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Aristida Rufescens
''Aristida rufescens'' is a grass species native to Madagascar and to Mayotte in the Comoros archipelago. It was described by German agrostologist Ernst Gottlieb von Steudel in 1854. The species is a perennial bunch grass with short rhizomes. Its culms are erect and long, with swollen nodes and hairy leaf sheaths. Leaf blades are long and 3 mm wide; they are stiff, leathery, and convolute. The inflorescence is a panicle in which each spikelet contains one fertile flower. Spikelets are lanceolate and 8.5 mm long. Upper and lower glumes have 1–2 mm long awns, and lateral lemmas have a 13–14 mm long awn, which is three-branched. The grass is a C4 plant. ''Aristida rufescens'' is one of the dominant species in the grasslands A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natural ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MNHN
The French National Museum of Natural History, known in French as the ' (abbreviation MNHN), is the national natural history museum of France and a ' of higher education part of Sorbonne Universities. The main museum, with four galleries, is located in Paris, France, within the Jardin des Plantes on the left bank of the River Seine. It was formally founded in 1793 during the French Revolution, but was begun even earlier in 1635 as the royal garden of medicinal plants. The museum now has 14 sites throughout France. History 17th–18th century File:Jardin du roi 1636.png, The Royal Garden of Medicinal Plants in 1636 File:Buffon statue dsc00979.jpg, Statue of Georges-Louis Leclerc, Comte de Buffon in the formal garden File:Buffon, Georges Louis - Leclerc, comte de – Histoire naturelle, générale et particuliére, 1763 – BEIC 8822844.jpg, Buffon's "Natural History" (1763) File:MNHN-logo.jpg, The museum's seal, designed in 1793, illustrates the three realms of Nature, Collectiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spikelet
A spikelet, in botany, describes the typical arrangement of the flowers of grasses, sedges and some other Monocots. Each spikelet has one or more florets. The spikelets are further grouped into panicles or spikes. The part of the spikelet that bears the florets is called the rachilla. In grasses In Poaceae, the grass family, a spikelet consists of two (or sometimes fewer) bracts at the base, called glumes, followed by one or more florets. A floret consists of the flower surrounded by two bracts, one external—the lemma—and one internal—the palea. The perianth is reduced to two scales, called lodicules, that expand and contract to spread the lemma and palea; these are generally interpreted to be modified sepals. The flowers are usually hermaphroditic—maize being an important exception—and mainly anemophilous or wind-pollinated, although insects occasionally play a role. Lemma Lemma is a phytomorphological term referring to a part of the spikelet. It is the lowermost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Madagascar
The flora of Madagascar consists of more than 12,000 species of plants, as well as a poorly known number of fungi and algae. Around 83% of Madagascar's vascular plants are found only on the island. These endemics include five plant families, 85% of the over 900 orchid species, around 200 species of palms, and such emblematic species as the traveller's tree, six species of baobab and the Madagascar periwinkle. The high degree of endemism is due to Madagascar's long isolation following its separation from the African and Indian landmasses in the Mesozoic, 150–160 and 84–91 million years ago, respectively. However, few plant lineages remain from the ancient Gondwanan flora; most extant plant groups immigrated via across-ocean dispersal well after continental break-up. After its continental separation, Madagascar probably experienced a dry period, and tropical rainforest expanded only later in the Oligocene to Miocene when rainfall increased. Today, humid forests, inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristida
''Aristida'' is a very nearly cosmopolitan genus of plants in the grass family. ''Aristida'' is distinguished by having three awns (bristles) on each lemma of each floret. The genus includes about 300 species found worldwide, often in arid warm regions. This genus is among those colloquially called three-awns wiregrasses, speargrasses and needlegrasses. The name ''Aristida'' is derived from the Latin " arista", meaning "awn". They are characteristic of semiarid grassland. The Wiregrass Region of North America is named for '' A. stricta''. Other locales where this genus is an important component of the ecosystem include the Carolina Bays, the sandhills of the Carolinas, and elsewhere, Mulga scrub in Australia, and the xeric grasslands around Lake Turkana in Africa. Local increases in the abundance of wiregrasses is a good indicator of overgrazing, as livestock avoid them. Description ''Aristida'' stems are ascending to erect, with both basal and cauline leaves. The leave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malagasy Language
Malagasy (; ) is an Austronesian language and the national language of Madagascar. Malagasy is the westernmost Malayo-Polynesian language, brought to Madagascar by the settlement of Austronesian peoples from the Sunda islands around the 5th century AD. The Malagasy language is one of the Barito languages and is most closely related to the Ma'anyan language, still spoken on Borneo to this day. Malagasy also includes numerous Malay loanwords, from the time of the early Austronesian settlement and trading between Madagascar and the Sunda Islands. After c. 1000 AD, Malagasy incorporated numerous Bantu and Arabic loanwords, brought over by traders and new settlers. Malagasy is spoken by around 25 million people in Madagascar and the Comoros. Most people in Madagascar speak it as a first language, as do some people of Malagasy descent elsewhere. Malagasy is divided between two main dialect groups; Eastern and Western. The central plateau of the island, where the capital Antananarivo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Highlands (Madagascar)
The Central Highlands, Central High Plateau, or Hauts-Plateaux are a mountainous biogeographical region in central Madagascar. They include the contiguous part of the island's interior above 800 m (2,600 ft) altitude. The Central Highlands are separated from the Northern Highlands of the northern tip of Madagascar by a low-lying valley, the Mandritsara Window, which has apparently acted as a barrier to dispersal for species in the highlands, leading to species pairs such as ''Voalavo gymnocaudus'' and ''Voalavo antsahabensis'' in the Northern and Central Highlands. Species restricted to the Central Highlands include the bats '' Miniopterus manavi'' and '' Miniopterus sororculus''; the rodents '' Brachyuromys betsileoensis'' and ''Voalavo antsahabensis''; the tenrecs '' Hemicentetes nigriceps'' and '' Oryzorictes tetradactylus''; and the lemur '' Cheirogaleus sibreei''. Because of the continuous habitat of the Central Highlands, there is little local endemism Endemis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grasslands
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area. Definitions Included among the variety of definitions for grasslands are: * "...any plant community, including harvested forages, in which grasses and/or legumes make up the dominant vegetation." * "...terrestrial ecosystems dominated by herbaceous and shrub vegetation, and maintained by fire, grazing, drought and/or freezing temperatures." (Pilot Assessment of Global Ecosystems, 2000) * "A r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C4 Carbon Fixation
carbon fixation or the Hatch–Slack pathway is one of three known photosynthetic processes of carbon fixation in plants. It owes the names to the 1960's discovery by Marshall Davidson Hatch and Charles Roger Slack that some plants, when supplied with 14, incorporate the 14C label into four-carbon molecules first. fixation is an addition to the ancestral and more common carbon fixation. The main carboxylating enzyme in photosynthesis is called RuBisCO, which catalyses two distinct reactions using either (carboxylation) or oxygen (oxygenation) as a substrate. The latter process, oxygenation, gives rise to the wasteful process of photorespiration. photosynthesis reduces photorespiration by concentrating around RuBisCO. To ensure that RuBisCO works in an environment where there is a lot of carbon dioxide and very little oxygen, leaves generally differentiate two partially isolated compartments called mesophyll cells and bundle-sheath cells. is initially fixed in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lanceolate
The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular or irregular, may be smooth or bearing hair, bristles or spines. For more terms describing other aspects of leaves besides their overall morphology see the leaf article. The terms listed here all are supported by technical and professional usage, but they cannot be represented as mandatory or undebatable; readers must use their judgement. Authors often use terms arbitrarily, or coin them to taste, possibly in ignorance of established terms, and it is not always clear whether because of ignorance, or personal preference, or because usages change with time or context, or because of variation between specimens, even specimens from the same plant. For example, whether to call leaves on the same tree "acuminate", "lanceolate", or "linear" could ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panicle
A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are often racemes. A panicle may have determinate or indeterminate growth. This type of inflorescence is largely characteristic of grasses such as oat and crabgrass, as well as other plants such as pistachio and mamoncillo. Botanists use the term paniculate in two ways: "having a true panicle inflorescence" as well as "having an inflorescence with the form but not necessarily the structure of a panicle". Corymb A corymb may have a paniculate branching structure, with the lower flowers having longer pedicels than the upper, thus giving a flattish top superficially resembling an umbel. Many species in the subfamily Amygdaloideae, such as hawthorns and rowans, produce their flowers in corymbs. up'' Sorbus glabrescens'' corymb with fruit See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
