1.
Botany
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Botany, also called plant science, plant biology or phytology, is the science of plant life and a branch of biology. A botanist or plant scientist is a scientist who specialises in this field, the term botany comes from the Ancient Greek word βοτάνη meaning pasture, grass, or fodder, βοτάνη is in turn derived from βόσκειν, to feed or to graze. Nowadays, botanists study approximately 410,000 species of plants of which some 391,000 species are vascular plants. Medieval physic gardens, often attached to monasteries, contained plants of medical importance and they were forerunners of the first botanical gardens attached to universities, founded from the 1540s onwards. One of the earliest was the Padua botanical garden and these gardens facilitated the academic study of plants. Efforts to catalogue and describe their collections were the beginnings of plant taxonomy, in the last two decades of the 20th century, botanists exploited the techniques of molecular genetic analysis, including genomics and proteomics and DNA sequences to classify plants more accurately. Modern botany is a broad, multidisciplinary subject with inputs from most other areas of science, dominant themes in 21st century plant science are molecular genetics and epigenetics, which are the mechanisms and control of gene expression during differentiation of plant cells and tissues. Botany originated as herbalism, the study and use of plants for their medicinal properties, many records of the Holocene period date early botanical knowledge as far back as 10,000 years ago. This early unrecorded knowledge of plants was discovered in ancient sites of human occupation within Tennessee, the early recorded history of botany includes many ancient writings and plant classifications. Examples of early works have been found in ancient texts from India dating back to before 1100 BC, in archaic Avestan writings. His major works, Enquiry into Plants and On the Causes of Plants, constitute the most important contributions to science until the Middle Ages. De Materia Medica was widely read for more than 1,500 years, important contributions from the medieval Muslim world include Ibn Wahshiyyas Nabatean Agriculture, Abū Ḥanīfa Dīnawarīs the Book of Plants, and Ibn Bassals The Classification of Soils. In the early 13th century, Abu al-Abbas al-Nabati, and Ibn al-Baitar wrote on botany in a systematic and scientific manner and these gardens continued the practical value of earlier physic gardens, often associated with monasteries, in which plants were cultivated for medical use. They supported the growth of botany as an academic subject, lectures were given about the plants grown in the gardens and their medical uses demonstrated. Botanical gardens came much later to northern Europe, the first in England was the University of Oxford Botanic Garden in 1621, throughout this period, botany remained firmly subordinate to medicine. German physician Leonhart Fuchs was one of the three German fathers of botany, along with theologian Otto Brunfels and physician Hieronymus Bock, Fuchs and Brunfels broke away from the tradition of copying earlier works to make original observations of their own. Bock created his own system of plant classification, physician Valerius Cordus authored a botanically and pharmacologically important herbal Historia Plantarum in 1544 and a pharmacopoeia of lasting importance, the Dispensatorium in 1546. Naturalist Conrad von Gesner and herbalist John Gerard published herbals covering the medicinal uses of plants, naturalist Ulisse Aldrovandi was considered the father of natural history, which included the study of plants
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.
Wood
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Wood is a porous and fibrous structural tissue found in the stems and roots of trees, and other woody plants. It is a material, a natural composite of cellulose fibers which are strong in tension embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, in a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots, Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber. In 2005, the stock of forests worldwide was about 434 billion cubic meters. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy, in 1991 approximately 3.5 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction, a 2011 discovery in the Canadian province of New Brunswick discovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in species by dendrochronology to make inferences about when a wooden object was created. People have used wood for millennia for many purposes, primarily as a fuel or as a material for making houses, tools, weapons, furniture, packaging, artworks. Constructions using wood date back ten thousand years, buildings like the European Neolithic long house were made primarily of wood. Recent use of wood has changed by the addition of steel. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the climate at that time. This process is known as growth, it is the result of cell division in the vascular cambium, a lateral meristem. These cells then go on to form thickened secondary cell walls, composed mainly of cellulose, hemicellulose, if the distinctiveness between seasons is annual, these growth rings are referred to as annual rings. Where there is little seasonal difference growth rings are likely to be indistinct or absent, if the bark of the tree has been removed in a particular area, the rings will likely be deformed as the plant overgrows the scar. It is usually lighter in color than that near the portion of the ring. The outer portion formed later in the season is known as the latewood or summerwood. However, there are differences, depending on the kind of wood
4.
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
5.
Graminoid
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In botany and ecology, the term graminoid refers to a herbaceous plant with a grass-like morphology, i. e. elongated culms with long, blade-like leaves. They are contrasted to forbs, herbaceous plants without grass-like features, the plants most often referred to include the families Poaceae, Cyperaceae, and Juncaceae. These are not closely related but belong to different clades in the order Poales, the grasses are by far the largest family with some 12,000 species. Besides their similar morphology, graminoids share the widespread occurrence and often dominance in open habitats such as grasslands or marshes and they can however also be found in the understory of forests. Sedges and rushes tend to prefer wetter habitats than grasses
6.
Plant stem
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A stem is one of two main structural axes of a vascular plant, the other being the root. The stem is divided into nodes and internodes, The nodes hold one or more leaves. Adventitious roots may also be produced from the nodes, the internodes distance one node from another. The term shoots is often confused with stems, shoots generally refers to new plant growth including both stems and other structures like leaves or flowers. In most plants stems are located above the surface but some plants have underground stems. Stems have four main functions which are, Support for and the elevation of leaves, flowers, the stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits. Transport of fluids between the roots and the shoots in the xylem and phloem Storage of nutrients Production of new living tissue, the normal lifespan of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue, Stems are often specialized for storage, asexual reproduction, protection or photosynthesis, including the following, Acaulescent – used to describe stems in plants that appear to be stemless. Actually these stems are just extremely short, the leaves appearing to rise out of the ground. Arborescent – tree like with woody stems normally with a single trunk, branched – aerial stems are described as being branched or unbranched Bud – an embryonic shoot with immature stem tip. Bulb – a short underground stem with fleshy storage leaves attached, e. g. onion, daffodil. Bulbs often function in reproduction by splitting to form new bulbs or producing small new bulbs termed bulblets, bulbs are a combination of stem and leaves so may better be considered as leaves because the leaves make up the greater part. Caespitose – when stems grow in a mass or clump or in low growing mats. Cladode – a flattened stem that appears more-or-less leaf like and is specialized for photosynthesis, climbing – stems that cling or wrap around other plants or structures. Corm – a short enlarged underground, storage stem, e. g. taro, decumbent – stems that lie flat on the ground and turn upwards at the ends. Fruticose – stems that grow shrublike with woody like habit, herbaceous – non woody, they die at the end of the growing season. Pedicel – stems that serve as the stalk of a flower in an inflorescence or infrutescence. Peduncle – a stem that supports an inflorescence Prickle – a sharpened extension of the outer layers
