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Tumbleweed
A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumbleweed is in effect the entire plant apart from the root system, but in other plants, a hollow fruit or inflorescence might detach instead. Xerophyte tumbleweed species occur most commonly in steppe and arid ecosystems, where frequent wind and the open environment permit rolling without prohibitive obstruction. Apart from its primary vascular system and roots, the tissues of the tumbleweed structure are dead; their death is functional because it is necessary for the structure to degrade gradually and fall apart so that its seeds or spores can escape during the tumbling, or germinate after the tumbleweed has come to rest in a wet location. In the latter case, many species of tumbleweed open mechanically, releasing their seeds as they swell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumbleweed In Motion
A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumbleweed is in effect the entire plant apart from the root system, but in other plants, a hollow fruit or inflorescence might detach instead. Xerophyte tumbleweed species occur most commonly in steppe and arid ecosystems, where frequent wind and the open environment permit rolling without prohibitive obstruction. Apart from its primary vascular system and roots, the tissues of the tumbleweed structure are dead; their death is functional because it is necessary for the structure to degrade gradually and fall apart so that its seeds or spores can escape during the tumbling, or germinate after the tumbleweed has come to rest in a wet location. In the latter case, many species of tumbleweed open mechanically, releasing their seeds as they swell w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumbleweed Blooming
A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumbleweed is in effect the entire plant apart from the root system, but in other plants, a hollow fruit or inflorescence might detach instead. Xerophyte tumbleweed species occur most commonly in steppe and arid ecosystems, where frequent wind and the open environment permit rolling without prohibitive obstruction. Apart from its primary vascular system and roots, the tissues of the tumbleweed structure are dead; their death is functional because it is necessary for the structure to degrade gradually and fall apart so that its seeds or spores can escape during the tumbling, or germinate after the tumbleweed has come to rest in a wet location. In the latter case, many species of tumbleweed open mechanically, releasing their seeds as they swell w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diaspore (botany)
In botany, a diaspore is a plant dispersal unit consisting of a seed or spore plus any additional tissues that assist dispersal. In some seed plants, the diaspore is a seed and fruit together, or a seed and elaiosome. In a few seed plants, the diaspore is most or all of the plant, and is known as a tumbleweed. Diaspores are common in weedy and ruderal species. Collectively, diaspores, seeds, and spores that have been modified for migration are known as ''disseminules''. Role in dispersal A diaspore of seed plus elaiosome is a common adaptation to seed dispersal by ants (myrmecochory). This is most notable in Australian and South African sclerophyll plant communities. Typically, ants carry the diaspore to their nest, where they may eat the elaiosome and discard the seed, and the seed may subsequently germinate. A diaspore of seed(s) plus fruit is common in plants dispersed by frugivores. Fruit-eating bats typically carry the diaspore to a favorite perch, where they ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind
Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hours, to global winds resulting from the difference in absorption of solar energy between the climate zones on Earth. The two main causes of large-scale atmospheric circulation are the differential heating between the equator and the poles, and the rotation of the planet ( Coriolis effect). Within the tropics and subtropics, thermal low circulations over terrain and high plateaus can drive monsoon circulations. In coastal areas the sea breeze/land breeze cycle can define local winds; in areas that have variable terrain, mountain and valley breezes can prevail. Winds are commonly classified by their spatial scale, their speed and direction, the forces that cause them, the regions in which they occur, and their effect. Winds have var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, fungi and protozoa. Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula. In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. Under favourable conditions the spore can develop into a new organism using mitotic division, producing a multicellular gametophyte, which eventually goes on to produce gametes. Two gametes fuse to form a zygote which develops into a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed Dispersal
In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, such as the wind, and living ( biotic) vectors such as birds. Seeds can be dispersed away from the parent plant individually or collectively, as well as dispersed in both space and time. The patterns of seed dispersal are determined in large part by the dispersal mechanism and this has important implications for the demographic and genetic structure of plant populations, as well as migration patterns and species interactions. There are five main modes of seed dispersal: gravity, wind, ballistic, water, and by animals. Some plants are serotinous and only disperse their seeds in response to an environmental stimulus. These modes are typically inferred based on adaptations, such as wings or fleshy fruit. However, this simplified view may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptogam
A cryptogam (scientific name Cryptogamae) is a plant (in the wide sense of the word) or a plant-like organism that reproduces by spores, without flowers or seeds. The name ''Cryptogamae'' () means "hidden reproduction", referring to the fact that no seed is produced, thus cryptogams represent the non-seed bearing plants. Other names, such as " thallophytes", "lower plants", and "spore plants" are also occasionally used. As a group, Cryptogamae are the opposite of the Phanerogamae () or Spermatophyta (), the seed plants. The best-known groups of cryptogams are algae, lichens, mosses, and ferns, but it also includes non-photosynthetic organisms traditionally classified as plants, such as fungi, slime molds, and bacteria. The classification is now deprecated in Linnaean taxonomy. At one time, the cryptogams were formally recognised as a group within the plant kingdom. In his system for classification of all known plants and animals, Carl Linnaeus (1707–1778) divided the plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selaginella
''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having spores of two types. They are sometimes included in an informal paraphyletic group called the " fern allies". '' S. moellendorffii'' is an important model organism. Its genome has been sequenced by the United States Department of Energy's Joint Genome Institute. The name ''Selaginella'' was erected by Palisot de Beauvois solely for the species ''Selaginella selaginoides'', which turns out (with the closely related ''Selaginella deflexa'') to be a clade that is sister to all other ''Selaginellas'', so any definitive subdivision of the species into separate genera leaves two taxa in ''Selaginella'', with the hundreds of other species in new or resurrected genera. ''Selaginella'' occurs mostly in the tropical regions of the world, with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puffballs
Puffballs are a type of fungus featuring a ball-shaped fruit body that bursts on impact, releasing a cloud of dust-like spores when mature. Puffballs belong to the division Basidiomycota and encompass several genera, including ''Calvatia'', ''Calbovista'' and ''Lycoperdon''. The puffballs were previously treated as a taxonomic group called the Gasteromycetes or Gasteromycetidae, but they are now known to be a polyphyletic assemblage. The distinguishing feature of all puffballs is that they do not have an open cap with spore-bearing gills. Instead, spores are produced internally, in a spheroidal fruit body called a ''gasterothecium'' (gasteroid 'stomach-like' basidiocarp). As the spores mature, they form a mass called a gleba in the centre of the fruitbody that is often of a distinctive color and texture. The basidiocarp remains closed until after the spores have been released from the basidia. Eventually, it develops an aperture, or dries, becomes brittle, and splits, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohio State University
The Ohio State University, commonly called Ohio State or OSU, is a public land-grant research university in Columbus, Ohio. A member of the University System of Ohio, it has been ranked by major institutional rankings among the best public universities in the United States. Founded in 1870 as the state's land-grant university and the ninth university in Ohio with the Morrill Act of 1862, Ohio State was originally known as the Ohio Agricultural and Mechanical College and focused on various agricultural and mechanical disciplines, but it developed into a comprehensive university under the direction of then-Governor and later U.S. president Rutherford B. Hayes, and in 1878, the Ohio General Assembly passed a law changing the name to "the Ohio State University" and broadening the scope of the university. Admission standards tightened and became greatly more selective throughout the 2000s and 2010s. Ohio State's political science department and faculty have greatly contr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruderal Species
A ruderal species is a plant species that is first to colonize disturbed lands. The disturbance may be natural for example, wildfires or avalanchesor the consequences of human activities, such as construction ( of roads, of buildings, mining, etc.) or agriculture (abandoned fields, irrigation, etc.). The term '' ruderal'' originates from the Latin word '' rudus'', meaning " rubble". Ruderal species typically dominate the disturbed area for a few years, gradually losing the competition to other native species. However, in extreme disturbance circumstances, such as when the natural topsoil is covered with a foreign substance, a single-species ruderal community may become permanently established. In addition, some ruderal invasive species may have such a competitive advantage over the native species that they, too, may permanently prevent a disturbed area from returning to its original state despite natural topsoil. Features Features contributing to a species' success as rudera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salsola Tragus Tumbleweed
''Salsola'' is a genus of the subfamily Salsoloideae in the family Amaranthaceae. The genus ''sensu stricto'' is distributed in central and southwestern Asia, North Africa, and the Mediterranean. A common name of various members of this genus and related genera is saltwort, for their salt tolerance. The genus name ''Salsola'' is from the Latin ''salsus'', meaning "salty". Description The species of ''Salsola'' are mostly subshrubs, shrubs, small trees, and rarely annuals. The leaves are mostly alternate, rarely opposite, simple, and entire. The bisexual flowers have five tepals and five stamens. The pistil ends in two stigmata. The fruit is spherical with a spiral embryo and no perisperm. Systematics The genus name ''Salsola'' was first published in 1753 by Linnaeus in ''Species Plantarum''. The type species is ''Salsola soda'' L. The genus ''Salsola'' belongs to the tribe Salsoleae ''s.s.'' of the subfamily Salsoloideae in the family Amaranthaceae. The genus was recircumscri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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