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.
Apiaceae
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Apiaceae or Umbelliferae, is a family of mostly aromatic flowering plants named after the type genus Apium and commonly known as the celery, carrot or parsley family. Most Apiaceae are annual, biennial or perennial herbs, though a minority are woody shrubs or small trees such as Bupleurum fruticosum and their leaves are of variable size and alternately arranged, or with the upper leaves becoming nearly opposite. The leaves may be petiolate or sessile, there are no stipules but the petioles are frequently sheathing and the leaves may be perfoliate. The leaf blade is usually dissected, ternate or pinnatifid, but simple and entire in some genera, commonly, their leaves emit a marked smell when crushed, aromatic to foetid, but absent in some species. The defining characteristic of family is the inflorescence, the flowers nearly always aggregated in terminal umbels. The flowers are perfect and actinomorphic but there may be zygomorphic petals at the edges of the umbel. The flowers are nearly perfectly pentamerous, with five petals, sepals, the androecium consists of five stamens, but there is often variation in the functionality of the stamens even within a single inflorescence. Some flowers are functionally staminate while others are functionally pistillate, pollination of one flower by the pollen of a different flower of the same plant is common. The gynoecium consists of two carpels fused into a single, bicarpellate pistil with an inferior ovary, stylopodia support two styles and secrete nectar, attracting pollinators like flies, mosquitoes, gnats, beetles, moths, and bees. The fruit is a schizocarp consisting of two fused carpels that separate at maturity into two mericarps, each containing a single seed. The fruits of species are dispersed by wind but others such as those of Daucus spp. are covered in bristles. The shape and details of the ornamentation of the fruits are important for identification to species. Apiaceae was first described by John Lindley in 1836, the name is derived from the type genus Apium, which was originally used by Pliny the Elder circa 50 AD for a celery-like plant. The alternative name for the family, Umbelliferae, derives from the inflorescence being generally in the form of a compound umbel, the family was one of the first to be recognized as a distinct group in Jacques Daleschamps 1586 Historia generalis plantarum. With Robert Morison’s 1672 Plantarum umbelilliferarum distribution nova it became the first group of plants for which a study was published. The family is placed within the Apiales order in the APG III classification system. It is closely related to Araliaceae and the boundaries between these families remain unclear, traditionally groups within the family have been delimited largely based on fruit morphology, and the results from this have not been congruent with the more recent molecular phylogenetic analyses. The subfamilial and tribal classification for the family is currently in a state of flux, according to the Angiosperm Phylogeny Website as of July 2014434 genera are in the family Apiaceae
5.
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
6.
Holly
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Ilex /ˈaɪlɛks/, or holly, is a genus of 400 to 600 species of flowering plants in the family Aquifoliaceae, and the only living genus in that family. The species are evergreen or deciduous trees, shrubs, and climbers from tropics to temperate zones worldwide, the genus Ilex is widespread throughout the temperate and subtropical regions of the world. It includes species of trees, shrubs, and climbers, with evergreen or deciduous foliage and its range was more extended in the Tertiary period and many species are adapted to laurel forest habitat. It occurs from sea level to more than 2,000 metres with high mountain species and it is a genus of small, evergreen trees with smooth, glabrous, or pubescent branchlets. The plants are generally slow-growing with some growing to 25 m tall. The type species is the European holly Ilex aquifolium described by Linnaeus, plants in this genus have simple, alternate glossy leaves, frequently with a spiny leaf margin. The inconspicuous flower is white, with four petals. They are generally dioecious, with male and female flowers on different plants, the small fruits of Ilex, although often referred to as berries, are technically drupes. They range in color from red to brown to black, the bones contain up to ten seeds each. Some species produce fruits parthenogenetically, such as the cultivar Nellie R. Stevens, the fruits ripen in winter and thus provide winter colour contrast between the bright red of the fruits and the glossy green evergreen leaves. Hence the cut branches, especially of I. aquifolium, are used in Christmas decoration. The fruits are slightly toxic to humans, and can cause vomiting. However, they are an important food source for birds and other animals, unfortunately this can have negative impacts as well. It has been placed on the Washington State Noxious Weed Control Boards monitor list, Ilex in Latin means the holm-oak or evergreen oak. The name holly in common speech refers to Ilex aquifolium, specifically stems with berries used in Christmas decoration, by extension, holly is also applied to the whole genus. The origin of the holly is considered a reduced form of Old English holen, Middle English Holin. The French word for holly, houx, derives from the Old Low Franconian *hulis, both are related to Old High German hulis, huls, as are Low German/Low Franconian terms like Hülse or hulst. These Germanic words appear to be related to words for holly in Celtic languages, such as Welsh celyn, Breton kelen, several romance languages use the Latin word acrifolium, so Italian agrifoglio, Occitan grefuèlh, etc
7.
Perennial plant
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A perennial plant or simply perennial is a plant that lives for more than two years. The term is used to differentiate a plant from shorter-lived annuals and biennials. The term is widely used to distinguish plants with little or no woody growth from trees and shrubs. Tomato vines, for example, live several years in their natural habitat but are grown as annuals in temperate regions because they dont survive the winter. There is also a class of evergreen, or non-herbaceous, perennials, an intermediate class of plants is known as subshrubs, which retain a vestigial woody structure in winter, e. g. Penstemon. The local climate may dictate whether plants are treated as shrubs or perennials, for instance, many varieties of Fuchsia are shrubs in warm regions, but in colder temperate climates may be cut to the ground every year as a result of winter frosts. The symbol for a plant, based on Species Plantarum by Linnaeus, is. Perennial plants can be short-lived or they can be long-lived, as are some plants like trees. They include an assortment of plant groups from ferns and liverworts to the highly diverse flowering plants like orchids. Plants that flower and fruit only once and then die are termed monocarpic or semelparous, however, most perennials are polycarpic, flowering over many seasons in their lifetime. Perennials typically grow structures that allow them to adapt to living one year to the next through a form of vegetative reproduction rather than seeding. These structures include bulbs, tubers, woody crowns, rhizomes plus others and they might have specialized stems or crowns that allow them to survive periods of dormancy over cold or dry seasons during the year. Many perennials have developed specialized features that allow them to extreme climatic. Some have adapted to hot and dry conditions or cold temperatures. Those plants tend to invest a lot of resource into their adaptations and often do not flower, Many perennials produce relatively large seeds, which can have an advantage, with larger seedlings produced after germination that can better compete with other plants. Some annuals produce many seeds per plant in one season, while some perennials are not under the same pressure to produce large numbers of seeds. In warmer and more favorable climates, perennials grow continuously, in seasonal climates, their growth is limited to the growing season. In some species, perennials retain their foliage all year round, other plants are deciduous perennials, for example, in temperate regions a perennial plant may grow and bloom during the warm part of the year, with the foliage dying back in the winter
8.
Leaf
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A leaf is an organ of a vascular plant and is the principal lateral appendage of the stem. The leaves and stem together form the shoot, Leaves are collectively referred to as foliage, as in autumn foliage. Although leaves can be seen in different shapes, sizes and textures, typically a leaf is a thin, dorsiventrally flattened organ, borne above ground. Most leaves have distinctive upper surface and lower surface that differ in colour, hairiness, broad, flat leaves with complex venation are known as megaphylls and the species that bear them, the majority, as broad-leaved or megaphyllous plants. In others, such as the clubmosses, with different evolutionary origins, some leaves, such as bulb scales are not above ground, and in many aquatic species the leaves are submerged in water. Succulent plants often have thick juicy leaves, but some leaves are without major photosynthetic function and may be dead at maturity, as in some cataphylls, furthermore, several kinds of leaf-like structures found in vascular plants are not totally homologous with them. Examples include flattened plant stems called phylloclades and cladodes, and flattened leaf stems called phyllodes which differ from both in their structure and origin. Many structures of plants, such as the phyllids of mosses and liverworts and even of some foliose lichens. Leaves are the most important organs of most vascular plants and these are then further processed by chemical synthesis into more complex organic molecules such as cellulose, the basic structural material in plant cell walls. The plant must therefore bring these three together in the leaf for photosynthesis to take place. Once sugar has been synthesized, it needs to be transported to areas of growth such as the plant shoots and roots. Vascular plants transport sucrose in a tissue called the phloem. The phloem and xylem are parallel to each other but the transport of materials is usually in opposite directions. Within the leaf these vascular systems branch to form veins which supply as much as the leaf as possible and they are arranged on the plant so as to expose their surfaces to light as efficiently as possible without shading each other, but there are many exceptions and complications. For instance plants adapted to windy conditions may have pendent leaves, such as in many willows, the flat, or laminar, shape also maximises thermal contact with the surrounding air, promoting cooling. Functionally, in addition to photosynthesis the leaf is the site of transpiration and guttation. Many gymnosperms have thin needle-like or scale-like leaves that can be advantageous in cold climates with frequent snow and these are interpreted as reduced from megaphyllous leaves of their Devonian ancestors. For xerophytes the major constraint is not light flux or intensity, some window plants such as Fenestraria species and some Haworthia species such as Haworthia tesselata and Haworthia truncata are examples of xerophytes. and Bulbine mesembryanthemoides
9.
Flower
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A flower, sometimes known as a bloom or blossom, is the reproductive structure found in plants that are floral. The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs, Flowers may facilitate outcrossing or allow selfing. Some flowers produce diaspores without fertilization, Flowers contain sporangia and are the site where gametophytes develop. Many flowers have evolved to be attractive to animals, so as to them to be vectors for the transfer of pollen. After fertilization, the ovary of the flower develops into fruit containing seeds, the essential parts of a flower can be considered in two parts, the vegetative part, consisting of petals and associated structures in the perianth, and the reproductive or sexual parts. A stereotypical flower consists of four kinds of structures attached to the tip of a short stalk, each of these kinds of parts is arranged in a whorl on the receptacle. The four main whorls are as follows, Collectively the calyx, corolla, the next whorl toward the apex, composed of units called petals, which are typically thin, soft and colored to attract animals that help the process of pollination. Androecium, the whorl, consisting of units called stamens. Stamens consist of two parts, a called a filament, topped by an anther where pollen is produced by meiosis. Gynoecium, the innermost whorl of a flower, consisting of one or more units called carpels, the carpel or multiple fused carpels form a hollow structure called an ovary, which produces ovules internally. Ovules are megasporangia and they in turn produce megaspores by meiosis which develop into female gametophytes and these give rise to egg cells. The gynoecium of a flower is described using an alternative terminology wherein the structure one sees in the innermost whorl is called a pistil. A pistil may consist of a carpel or a number of carpels fused together. The sticky tip of the pistil, the stigma, is the receptor of pollen, the supportive stalk, the style, becomes the pathway for pollen tubes to grow from pollen grains adhering to the stigma. The relationship to the gynoecium on the receptacle is described as hypogynous, perigynous, although the arrangement described above is considered typical, plant species show a wide variation in floral structure. These modifications have significance in the evolution of flowering plants and are used extensively by botanists to establish relationships among plant species, the four main parts of a flower are generally defined by their positions on the receptacle and not by their function. Many flowers lack some parts or parts may be modified into other functions and/or look like what is typically another part, in some families, like Ranunculaceae, the petals are greatly reduced and in many species the sepals are colorful and petal-like. Other flowers have modified stamens that are petal-like, the flowers of Peonies and Roses are mostly petaloid stamens
10.
Bract
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In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves and they may be smaller, larger, or of a different color, shape, or texture. Typically, they look different from the parts of the flower. The state of having bracts is referred to as bracteate or bracteolate, some bracts are brightly colored and serve the function of attracting pollinators, either together with the perianth or instead of it. Examples of this type of bract include Euphorbia pulcherrima and Bougainvillea, in grasses, each floret is enclosed in a pair of papery bracts, called the lemma and palea, while each spikelet has a further pair of bracts at its base called glumes. These bracts form the chaff removed from cereal grain during threshing and winnowing, bats may detect acoustic signals from dish-shaped bracts such as those of Marcgravia evenia. A prophyll is a structure, such as a bracteole. The term can mean the lower bract on a peduncle. The frequently showy pair of bracts of Euphorbia species in subgenus Lacanthis are the cyathophylls, bracts subtend the cone scales in the seed cones of many conifers, and in some cases, such as Pseudotsuga, they extend beyond the cone scales. A small bract is called a bracteole or bractlet, technically this is any bract that arises on a pedicel instead of subtending it. Bracts that appear in a whorl subtending an inflorescence are called an involucre. An involucre is a common feature beneath the inflorescences of many Apiaceae, Asteraceae, Dipsacaceae and Polygonaceae, each flower in an inflorescence may have its own whorl of bracts, in this case called an involucel. In this case they may be called chaff, paleas, or receptacular bracts and are usually minute scales or bristles, many asteraceous plants have bracts at the base of each inflorescence. The term involucre is also used for a highly conspicuous bract or bract pair at the base of an inflorescence, in the family Betulaceae, notably in the genera Carpinus and Corylus, the involucre is a leafy structure that protects the developing nuts. Beggar-tick has narrow involucral bracts surrounding each inflorescence, each of which also has a bract below it. There is then a pair of bracts on the main stem. It is a calyx-like extra whorl of floral appendages, each individual segment of the epicalyx is called an episepal because they resemble the sepals. They are present in family Malvaceae, the Hibiscus family, fragaria may or may not have an epicalyx
11.
Grassland
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Grasslands are areas where the vegetation is dominated by grasses, however sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica, grasslands are found in most ecoregions of the Earth. For example, there are five terrestrial ecoregion classifications of the grasslands, savannas, and shrublands biome. Grassland vegetation can vary in height from short, as in chalk grassland, to quite tall, as in the case of North American tallgrass prairie, South American grasslands. Woody plants, shrubs or trees, may occur on some grasslands – forming savannas, scrubby grassland or semi-wooded grassland, as flowering plants and trees, grasses grow in great concentrations in climates where annual rainfall ranges between 500 and 900 mm. The root systems of perennial grasses and forbs form complex mats that hold the soil in place, graminoids are among the most versatile life forms. Existing forest biomes declined, and grasslands became much more widespread, following the Pleistocene ice ages, grasslands expanded in range in the hotter, drier climates, and began to become the dominant land feature worldwide. Grasslands often occur in areas with annual precipitation between 600 mm and 1,500 mm and average annual temperatures ranges from −5 and 20 °C. However, some occur in colder and hotter climatic conditions. Grassland can exist in habitats that are disturbed by grazing or fire. Grasslands dominated by unsown wild-plant communities can be called natural or semi-natural habitats. The majority of grasslands in temperate climates are semi-natural and these grasslands contain many species of wild plants – grasses, sedges, rushes and herbs –25 or more species per square metre is not unusual. Chalk downlands in England can support over 40 species per square metre, in many parts of the world, few examples have escaped agricultural improvement. For example, original North American prairie grasslands or lowland wildflower meadows in the UK are now rare and their associated wild flora equally threatened. Some of the worlds largest expanses of grassland are found in African savanna, grasslands may occur naturally or as the result of human activity. Grasslands created and maintained by human activity are called anthropogenic grasslands, hunting peoples around the world often set regular fires to maintain and extend grasslands, and prevent fire-intolerant trees and shrubs from taking hold. The tallgrass prairies in the U. S. Midwest may have been extended eastward into Illinois, Indiana, much grassland in northwest Europe developed after the Neolithic Period, when people gradually cleared the forest to create areas for raising their livestock. Grassland types by Schimper, meadow steppe savannah Grassland types by Ellenberg & Mueller-Dombois, terrestrial herbaceous communities A. Savannas and related grasslands B
