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Stomium
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, digestion by herbivores, 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 farmer ... [...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, as well as the noli me tangere and its English translation touch-me-not. 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 made of large, thin-walled cells facilitating the propulsive release of seeds by "squirting". Pressure to expel the seeds is created by the increased concentration of a glucoside called elaterinidin in the sap of the fruit tissue's cells, leading ... [...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 (botany), bark, because they lend rigidity and do not decomposition, rot easily. Chemically, lignins are polymers made by cross-linking phenols, phenolic precursors. History Lignin was first mentioned in 1813 by the Swiss botanist Augustin Pyramus de Candolle, 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 Precipitation (chemistry), precipitated from solution using acid. He named the substance "lignine", which is derived from the Latin word ''wikt:lignum, lignum'', meaning wood. It is one of the most abundant organic polymers on Earth, exceeded only by cellulose and chitin. Lignin constitutes 30% of terrestrial non-fossil organic carbon on Earth, and 20 to 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tension (mechanics)
Tension is the pulling or stretching force transmitted axially along an object such as a string, rope, chain, rod, truss member, or other object, so as to stretch or pull apart the object. In terms of force, it is the opposite of ''compression''. Tension might also be described as the action-reaction pair of forces acting at each end of an object. 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 the objects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Septum
In biology, a septum (Latin language, Latin for ''something that encloses''; septa) is a wall, dividing a Body cavity, 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 Pulmonary alveolus, 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 * Septum of the penis, Penile septum, a fibrous w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theca
In biology, a theca (: 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 the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locule
A locule (: locules) or loculus (; : loculi) 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), , , or . 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. In ascomycetous fungi, locules are chambers within the hymenium The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in oth ... in which the perithecia develop. References Plant anatomy Plant ... [...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 and bumblebees, 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 pri ... [...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 the 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 cort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (botany)
In botany, an operculum (: opercula) or calyptra () is a cap-like structure in some flowering plants, mosses, and fungus, 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 op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hibiscus Trionum
''Hibiscus trionum'', commonly called flower-of-an-hour, bladder hibiscus, bladder ketmia, bladder weed, puarangi 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 self-pollination. Duri ... [...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 areasEncyclopædia 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 rootstock, of the family (biology), family Nitrariaceae, usually growing in saline soils in Desert#Classification, temperate desert and Mediterranean climate, Mediterranean regions. Its common English-language name came about because of a resemblance to rue (to which it is not related). Its seeds contain a high concentration (at least 5.9% by weight) of diverse beta-carboline alkaloids. It has deep roots and a strong smell, finely divided leaves, white flowers rich in alkaloids, and small Capsule (fruit), seed capsules containing numerous dark, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
