and he went on to document hundreds of plant families and create a new natural plant classification system. Although de Candolle's main focus was botany, he also contributed to related fields such as phytogeography, agronomy, paleontology, medical botany, and economic botany. De Candolle originated the idea of "Nature's war", which influenced Charles Darwin and the principle of natural selection. de Candolle recognized that multiple species may develop similar characteristics that did not appear in a common evolutionary ancestor; a phenomenon now known as convergent evolution. During his work with plants, de Candolle noticed that plant leaf movements follow a near-24-hour cycle in constant light, suggestin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitic Plant
A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All parasitic plants develop a specialized organ called the haustorium, which penetrates the host plant, connecting them to the host vasculature – either the xylem, phloem, or both. For example, plants like ''Striga'' or ''Rhinanthus'' connect only to the xylem, via xylem bridges (xylem-feeding). Alternately, plants like ''Cuscuta'' and some members of ''Orobanche'' connect to both the xylem and phloem of the host. This provides them with the ability to extract water and nutrients from the host. Parasitic plants are classified depending on the location where the parasitic plant latches onto the host (root or stem), the amount of nutrients it requires, and their photosynthetic capability. Some parasitic plants can locate their host plants by detecting volatile chemicals in the air or soil given ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovary (botany)
In the flowering plants, an ovary is a part of the female reproductive organ of the flower or gynoecium. Specifically, it is the part of the pistil which holds the ovule(s) and is located above or below or at the point of connection with the base of the petals and sepals. The pistil may be made up of one carpel or of several fused carpels (e.g. dicarpel or tricarpel), and therefore the ovary can contain part of one carpel or parts of several fused carpels. Above the ovary is the style and the stigma, which is where the pollen lands and germinates to grow down through the style to the ovary, and, for each individual pollen grain, to fertilize one individual ovule. Some wind pollinated flowers have much reduced and modified ovaries. Fruits A fruit is the mature, ripened ovary of a flower following double fertilization in an angiosperm. Because gymnosperms do not have an ovary but reproduce through double fertilization of unprotected ovules, they produce naked seeds that do not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stamen
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament and an anther which contains ''sporangium, microsporangia''. Most commonly anthers are two-lobed and are attached to the filament either at the base or in the middle area of the anther. The sterile tissue between the lobes is called the connective, an extension of the filament containing conducting strands. It can be seen as an extension on the dorsal side of the anther. A pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The stamens in a flower are collectively called the androecium. The androecium can consist of as few as one-half stamen (i.e. a single locule) as in ''Canna (plant), Canna'' species or as many as 3,482 stamens which have been counted in the saguaro (''Carnegiea gigantea'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tepal
A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very similar appearance), as in ''Magnolia'', or because, although it is possible to distinguish an outer whorl of sepals from an inner whorl of petals, the sepals and petals have similar appearance to one another (as in ''Lilium''). The term was first proposed by Augustin Pyramus de Candolle in 1827 and was constructed by analogy with the terms "petal" and "sepal". (De Candolle used the term ''perigonium'' or ''perigone'' for the tepals collectively; today, this term is used as a synonym for ''perianth''.) p. 39. Origin Undifferentiated tepals are believed to be the ancestral condition in flowering plants. For example, '' Amborella'', which is thought to have separated earliest in the evolution of flowering plants, has flowers with undiffer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dune
A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, flat regions covered with wind-swept sand or dunes with little or no vegetation are called ''ergs'' or ''sand seas''. Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have a shorter ''slip face'' in the lee side. The valley or trough between dunes is called a ''dune slack''. Dunes are most common in desert environments, where the lack of moisture hinders the growth of vegetation that would otherwise interfere with the development of dunes. However, sand deposits are not restricted to deserts, and dunes are also found along sea shores, along streams in semiarid climates, in areas of glacial outwash, and in other areas where poorly cemented sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Records Centre
The Biological Records Centre (BRC) established in 1964, is a national focus in the UK for terrestrial and fresh water species recording. The term "biological records centre" is also used in the context of local centres, now frequently referred to as "local environmental records centres" (LERCs). History The Biological Records Centre (BRC) was set up in 1964 by the Nature Conservancy (UK) at its recently opened Monks Wood Experimental Station near Huntingdon. BRC developed from the Atlas of the British Flora project of the Botanical Society of the British Isles (BSBI) to map the distribution of British (and Irish) flowering plants, which had established basic principles for biological recording in the UK. The former BSBI project leader, Franklyn Perring, established BRC with the project's original data and data processing equipment. Function As part of the UK Centre for Ecology & Hydrology (UKCEH), BRC provides a focus for the collation, management, dissemination and interpret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oolitic Limestone
Oolite or oölite (''egg stone'') is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. The name derives from the Ancient Greek word for egg (ᾠόν). Strictly, oolites consist of ooids of diameter 0.25–2 millimetres; rocks composed of ooids larger than 2 mm are called pisolites. The term ''oolith'' can refer to oolite or individual ooids. Composition Ooids are most commonly composed of calcium carbonate (calcite or aragonite), but can be composed of phosphate, clays, chert, dolomite or iron minerals, including hematite. Dolomitic and chert ooids are most likely the result of the replacement of the original texture in limestone. Oolitic hematite occurs at Red Mountain near Birmingham, Alabama, along with oolitic limestone. They are usually formed in warm, supersaturated, shallow, highly agitated marine water intertidal environments, though some are formed in inland lakes. The mechanism of formation starts with a small fragment of se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalk
Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Chalk is common throughout Western Europe, where deposits underlie parts of France, and steep cliffs are often seen where they meet the sea in places such as the Dover cliffs on the Kent coast of the English Channel. Chalk is mined for use in industry, such as for quicklime, bricks and builder's putty, and in agriculture, for raising pH in soils with high acidity. It is also used for " blackboard chalk" for writing and drawing on various types of surfaces, although these can also be manufactured from other carbonate-based minerals, or gypsum. Description Chalk is a fine-textured, earthy type of limestone distinguished by its light color, softness, and high porosity. It is composed mostly of tiny fragments of the calcite shells or skeletons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downland
Downland, chalkland, chalk downs or just downs are areas of open chalk hills, such as the North Downs. This term is used to describe the characteristic landscape in southern England where chalk is exposed at the surface. The name "downs" is derived from the Old English word dun, meaning "hill". Distribution The largest area of downland in southern England is formed by Salisbury Plain, mainly in Wiltshire. To the southwest, downlands continue via Cranborne Chase into Dorset as the Dorset Downs and southwards through Hampshire as the Hampshire Downs onto the Isle of Wight. To the northeast, downlands continue along the Berkshire Downs and Chiltern Hills through parts of Berkshire, Oxfordshire, Buckinghamshire, Hertfordshire, Bedfordshire and into Cambridgeshire. To the east downlands are found north of the Weald in Surrey, Kent and part of Greater London, forming the North Downs. To the southeast the downlands continue into West Sussex and East Sussex as the South Downs. Similar cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galium Verum
''Galium verum'' (lady's bedstraw or yellow bedstraw) is a herbaceous perennial plant of the family Rubiaceae. It is widespread across most of Europe, North Africa, and temperate Asia from Israel, Lebanon and Turkey to Japan and Kamchatka. It is naturalized in Tasmania, New Zealand, Canada, and the northern half of the United States. It is considered a noxious weed in some places. ''Galium verum'' is a low scrambling plant, with the stems growing to long, frequently rooting where they touch the ground. The leaves are long and broad, shiny dark green, hairy underneath, borne in whorls of 8–12. The flowers are in diameter, yellow, and produced in dense clusters. This species is sometimes confused with ''Galium odoratum'', a species with traditional culinary uses. Uses In medieval Europe, the dried plants were used to stuff mattresses, as the coumarin scent of the plants acts as a flea repellant. The flowers were also used to coagulate milk in cheese manufacture (which gives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galium Album
''Galium album'', the white bedstraw or hedge bedstraw, is a herbaceous annual plant of the family Rubiaceae. Description The stems can grow to at least 150 cm and are more or less erect with ascending branches. The stem is square in section with slight flanges. The plant is relatively hairless with shiny leaves and stem. Flowers are white or yellowish.Clapham, A. R., Tutin, T. G. and Warburg, E. F. (1987). ''Excursion Flora of the British Isles.'' Cambridge: Cambridge University Press. . p. 302. The fruit are hairless.Michalková, Eleonóra. 1993. Biología, Bot. (Bratislava) 48(1): 48 Habitat and distribution ''Galium album'' is widespread over much of Europe, being native to a large region from Britain to Morocco, east to Turkey and Western Siberia. It is naturalized in Ireland, Scandinavia, Greenland and South Australia. It is found in pastures, grassy banks, etc., especially on dry calcareous soils. In Britain, ''G. album'' is local in lowland England, rare in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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