1.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
2.
Plant
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Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. The term is generally limited to the green plants, which form an unranked clade Viridiplantae. This includes the plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants have cell walls containing cellulose and obtain most of their energy from sunlight via photosynthesis by primary chloroplasts and their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic and have lost the ability to produce amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although reproduction is also common. There are about 300–315 thousand species of plants, of which the great majority, green plants provide most of the worlds molecular oxygen and are the basis of most of Earths ecologies, especially on land. Plants that produce grains, fruits and vegetables form humankinds basic foodstuffs, Plants play many roles in culture. They are used as ornaments and, until recently and in variety, they have served as the source of most medicines. The scientific study of plants is known as botany, a branch of biology, Plants are one of the two groups into which all living things were traditionally divided, the other is animals. The division goes back at least as far as Aristotle, who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus created the basis of the system of scientific classification. Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, however, these organisms are still often considered plants, particularly in popular contexts. When the name Plantae or plant is applied to a group of organisms or taxon. The evolutionary history of plants is not yet settled. Those which have been called plants are in bold, the way in which the groups of green algae are combined and named varies considerably between authors. Algae comprise several different groups of organisms which produce energy through photosynthesis, most conspicuous among the algae are the seaweeds, multicellular algae that may roughly resemble land plants, but are classified among the brown, red and green algae. Each of these groups also includes various microscopic and single-celled organisms
3.
Flowering plant
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The flowering plants, also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 416 families, approx. 13,164 known genera and a total of c.295,383 known species, etymologically, angiosperm means a plant that produces seeds within an enclosure, in other words, a fruiting plant. The term angiosperm comes from the Greek composite word meaning enclosed seeds, the ancestors of flowering plants diverged from gymnosperms in the Triassic Period, during the range 245 to 202 million years ago, and the first flowering plants are known from 160 mya. They diversified extensively during the Lower Cretaceous, became widespread by 120 mya, angiosperms differ from other seed plants in several ways, described in the table. These distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants, the amount and complexity of tissue-formation in flowering plants exceeds that of gymnosperms. The vascular bundles of the stem are arranged such that the xylem and phloem form concentric rings, in the dicotyledons, the bundles in the very young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium, the soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Among the monocotyledons, the bundles are more numerous in the stem and are scattered through the ground tissue. They contain no cambium and once formed the stem increases in diameter only in exceptional cases, the characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, and provide the most trustworthy external characteristics for establishing relationships among angiosperm species, the function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The floral apparatus may arise terminally on a shoot or from the axil of a leaf, occasionally, as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. There are two kinds of cells produced by flowers. Microspores, which divide to become pollen grains, are the male cells and are borne in the stamens. The female cells called megaspores, which divide to become the egg cell, are contained in the ovule. The flower may consist only of parts, as in willow. Usually, other structures are present and serve to protect the sporophylls, the individual members of these surrounding structures are known as sepals and petals. The outer series is usually green and leaf-like, and functions to protect the rest of the flower, the inner series is, in general, white or brightly colored, and is more delicate in structure. It functions to attract insect or bird pollinators, attraction is effected by color, scent, and nectar, which may be secreted in some part of the flower
4.
Monocotyledon
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Monocotyledons, commonly referred to as monocots, are flowering plants whose seeds typically contain only one embryonic leaf, or cotyledon. However, molecular research has shown that while the monocots form a monophyletic group or clade. Monocots have almost always recognized as a group, but with various taxonomic ranks. The APG III system of 2009 recognises a clade called monocots, the monocots include about 60,000 species. The largest family in this group by number of species are the orchids, about half as many species belong to the true grasses, which are economically the most important family of monocots. In agriculture the majority of the biomass produced comes from monocots and these include not only major grains, but also forage grasses, sugar cane, and the bamboos. Other economically important monocot crops include various palms, bananas, gingers and their relatives, turmeric and cardamom, asparagus and the onions and garlic family. Additionally most of the bulbs, plants cultivated for their blooms, such as lilies, daffodils, irises, amaryllis, cannas, bluebells. The monocots or monocotyledons have, as the name implies, a single cotyledon, or embryonic leaf, from a diagnostic point of view the number of cotyledons is neither a particularly useful characteristic, nor is it completely reliable. Nevertheless, monocots are sufficiently distinctive that there has rarely been disagreement as to membership of this group, however, morphological features that reliably characterise major clades are rare. Thus monocots are distinguishable from other angiosperms both in terms of their uniformity and diversity, although largely herbaceous, some arboraceous monocots reach great height, length and mass. The latter include agaves, palms, pandans, and bamboos and this creates challenges in water transport that monocots deal with in various ways. Some such as species of Yucca develop anomalous secondary growth, while palm trees, the axis undergoes primary thickening, that progresses from internode to internode, resulting in a typical inverted conical shape of the basal primary axis. The limited conductivity also contributes to limited branching of the stems, despite these limitations a wide variety of adaptive growth forms has resulted from epiphytic orchids and bromeliads to submarine Alismatales and mycotrophic Burmanniaceae and Triuridaceae. Other monocots, particularly Poales have adopted a life form. Leaves The cotyledon, the primordial Angiosperm leaf consists of a proximal leaf base or hypophyll, in moncots the hypophyll tends to be the dominant part in contrast to other angiosperms. Mature monocot leaves are narrow and linear, forming a sheathing around the stem at its base. There is usually only one leaf per node because the leaf base encompasses more than half the circumference, the evolution of this monocot characteristic has been attributed to developmental differences in early zonal differentiation rather than meristem activity
5.
Poales
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The Poales are a large order of flowering plants in the monocotyledons, and includes families of plants such as the grasses, bromeliads, and sedges. Sixteen plant families are recognized by botanists to be part of Poales. The flowers are small, enclosed by bracts, and arranged in inflorescences. The flowers of species are wind pollinated, the seeds usually contain starch. It did not include the Bromeliaceae and Mayaceae, but had the additional families Prioniaceae, Sparganiaceae, the morphology-based Cronquist system did not include an order named Poales, assigning these families to the orders Bromeliales, Cyperales, Hydatellales, Juncales, Restionales and Typhales. The earliest known fossils include pollen and fruits, major lineages within the Poales have been referred to as bromeliad, cyperid, xyrid, graminid, and restiid clades. A phylogenetic analysis resolved most relationships within the order but found support for the monophyly of the cyperid clade. The relationship between Centrolepidaceae and Restoniaceae within the clade remains unclear, the first may actually be embedded in the latter. Within the order, by far the most important family economically is the family of grasses, which includes barley, maize, millet, rice, many Bromeliaceae are used as ornamental plants. Bremer, K. Gondwanan Evolution of the Grass Alliance of Families, judd, W. S. C. S. Campbell, E. A. Kellogg, P. F. Stevens, M. J. Donoghue. Plant Systematics, A Phylogenetic Approach, 2nd edition, linder, H. Peter, Rudall, Paula J. Evolutionary History of the Poales. Annual Review of Ecology, Evolution, and Systematics, flora of the Southeastern United States,48
6.
Poaceae
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Poaceae or Gramineae is a large and nearly ubiquitous family of monocotyledonous flowering plants known as grasses. Poaceae includes the cereal grasses, bamboos and the grasses of natural grassland and cultivated lawns, Grasses have stems that are hollow except at the nodes and narrow alternate leaves borne in two ranks. The lower part of each leaf encloses the stem, forming a leaf-sheath, with ca 780 genera and around 12,000 species, Poaceae are the fifth-largest plant family, following the Asteraceae, Orchidaceae, Fabaceae and Rubiaceae. Grasslands such as savannah and prairie grasses are dominant are estimated to constitute 40. 5% of the land area of the Earth, excluding Greenland. Grasses are also an important part of the vegetation in many habitats, including wetlands, forests. Though commonly called grasses, seagrasses, rushes, and sedges fall outside this family, the rushes and sedges are related to the Poaceae, being members of the order Poales, but the seagrasses are members of order Alismatales. The name Poaceae was given by John Hendley Barnhart in 1895, based on the tribe Poeae described in 1814 by Robert Brown, the term is derived from the Ancient Greek πόα. Grasses include some of the most versatile plant life-forms, a cladogram shows subfamilies and approximate species numbers in brackets, Before 2005, fossil findings indicated that grasses evolved around 55 million years ago. Recent findings of grass-like phytoliths in Cretaceous dinosaur coprolites have pushed this back to 66 million years ago. In 2011, revised dating of the origins of the rice tribe Oryzeae suggested a date as early as 107 to 129 Mya, a multituberculate mammal with grass-eating adaptations seems to suggest that grasses were already around at 120 mya. This separation occurred within the short time span of about 4 million years. Grass leaves are always alternate and distichous, and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem, the leaf blades of many grasses are hardened with silica phytoliths, which discourage grazing animals, some, such as sword grass, are sharp enough to cut human skin. A membranous appendage or fringe of hairs called the ligule lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath, flowers of Poaceae are characteristically arranged in spikelets, each having 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. A spikelet consists of two 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 flowers are usually hermaphroditic—maize being an important exception—and anemophilous or wind-pollinated, 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. This complex structure can be seen in the image on the right, the fruit of grasses is a caryopsis, in which the seed coat is fused to the fruit wall
7.
Carl Linnaeus
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Carl Linnaeus, also known after his ennoblement as Carl von Linné, was a Swedish botanist, physician, and zoologist, who formalised the modern system of naming organisms called binomial nomenclature. He is known by the father of modern taxonomy. Many of his writings were in Latin, and his name is rendered in Latin as Carolus Linnæus, Linnaeus was born in the countryside of Småland, in southern Sweden. He received most of his education at Uppsala University. He lived abroad between 1735 and 1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands and he then returned to Sweden, where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on journeys through Sweden to find and classify plants. In the 1750s and 1760s, he continued to collect and classify animals, plants, and minerals, at the time of his death, he was one of the most acclaimed scientists in Europe. The philosopher Jean-Jacques Rousseau sent him the message, Tell him I know no man on earth. The German writer Johann Wolfgang von Goethe wrote, With the exception of Shakespeare and Spinoza, Swedish author August Strindberg wrote, Linnaeus was in reality a poet who happened to become a naturalist. Among other compliments, Linnaeus has been called Princeps botanicorum, The Pliny of the North and he is also considered as one of the founders of modern ecology. In botany, the abbreviation used to indicate Linnaeus as the authority for species names is L. In older publications, sometimes the abbreviation Linn. is found, Linnæus was born in the village of Råshult in Småland, Sweden, on 23 May 1707. He was the first child of Nicolaus Ingemarsson and Christina Brodersonia and his siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, and Emerentia Linnæa. One of a line of peasants and priests, Nils was an amateur botanist, a Lutheran minister. Christina was the daughter of the rector of Stenbrohult, Samuel Brodersonius, a year after Linnæus birth, his grandfather Samuel Brodersonius died, and his father Nils became the rector of Stenbrohult. The family moved into the rectory from the curates house, even in his early years, Linnæus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and often showed flowers to Linnaeus, soon Linnæus was given his own patch of earth where he could grow plants
8.
Great Plains
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The region is known for supporting extensive cattle ranching and dry farming. The Canadian portion of the Plains is known as the Prairies, some geographers include some territory of northern Mexico in the Plains, but many stop at the Rio Grande. The term Great Plains is used in the United States to describe a sub-section of the even more vast Interior Plains physiographic division and it also has currency as a region of human geography, referring to the Plains Indians or the Plains States. There is no region referred to as the Great Plains in The Atlas of Canada, in terms of human geography, the term prairie is more commonly used in Canada, and the region is known as the Prairie Provinces or simply the Prairies. The region is about 500 mi east to west and 2,000 mi north to south, much of the region was home to American bison herds until they were hunted to near extinction during the mid/late 19th century. It has an area of approximately 500,000 sq mi, current thinking regarding the geographic boundaries of the Great Plains is shown by this map at the Center for Great Plains Studies, University of Nebraska–Lincoln. The term Great Plains, for the region west of about the 96th or 98th meridian, nevin Fennemans 1916 study, Physiographic Subdivision of the United States, brought the term Great Plains into more widespread usage. Before that the region was almost invariably called the High Plains, today the term High Plains is used for a subregion of the Great Plains. The Great Plains are the westernmost portion of the vast North American Interior Plains, during the Cretaceous Period, the Great Plains were covered by a shallow inland sea called the Western Interior Seaway. However, during the Late Cretaceous to the Paleocene, the seaway had begun to recede, leaving thick marine deposits. During the Cenozoic era, specifically about 25 million years ago during the Miocene and Pliocene epochs, existing forest biomes declined and grasslands became much more widespread. The grasslands provided a new niche for mammals, including many ungulates and glires, traditionally, the spread of grasslands and the development of grazers have been strongly linked. The vast majority of animals became extinct in North America at the end of the Pleistocene. In general, the Great Plains have a variety of weather through the year, with very cold and harsh winters and very hot. Wind speeds are very high, especially in winter. Grasslands are among the least protected biomes, humans have converted much of the prairies for agricultural purposes or to create pastures. The Great Plains have dust storms mostly every year or so, the 100th meridian roughly corresponds with the line that divides the Great Plains into an area that receive 20 in or more of rainfall per year and an area that receives less than 20 in. The region is subjected to extended periods of drought, high winds in the region may then generate devastating dust storms
9.
Riparian zone
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A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth, Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by hydrophilic plants. In some regions the terms riparian woodland, riparian forest, riparian buffer zone, the word riparian is derived from Latin ripa, meaning river bank. Riparian zones may be natural or engineered for soil stabilization or restoration and these zones are important natural biofilters, protecting aquatic environments from excessive sedimentation, polluted surface runoff and erosion. They supply shelter and food for aquatic animals and shade that limits stream temperature change. When riparian zones are damaged by construction, agriculture or silviculture, biological restoration can take place, usually by human intervention in erosion control and revegetation. If the area adjacent to a watercourse has standing water or saturated soil for as long as a season, because of their prominent role in supporting a diversity of species, riparian zones are often the subject of national protection in a Biodiversity Action Plan. These are also known as a Plant or Vegetation Waste Buffer, research shows that riparian zones are instrumental in water quality improvement for both surface runoff and water flowing into streams through subsurface or groundwater flow. Particularly, the attenuation of nitrate or denitrification of the nitrates from fertilizer in this zone is important. The use of wetland riparian zones shows a high rate of removal of nitrate entering a stream. The meandering curves of a river, combined with vegetation and root systems, slow the flow of water, sediment is trapped, reducing suspended solids to create less turbid water, replenish soils, and build stream banks. Pollutants are filtered from surface runoff, enhancing water quality via biofiltration, the riparian zones also provide wildlife habitat, increased biodiversity, and wildlife corridors, enabling aquatic and riparian organisms to move along river systems avoiding isolated communities. Riparian vegetation can also forage for wildlife and livestock. They provide native landscape irrigation by extending seasonal or perennial flows of water, nutrients from terrestrial vegetation are transferred to aquatic food webs. The vegetation surrounding the stream helps to shade the water, mitigating water temperature changes, the vegetation also contributes wood debris to streams, which is important to maintaining geomorphology. From a social aspect, riparian zones contribute to nearby property values through amenity and views, space is created for riparian sports such as fishing, swimming and launching for vessels and paddlecraft. The protection of zones is often a consideration in logging operations. The undisturbed soil, soil cover, and vegetation provide shade, plant litter, and woody material, factors such as soil types and root structures, climatic conditions and vegetative cover determine the effectiveness of riparian buffering
10.
Rhizome
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In botany and dendrology, a rhizome is a modified subterranean stem of a plant that is usually found underground, often sending out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks and rootstocks, Rhizomes develop from axillary buds and are diageotropic or grow perpendicular to the force of gravity. The rhizome also retains the ability to new shoots to grow upwards. If a rhizome is separated into pieces, each piece may be able to rise to a new plant. The plant uses the rhizome to store starches, proteins, and these nutrients become useful for the plant when new shoots must be formed or when the plant dies back for the winter. This is a known as vegetative reproduction and is used by farmers and gardeners to propagate certain plants. This also allows for lateral spread of grasses like bamboo and bunch grasses, examples of plants that are propagated this way include hops, asparagus, ginger, irises, Lily of the Valley, cannas, and sympodial orchids. Some rhizomes which are used directly in cooking include ginger, turmeric, galangal, stored rhizomes are subject to bacterial and fungal infections, making them unsuitable for replanting and greatly diminishing stocks. However, rhizomes can also be produced artificially from tissue cultures, the ability to easily grow rhizomes from tissue cultures leads to better stocks for replanting and greater yields. The plant hormones ethylene and jasmonic acid have found to help induce and regulate the growth of rhizomes. Ethylene that was applied externally was found to affect internal ethylene levels, knowledge of how to use these hormones to induce rhizome growth could help farmers and biologists producing plants grown from rhizomes more easily cultivate and grow better plants. The poplars are an example of trees that propagate using a rhizome, the Pando colony in Utah is a famous example, which has been living for about 80,000 years. In general, rhizomes have short internodes, they send out roots from the bottom of the nodes, a stem tuber is a thickened part of a rhizome or stolon that has been enlarged for use as a storage organ. In general, a tuber is high in starch, for example, the common potato, the term tuber is often used imprecisely, and is sometimes applied to plants with rhizomes. Some plants have rhizomes that grow above ground or that lie at the surface, including some Iris species. Rhizomes generally form a layer, but in Giant Horsetails. Many rhizomes have culinary value, and some, such as zheergen, are consumed raw. Aspen Corm Mycorrhiza Media related to Rhizomes at Wikimedia Commons
11.
Mycorrhiza
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A mycorrhiza is a symbiotic association between a fungus and the roots of a vascular host plant. The term mycorrhiza refers to the role of the fungi in the plants rhizosphere, mycorrhizae play important roles in soil biology and soil chemistry. In a mycorrhizal association, the fungus colonizes the host plants root tissues, either intracellularly as in arbuscular mycorrhizal fungi, the association is generally mutualistic, but in particular species or in particular circumstances, mycorrhizae may be variously pathogenic in the host plants. Mycorrhizal fungi form a relationship with the roots of most plant species. In such a relationship, both the plants themselves and those parts of the roots that host the fungi, are said to be mycorrhizal, the Orchidaceae are notorious as a family in which the absence of the correct mycorrhizae is fatal even to germinating seeds. Recent research into plants in boreal forests has indicated that mycorrhizal fungi. This relationship was noted when mycorrhizal fungi were found to be hoarding nitrogen from plant roots in times of nitrogen scarcity. Researchers argue that some mycorrhizae distribute nutrients based upon the environment with surrounding plants, the mycorrhizal mutualistic association provides the fungus with relatively constant and direct access to carbohydrates, such as glucose and sucrose. The carbohydrates are translocated from their source to root tissue and on to the fungal partners. The effect is thus to improve the plants mineral absorption capabilities, unaided plant roots may be unable to take up macronutrients that are chemically or physically immobilised, examples include phosphate ions and micronutrients such as iron. One form of such immobilization occurs in soil with clay content. The mycelium of the fungus can, however, access many such nutrient sources. Thus many plants are able to obtain phosphate, without using soil as a source, Suillus tomentosus, a basidiomycete fungus, produces specialized structures known as tuberculate ectomycorrhizae with its plant host lodgepole pine. These structures have shown to host nitrogen fixing bacteria which contribute a significant amount of nitrogen. The mechanisms by which mycorrhizae increase absorption include some that are physical, chemically, the cell membrane chemistry of fungi differs from that of plants. For example, they may secrete organic acid that dissolve or chelate many ions, mycorrhizae are especially beneficial for the plant partner in nutrient-poor soils. Mycorrhizal plants are more resistant to diseases, such as those caused by microbial soil-borne pathogens. AMF was also correlated with soil biological fertility variables such as soil fungi and soil bacteria
12.
Inflorescence
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An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the part of the shoot of seed plants where flowers are formed. Inflorescence can also be defined as the portion of a plant that bears a cluster of flowers in a specific pattern. The stem holding the whole inflorescence is called a peduncle and the major axis holding the flowers or more branches within the inflorescence is called the rachis, the stalk of each single flower is called a pedicel. A flower that is not part of an inflorescence is called a solitary flower, any flower in an inflorescence may be referred to as a floret, especially when the individual flowers are particularly small and borne in a tight cluster, such as in a pseudanthium. The fruiting stage of an inflorescence is known as an infructescence, inflorescences may be simple or complex. The rachis may be one of several types, including Single, Composite, Umbel and these terms are general representations as plants in nature can have a combination of types. Inflorescences usually have modified shoots foliage different from the part of the plant. Considering the broadest meaning of the term, any leaf associated with an inflorescence is called a bract. A bract is usually located at the node where the stem of the inflorescence forms, joined to the main stem of the plant. They serve a variety of functions which include attracting pollinators and protecting young flowers, according to the presence or absence of bracts and their characteristics we can distinguish, Ebracteate inflorescences, No bracts in the inflorescence. Bracteate inflorescences, The bracts in the inflorescence are very specialised, sometimes reduced to small scales and this use is not technically correct, as, despite their normal appearance, these leaves are considered, in fact, bracts, so that leafy inflorescence is preferable. Leafy-bracted inflorescences, Intermediate between bracteate and leafy inflorescence, if many bracts are present and they are strictly connected to the stem, like in the family Asteraceae, the bracts might collectively be called an involucre. If the inflorescence has a unit of bracts further up the stem. Plant organs can grow according to two different schemes, namely monopodial or racemose and sympodial or cymose, the terminal bud keeps growing and forming lateral flowers. A terminal flower is never formed, the terminal bud forms a terminal flower and then dies out. Other flowers then grow from lateral buds, indeterminate and determinate inflorescences are sometimes referred to as open and closed inflorescences respectively. In an indeterminate inflorescence there is no true terminal flower and the stem usually has a rudimentary end, in many cases the last true flower formed by the terminal bud straightens up, appearing to be a terminal flower
