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Dehiscence (botany)
Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part; structures that open in this way are said to be dehiscent. Structures that do not open in this way are called indehiscent, and rely on other mechanisms such as decay or predation to release the contents. A similar process to dehiscence occurs in some flower buds (e.g., ''Platycodon'', ''Fuchsia''), but this is rarely referred to as dehiscence unless circumscissile dehiscence is involved; anthesis is the usual term for the opening of flowers. Dehiscence may or may not involve the loss of a structure through the process of abscission. The lost structures are said to be caducous. Association with crop breeding Manipulation of dehiscence can improve crop yield since a trait that causes seed dispersal is a disadvantage for farmers whose goal is to collect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecballium
''Ecballium'' is a genus of flowering plants in the family Cucurbitaceae containing a single species, ''Ecballium elaterium'', also called the squirting cucumber or exploding cucumber (not the same plant as '' Cyclanthera brachystachya''). Its unusual common name derives from the ripe fruit squirting a stream of mucilaginous liquid containing its seeds as a means of seed dispersal, an example of rapid plant movement. Distribution ''E. elaterium'' is native to Europe, northern Africa, and temperate areas of Asia, and is considered an invasive species. It is grown as an ornamental plant elsewhere, and in some places it has naturalized. Seed dispersal The tissue in the fruit of the ''Ecballium elaterium'' that surrounds the seeds is thin walled, facilitating the propulsive release of seeds by "squirting". Pressure to expel the seeds is created by the increased concentration of glucoside and elaterinidin in low volumes of cytoplasm, leading to an osmotic pressure of up to 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignification
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. History Lignin was first mentioned in 1813 by the Swiss botanist A. P. de Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid. He named the substance “lignine”, which is derived from the Latin word ''lignum'', meaning wood. It is one of the most abundant organic polymers on Earth, exceeded only by cellulose. Lignin constitutes 30% of non-fossil organic carbon on Earth, and 20 to 35% of the dry mass of wood. Lignin is present in red algae, which suggest that the common ancestor of plants and red algae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tension (mechanics)
In physics, tension is described as the pulling force transmitted axially by the means of a string, a rope, chain, or similar object, or by each end of a rod, truss member, or similar three-dimensional object; tension might also be described as the action-reaction pair of forces acting at each end of said elements. Tension could be the opposite of compression. At the atomic level, when atoms or molecules are pulled apart from each other and gain potential energy with a restoring force still existing, the restoring force might create what is also called tension. Each end of a string or rod under such tension could pull on the object it is attached to, in order to restore the string/rod to its relaxed length. Tension (as a transmitted force, as an action-reaction pair of forces, or as a restoring force) is measured in newtons in the International System of Units (or pounds-force in Imperial units). The ends of a string or other object transmitting tension will exert forces on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Septum
In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Human anatomy * Interatrial septum, the wall of tissue that is a sectional part of the left and right atria of the heart * Interventricular septum, the wall separating the left and right ventricles of the heart * Lingual septum, a vertical layer of fibrous tissue that separates the halves of the tongue. * Nasal septum: the cartilage wall separating the nostrils of the nose * Alveolar septum: the thin wall which separates the alveoli from each other in the lungs * Orbital septum, a palpebral ligament in the upper and lower eyelids * Septum pellucidum or septum lucidum, a thin structure separating two fluid pockets in the brain * Uterine septum, a malformation of the uterus * Vaginal septum, a lateral or transverse partition inside the vagina * Interm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theca
In biology, a theca (plural thecae) is a sheath or a covering. Botany In botany, the theca is related to plant's flower anatomy. The theca of an angiosperm consists of a pair of microsporangia that are adjacent to each other and share a common area of dehiscence called the stomium. Larry Hufford, "The origin and early evolution of angiosperm stamens" i''The Anther: form, function, and phylogeny'' William G. D'Arcy and Richard C. Keating (editors), Cambridge University Press, 1996, 351pp, p.60, (from Google Books) Any part of a microsporophyll that bears microsporangia is called an anther. Most anthers are formed on the apex of a filament. An anther and its filament together form a typical (or filantherous) stamen, part of the male floral organ. The typical anther is bilocular, i.e. it consists of two thecae. Each theca contains two microsporangia, also known as pollen sacs. The microsporangia produce the microspores, which for seed plants are known as pollen grains. If ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locule
A locule (plural locules) or loculus (plural loculi) (meaning "little place" in Latin) is a small cavity or compartment within an organ or part of an organism (animal, plant, or fungus). In angiosperms (flowering plants), the term ''locule'' usually refers to a chamber within an ovary (gynoecium or carpel) of the flower and fruits. Depending on the number of locules in the ovary, fruits can be classified as ''uni-locular'' (unilocular), ''bi-locular'', ''tri-locular'' or ''multi-locular''. The number of locules present in a gynoecium may be equal to or less than the number of carpels. The locules contain the ovules or seeds. The term may also refer to chambers within anthers containing pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop .... In Ascomycete fungi, locules are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buzz Pollination
Buzz pollination or sonication is a technique used by some bees, such as solitary bees to release pollen which is more or less firmly held by the anthers. The anthers of buzz-pollinated plant species are typically tubular, with an opening at only one end, and the pollen inside is smooth-grained and firmly attached. With self-fertile plants such as tomatoes, wind may be sufficient to shake loose the pollen through pores in the anther and accomplish pollination. Visits by bees may also shake loose some pollen, but more efficient pollination of those plants is accomplished by a few insect species who specialize in sonication or buzz pollination. In order to release the pollen, solitary bees are able to grab onto the flower and move their flight muscles rapidly, causing the flower and anthers to vibrate, dislodging pollen. Pollination involving vibrations is called buzz pollination. Honeybees cannot perform buzz pollination. About 9% of the flowers of the world are primarily pollin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxogastria
Myxogastria/Myxogastrea (myxogastrids, ICZN) or Myxomycetes ( ICN), is a class of slime molds that contains 5 orders, 14 families, 62 genera, and 888 species. They are colloquially known as the ''plasmodial'' or ''acellular'' slime moulds. All species pass through several, very different morphologic phases, such as microscopic individual cells, slimy amorphous organisms visible with the naked eye and conspicuously shaped fruit bodies. Although they are monocellular, they can reach immense widths and weights: in extreme cases they can be up to across and weigh up to . The class Myxogastria is distributed worldwide, but it is more common in temperate regions where it has a higher biodiversity than in polar regions, the subtropics or tropics. They are mainly found in open forests, but also in extreme regions such as deserts, under snow blankets or underwater. They also occur on the bark of trees, sometimes high in the canopy. These are known as corticolous m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (botany)
In botany, an operculum () or calyptra () is a cap-like structure in some flowering plants, mosses, and fungi. It is a covering, hood or lid, describing a feature in plant morphology. Flowering plants In flowering plants, the operculum, also known as a calyptra, is the cap-like covering or "lid" of the flower or fruit that detaches at maturity. The operculum is formed by the fusion of sepals and/or petals and is usually shed as a single structure as the flower or fruit matures. The name is also used for the capping tissue of roots, the root cap. In eucalypts, (including ''Eucalyptus'' and ''Corymbia'' but not ''Angophora'') there may be two opercula - an outer operculum formed by the fusion of the united sepals and an inner operculum formed by the fusion of the sepals. In that case, the outer operculum is shed early in the development of the bud leaving a scar around the bud. In those species that lack an outer operculum, there is no bud scar. The inner operculum is shed just ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hibiscus Trionum
''Hibiscus trionum'', commonly called flower-of-an-hour, bladder hibiscus, bladder ketmia, bladder weed, modesty, puarangi, shoofly, and venice mallow, is an annual plant native to the Old World tropics and subtropics. It has spread throughout southern Europe both as a weed and cultivated as a garden plant. It has been introduced to the United States as an ornamental where it has become naturalized as a weed of cropland and vacant land, particularly on disturbed ground. Description The plant grows to a height of , sometimes exceeding , and has white or yellow flowers with a purple centre. In the deeply pigmented centre of the flower, the surface features striations, which have been the subject of controversy about whether they act as a diffraction grating, creating iridescence. The pollinated but unripe seedpods look like oriental paper lanterns, less than across, pale green with purple highlights. The flowers of ''Hibiscus trionum'' can set seed via both outcrossing and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peganum Harmala
''Peganum harmala'', commonly called wild rue, Syrian rue, African rue, esfand or espand,Mahmoud OmidsalaEsfand: a common weed found in Persia, Central Asia, and the adjacent areasEncyclopedia Iranica Vol. VIII, Fasc. 6, pp. 583–584. Originally published: 15 December 1998. Online version last updated 19 January 2012 or harmel, (among other similar pronunciations and spellings) is a perennial, herbaceous plant, with a woody underground root-stock, of the family Nitrariaceae, usually growing in saline soils in temperate desert and Mediterranean regions. Its common English-language name came about because of a resemblance to rue (to which it is not related). Because eating it can cause livestock to sicken or die, it is considered a noxious weed in a number of countries. It has become an invasive species in some regions of the western United States. The plant is popular in Middle Eastern and north African folk medicine. The alkaloids contained in the plant, including the seeds, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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