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Zizania Texana
''Zizania texana'' is a rare species of grass known by the common name Texas wild rice. It is endemic to Texas, where it is found only on the upper San Marcos River in Hays County. It is threatened by the loss and degradation of its habitat. It is a federally listed endangered species of the United States. This grass, a member of the same genus as commercially sold wild rice, is an aquatic plant that grows in the water with only its stem tips rising above the surface. It grows 1 to 2 meters long but the stems have been known to reach five meters in length. The ribbon-like leaves are up to a meter in length. The inflorescence is a panicle up to 31 centimeters long by 10 wide. The male spikelet is somewhat oval in shape and the female is lance-shaped with a long awn which may be a few centimeters in length.''Ziza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Marcos Springs
San Marcos Springs is the second largest natural cluster of springs in Texas. The springs are located in the city of San Marcos, Texas, about 30 miles (48 km) southwest of Austin and 46 miles (74 km) northeast of San Antonio. Although Spring Lake is highly protected, it is accessible to visitors through the Meadows Center for Water and the Environment, a program of Texas State University, which offers glass-bottom boat tours among other opportunities to explore and learn about the ecosystem. Geology The San Marcos Springs is an area of artesian outflow from the Edwards Aquifer along the Balcones Escarpment. More than 200 springs flow from three large fissures and other smaller openings in the rock. The springs provide most of the water for the San Marcos River, which flows southward from the springs' location. The springs have never been known to stop flowing. The average flow is 152 ft³/s (4,300 liters/s); the lowest recorded flow of 46 ft³/s (1, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Flora Of Texas
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example ''Cytisus aeolicus'' is an endemite of the Italian flora. ''Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oryzoideae
Oryzoideae ( syn. Ehrhartoideae) is a subfamily of the true grass family Poaceae. It has around 120 species in 19 genera, notably including the major cereal crop rice. Within the grasses, this subfamily is one of three belonging to the species-rich BOP clade, which all use C3 photosynthesis; it is the basal lineage of the clade. It contains four tribes and one genus of unclear position (incertae sedis): '' Suddia'' (thought likely to be in the tribe Phyllorachideae). Phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ... analyses have resolved the branching order of these clades within the subfamily: References Poaceae subfamilies Taxa named by Carl Sigismund Kunth {{Poaceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tiller (botany)
A tiller is a shoot that arises from the base of a grass plant. The term refers to all shoots that grow after the initial parent shoot grows from a seed. Tillers are segmented, each segment possessing its own two-part leaf. They are involved in vegetative propagation and, in some cases, also seed production. "Tillering" refers to the production of side shoots and is a property possessed by many species in the grass family. This enables them to produce multiple stems (tillers) starting from the initial single seedling. This ensures the formation of dense tufts and multiple seed heads. Tillering rates are heavily influenced by soil water quantity. When soil moisture is low, grasses tend to develop more sparse and deep root systems (as opposed to dense, lateral systems). Thus, in dry soils, tillering is inhibited: the lateral nature of tillering is not supported by lateral root growth. See also *Crown (botany) The crown of a plant refers to the total of an individual plant's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Introduced Species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are considered naturalized. The process of human-caused introduction is distinguished from biological colonization, in which species spread to new areas through "natural" (non-human) means such as storms and rafting. The Latin expression neobiota captures the characteristic that these species are ''new'' biota to their environment in terms of established biological network (e.g. food web) relationships. Neobiota can further be divided into neozoa (also: neozoons, sing. neozoon, i.e. animals) and n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nutria
The nutria (''Myocastor coypus''), also known as the coypu, is a large, herbivorous, semiaquatic rodent. Classified for a long time as the only member of the family Myocastoridae, ''Myocastor'' is now included within Echimyidae, the family of the spiny rats. The nutria lives in burrows alongside stretches of water, and feeds on river plant stems. Originally native to subtropical and temperate South America, it has since been introduced to North America, Europe, Asia, and Africa, primarily by fur farmers. Although it is still hunted and trapped for its fur in some regions, its destructive burrowing and feeding habits often bring it into conflict with humans, and it is considered an invasive species. Nutria also transmit various diseases to humans and animals mainly through water contamination. Etymology The genus name ''Myocastor'' derives from the two Ancient Greek words (), meaning "rat, mouse", and (), meaning "beaver". Literally, therefore, the name ''Myocastor'' mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbidity
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can contain suspended solid matter consisting of particles of many different sizes. While some suspended material will be large enough and heavy enough to settle rapidly to the bottom of the container if a liquid sample is left to stand (the settable solids), very small particles will settle only very slowly or not at all if the sample is regularly agitated or the particles are colloidal. These small solid particles cause the liquid to appear turbid. Turbidity (or haze) is also applied to transparent solids such as glass or plastic. In plastic production, haze is defined as the percentage of light that is deflected more than 2.5° from the incoming light direction. Causes and effects Turbidity in open water may be caused by growth of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edwards Aquifer
The Edwards Aquifer is one of the most prolific artesian aquifers in the world. Located on the eastern edge of the Edwards Plateau in the U.S. state of Texas, it is the source of drinking water for two million people, and is the primary water supply for agriculture and industry in the aquifer's region. Additionally, the Edwards Aquifer feeds the Comal and San Marcos springs, provides springflow for recreational and downstream uses in the Nueces, San Antonio, Guadalupe, and San Marcos river basins, and is home to several unique and endangered species. Basin characteristics Geography Located in South Central Texas, the Edwards Aquifer encompasses an area of approximately that extends into parts of 11 counties. The aquifer's boundaries begin at the groundwater divide in Kinney County, East of Brackettville, and extend Eastward through the San Antonio area and then Northeast where the aquifer boundary ends at the Leon River in Bell County.Tremallo, Robin; Hamiton, Mark; Johnson ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring (hydrosphere)
A spring is a point of exit at which groundwater from an aquifer flows out on top of Earth's crust (pedosphere) and becomes surface water. It is a component of the hydrosphere. Springs have long been important for humans as a source of fresh water, especially in arid regions which have relatively little annual rainfall. Springs are driven out onto the surface by various natural forces, such as gravity and hydrostatic pressure. Their yield varies widely from a volumetric flow rate of nearly zero to more than for the biggest springs. Formation Springs are formed when groundwater flows onto the surface. This typically happens when the groundwater table reaches above the surface level. Springs may also be formed as a result of karst topography, aquifers, or volcanic activity. Springs also have been observed on the ocean floor, spewing hot water directly into the ocean. Springs formed as a result of karst topography create karst springs, in which ground water travel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas State University
Texas State University is a public research university in San Marcos, Texas. Since its establishment in 1899, the university has grown to the second largest university in the Greater Austin metropolitan area and the fifth largest university in the state of Texas. Texas State University reached a record enrollment of 38,808 students in the 2016 fall semester, continuing a trend of enrollment growth over several years. The university offers more than 200 degree options from its ten colleges. Texas State is classified among "R2: Doctoral Universities – High research activity" and an emerging research university by the State of Texas. The university is accredited by the Southern Association of Colleges and Schools (SACS). Faculty from the various colleges have consistently been granted Fulbright Scholarships resulting in Texas State's being recognized as one of the top producing universities of Fulbright Scholars. The 36th president of the United States, Lyndon B. Johnson, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloning
Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. In the field of biotechnology, cloning is the process of creating cloned organisms (copies) of cells and of DNA fragments (molecular cloning). Etymology Coined by Herbert J. Webber, the term clone derives from the Ancient Greek word (), ''twig'', which is the process whereby a new plant is created from a twig. In botany, the term ''lusus'' was used. In horticulture, the spelling ''clon'' was used until the early twentieth century; the final ''e'' came into use to indicate the vowel is a "long o" instead of a "short o". Since the term entered the popular lexicon in a more general context, the spelling ''clone'' has been used exclusively. Natural cloning Cloning is a natural form of reproduction that has allowed life forms to spread for hundreds of millions of years. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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