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Sedges
The Cyperaceae () are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large; botanists have described some 5,500 known species in about 90 generathe largest being the "true sedges" (genus ''Carex''), with over 2,000 species. Distribution Cyperaceae species are widely distributed with the centers of diversity for the group occurring in tropical Asia and tropical South America. While sedges grow in almost all environments, many thrive in wetlands A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ... or in poor soils. Ecological communities dominated by sedges are known as s or as sedge meadows. Classification Some species superficially resemble the closely related Juncaceae , rushes and the more distantly related grasse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedge
The Cyperaceae () are a family of graminoid (grass-like), monocotyledonous flowering plants known as wikt:sedge, sedges. The family (biology), family is large; botanists have species description, described some 5,500 known species in about 90 genus, generathe largest being the "true wikt:sedge, sedges" (genus ''Carex''), with over 2,000 species. Distribution Cyperaceae species are widely distributed with the centers of diversity for the group occurring in tropical Asia and tropical South America. While sedges grow in almost all environments, many thrive in wetlands or in poor soils. Community (ecology), Ecological communities dominated by sedges are known as s or as sedge meadows. Classification Some species superficially resemble the closely related Juncaceae , rushes and the more distantly related grasses. Features distinguishing members of the sedge family from grasses or rushes are stems with triangular cross-sections (with occasional exceptions, a notable example be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carex
''Carex'' is a vast genus of over 2,000 species of grass-like plants in the family (biology), family Cyperaceae, commonly known as sedges (or seg, in older books). Other members of the family Cyperaceae are also called sedges, however those of genus ''Carex'' may be called true sedges, and it is the most species-rich genus in the family. The study of ''Carex'' is known as caricology. Description All species of ''Carex'' are perennial plant, perennial, although some species, such as ''Carex bebbii, C. bebbii'' and ''Carex viridula, C. viridula'' can fruit in their first year of growth, and may not survive longer. They typically have rhizomes, stolons or short rootstocks, but some species grow in tufts (caespitose). The culm (botany), culm – the flower-bearing stalk – is unbranched and usually erect. It is usually distinctly triangular in section. The leaf, leaves of ''Carex'' comprise a blade, which extends away from the stalk, and a sheath, which encloses part of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graminoid
In botany and ecology, a graminoid refers to a herbaceous plant with a grass-like morphology, i.e., elongated culms with long, blade-like leaves. They are contrasted with forbs, herbaceous plants without grass-like features. The plants most often referred to include the families Poaceae (grasses in the strict sense), Cyperaceae (sedges), and Juncaceae (rushes). These are not closely related but belong to different clades in the order Poales. The grasses (Poaceae) are by far the largest family, with some 12,000 species. Ecology Besides their similar morphology, graminoids share a widespread occurrence and often dominance in open habitats such as grasslands or marshes. They can, however, also be found in the understory of forests. Sedges and rushes tend to prefer wetter habitats than grasses. Gallery File:Pitrus (Juncus effusus) 05.JPG, alt=Common rush in shallow water, Common rush ('' Juncus effusus''), Juncaceae File:Cyperus capitatus 01.jpg, alt=Nutsedge on dune, Nutse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''Ēṓs'', 'Eos, Dawn') and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grass
Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and species cultivated in lawns and pasture. The latter are commonly referred to collectively as grass. With around 780 genera and around 12,000 species, the Poaceae is the fifth-largest :plant families, plant family, following the Asteraceae, Orchidaceae, Fabaceae and Rubiaceae. The Poaceae are the most economically important plant family, including staple foods from domesticated cereal crops such as maize, wheat, rice, oats, barley, and millet for people and as forage, feed for livestock, meat-producing animals. They provide, through direct human consumption, just over one-half (51%) of all dietary energy; rice provides 20%, wheat supplies 20%, maize (corn) 5.5%, and other grains 6%. Some members of the Poaceae are used as building materials ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wetlands
A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially in the soils. Wetlands form a transitional zone between waterbodies and dry lands, and are different from other terrestrial or aquatic ecosystems due to their vegetation's roots having adapted to oxygen-poor waterlogged soils. They are considered among the most biologically diverse of all ecosystems, serving as habitats to a wide range of aquatic and semi-aquatic plants and animals, with often improved water quality due to plant removal of excess nutrients such as nitrates and phosphorus. Wetlands exist on every continent, except Antarctica. The water in wetlands is either freshwater, brackish or saltwater. The main types of wetland are defined based on the dominant plants and the source of the water. For example, ''marshes'' are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Community (ecology)
In ecology, a community is a group or association (ecology), association of Population ecology, populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, or life assemblage. The term community has a variety of uses. In its simplest form it refers to groups of organisms in a specific place or time, for example, "the fish community of Lake Ontario before industrialization". Community ecology or synecology is the study of the interactions between species in communities on many spatial and temporal scales, including the distribution, structure, abundance, demography, and biological interaction, interactions of coexisting populations. The primary focus of community ecology is on the interactions between populations as determined by specific genotypic and phenotypic characteristics. It is important to understand the origin, maintenance, and consequences ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedge Meadow
A hydrosere is a plant succession which occurs in an area of fresh water such as in oxbow lakes and kettle lakes. In time, an area of open freshwater will naturally dry out, ultimately becoming woodland. During this change, a range of different landtypes such as swamp and marsh will succeed each other. The succession from open water to climax woodland takes centuries or millennia. Some intermediate stages will last a shorter time than others. For example, swamp may change to marsh within a decade or less. How long it takes will depend largely on the amount of siltation occurring in the area of open water. Stages Hydrosere is the primary succession sequence which develops in aquatic environments such as lakes and ponds. It results in conversion of water body and its community into a land community. The early changes are allogenic as inorganic particles such as sand and clay are washed from catchment areas and begin filling the basin of the water body. Later, remains of dead pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juncaceae
Juncaceae is a family of flowering plants, commonly known as the rush family. It consists of 8 genera and about 464 known species of slow-growing, rhizomatous, herbaceous monocotyledonous plants that may superficially resemble grasses and sedges. They often grow on infertile soils in a wide range of moisture conditions. The best-known and largest genus is ''Juncus''. Most of the ''Juncus'' species grow exclusively in wetland habitats. A few rushes, such as '' Juncus bufonius'' are annuals, but most are perennials. Despite the apparent similarity, Juncaceae are not counted among the plants with the vernacular name bulrush. Description The leaves are evergreen and well-developed in a basal aggregation on an erect stem. They are alternate and tristichous (i.e., with three rows of leaves up the stem, each row of leaves arising one-third of the way around the stem from the previous leaf). Only in the genus ''Distichia'' are the leaves distichous. The rushes of the genus ''Juncus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllotaxis
In botany, phyllotaxis () or phyllotaxy is the arrangement of leaf, leaves on a plant stem. Phyllotactic spirals form a distinctive class of patterns in nature. Leaf arrangement The basic leaf#Arrangement on the stem, arrangements of leaves on a stem are opposite and alternate (also known as spiral). Leaves may also be Whorl (botany), whorled if several leaves arise, or appear to arise, from the same level (at the same Node (botany), node) on a stem. With an opposite leaf arrangement, two leaves arise from the stem at the same level (at the same Node (botany), node), on opposite sides of the stem. An opposite leaf pair can be thought of as a whorl of two leaves. With an alternate (spiral) pattern, each leaf arises at a different point (node) on the stem. Distichous phyllotaxis, also called "two-ranked leaf arrangement" is a special case of either opposite or alternate leaf arrangement where the leaves on a stem are arranged in two vertical columns on opposite sides of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schoenoplectus Acutus
''Schoenoplectus acutus'' ( syn. ''Scirpus acutus, Schoenoplectus lacustris, Scirpus lacustris'' subsp. ''acutus''), called tule , common tule, hardstem tule, tule rush, hardstem bulrush, or viscid bulrush, is a giant species of sedge in the plant family Cyperaceae, native to freshwater marshes all over North America. The common name derives from the Nāhuatl word ''tōllin'' , and it was first recognized by the early Spanish explorers and missionaries in New Spain who saw the marsh plants in the Central Valley of California as similar to those in the marshes around Mexico City being used to construct shelters by the indigenous inhabitants. Description ''Schoenoplectus acutus'' has a thick, rounded green stem growing to tall, with long, grasslike leaves, and radially symmetrical, clustered, pale brownish flowers. Taxonomy The two varieties are: *''Schoenoplectus acutus'' var. ''acutus'' – northern and eastern North America *''Schoenoplectus acutus'' var. ''occide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilisations. Its 4.7 billion people constitute roughly 60% of the world's population. Asia shares the landmass of Eurasia with Europe, and of Afro-Eurasia with both Europe and Africa. In general terms, it is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a social constructionism, historical and cultural construct, as there is no clear physical and geographical separation between them. A commonly accepted division places Asia to the east of the Suez Canal separating it from Africa; and to the east of the Turkish straits, the Ural Mountains an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
