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.
Eudicots
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The eudicots, Eudicotidae or eudicotyledons are a monophyletic clade of flowering plants that had been called tricolpates or non-magnoliid dicots by previous authors. The close relationships among flowering plants with tricolpate pollen grains was initially seen in studies of shared derived characters. These plants have a trait in their pollen grains of exhibiting three colpi or grooves paralleling the polar axis. Later molecular evidence confirmed the basis for the evolutionary relationships among flowering plants with tricolpate pollen grains. The term means true dicotyledons, as it contains the majority of plants that have been considered dicots and have characteristics of the dicots, the term eudicots has subsequently been widely adopted in botany to refer to one of the two largest clades of angiosperms, monocots being the other. The remaining angiosperms are sometimes referred to as basal angiosperms or paleodicots, the other name for the eudicots is tricolpates, a name which refers to the grooved structure of the pollen. Members of the group have tricolpate pollen, or forms derived from it and these pollens have three or more pores set in furrows called colpi. In contrast, most of the seed plants produce monosulcate pollen. The name tricolpates is preferred by some botanists to avoid confusion with the dicots, numerous familiar plants are eudicots, including many common food plants, trees, and ornamentals. Most leafy trees of midlatitudes also belong to eudicots, with exceptions being magnolias and tulip trees which belong to magnoliids, and Ginkgo biloba. The name eudicots is used in the APG system, of 1998 and it is applied to a clade, a monophyletic group, which includes most of the dicots. The eudicots can be divided into two groups, the basal eudicots and the core eudicots, basal eudicot is an informal name for a paraphyletic group. The core eudicots are a monophyletic group, a 2010 study suggested the core eudicots can be divided into two clades, Gunnerales and a clade called Pentapetalae, comprising all the remaining core eudicots
5.
Rosids
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The rosids are members of a large clade of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms. The clade is divided into 16 to 20 orders, depending upon circumscription and classification and these orders, in turn, together comprise about 140 families. Fossil rosids are known from the Cretaceous period, molecular clock estimates indicate that the rosids originated in the Aptian or Albian stages of the Cretaceous, between 125 and 99.6 million years ago. The name is based upon the name Rosidae, which had usually been understood to be a subclass, in 1967, Armen Takhtajan showed that the correct basis for the name Rosidae is a description of a group of plants published in 1830 by Friedrich Gottlieb Bartling. The clade was later renamed Rosidae and has been variously delimited by different authors, the name rosids is informal and not assumed to have any particular taxonomic rank like the names authorized by the ICBN. The rosids are monophyletic based upon evidence found by molecular phylogenetic analysis, three different definitions of the rosids were used. Some authors included the orders Saxifragales and Vitales in the rosids, others excluded both of these orders. The circumscription used in this article is that of the APG IV classification, which includes Vitales, the rosids and Saxifragales form the superrosids clade. This is one of three groups compose the Pentapetalae, the others being Dilleniales and the superasterids. The rosids consist of two groups, the order Vitales and the eurosids, the eurosids, in turn, are divided into two groups, fabids and malvids. The rosids consist of 17 orders, in addition to Vitales, there are 8 orders in fabids and 8 orders in malvids. Some of the orders have only recently been recognized and these are Vitales, Zygophyllales, Crossosomatales, Picramniales, and Huerteales. The phylogeny of Rosids shown below is adapted from the Angiosperm Phylogeny Group website, the nitrogen-fixing clade contains a high number of actinorhizal plants. Not all plants in this clade are actinorhizal, however, media related to Rosids at Wikimedia Commons
6.
Myrtales
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The Myrtales are an order of flowering plants placed as a sister to the eurosids II clade as of the publishing of the Eucalyptus grandis genome in June 2014. The APG III system of classification for angiosperms still places it within the eurosids, the following families are included as of APG III, Alzateaceae S. A. Graham Combretaceae R. Br. The Cronquist system gives essentially the composition, except the Vochysiaceae are removed to the order Polygalales. The families Sonneratiaceae, Trapaceae, and Punicaceae are removed from the Lythraceae, in the classification system of Dahlgren the Myrtales were in the superorder Myrtiflorae. The APG III system agrees with the older Cronquist circumscriptions of treating Psiloxylaceae and Heteropyxidaceae within Myrtaceae, ellagitannins are reported in dicotyledoneous angiospermes, and notably in species in the order Myrtales. Myrtales is dated to have begun 89-99 million years ago in Australasia, there is some contention as to that date however, which was obtained using nuclear DNA. When looking at chloroplast DNA, the ancestor is instead considered to have evolved in the mid-cretaceous period in Southeast Africa. Although the APG system classifies myrtales as within the eurosids, the published genome of Eucalyptus grandis places the order myrtales as a sister to the eurosids rather than inside them. The discrepancy is thought to have due to the difference between using a large number of taxa versus using a large number of genes for constructing a phylogeny. Conti, E. Erikkson, T. Schonenberger, J. Sytsma, K. J. Baum, early Tertiary Out-of-India Dispersal of Crypteroniaceae, Evidence from Phylogeny and Molecular Dating. Schönenberger, J. Conti, E. Molecular phylogeny and floral evolution of Penaeaceae, Oliniaceae, Rhynchocalycaceae, and Alzateaceae
7.
Myrtaceae
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Myrtaceae is the myrtle family, a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pohutukawa, the bay rum tree, clove, guava, acca, allspice, all species are woody, with essential oils, and flower parts in multiples of four or five. One notable character of the family is that the phloem is located on both sides of the xylem, not just outside as in most other plants, the leaves are evergreen, alternate to mostly opposite, simple, and usually with an entire margin. The flowers have a number of five petals, though in several genera the petals are minute or absent. The stamens are usually conspicuous, brightly coloured and numerous. Recent estimates suggest the Myrtaceae include approximately 5950 species in ca 132 genera, the family has a wide distribution in tropical and warm-temperate regions of the world, and are typically common in many of the worlds biodiversity hotspots. Genera with capsular fruits such as Eucalyptus, Corymbia, Angophora, Leptospermum, genera with fleshy fruits have their greatest concentrations in eastern Australia and Malesia and the Neotropics. Eucalyptus is a dominant, nearly ubiquitous genus in the more parts of Australia. Eucalyptus regnans is the tallest flowering plant in the world, other important Australian genera are Callistemon, Syzygium, and Melaleuca. Species of the genus Osbornia, native to Australasia, are mangroves, eugenia, Myrcia, and Calyptranthes are among the larger genera in the neotropics. Historically, the Myrtaceae were divided into two subfamilies, subfamily Myrtoideae was recognized as having fleshy fruits and opposite, entire leaves. Most genera in this subfamily have one of three recognized types of embryos. The genera of Myrtoideae can be difficult to distinguish in the absence of mature fruits. Myrtoideae are found worldwide in subtropical and tropical regions, with centers of diversity in the Neotropics, northeastern Australia, in contrast, subfamily Leptospermoideae was recognized as having dry, dehiscent fruits and leaves arranged spirally or alternate. The Leptospermoideae are found mostly in Australasia, with a centre of diversity in Australia, many genera in Western Australia have greatly reduced leaves and flowers typical of more xeric habitats. Thus, many workers are now using a recent analysis by Wilson et al. as a point to test further analyses of the family. The genera Heteropyxis and Psiloxylon have been separated as separate families by many authors in the past as Heteropyxidaceae and Psiloxylaceae, however, Wilson et al. included them in Myrtaceae. These two genera are believed to be the earliest arising and surviving lineages of Myrtaceae
8.
Eucalyptus
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Eucalyptus /ˌjuːkəˈlɪptəs/ LHeritier 1789 is a diverse genus of flowering trees and shrubs in the myrtle family, Myrtaceae. Members of the genus dominate the flora of Australia. There are more than 700 species of eucalyptus and most are native to Australia, one species, Eucalyptus deglupta, ranges as far north as the Philippines. Of the 15 species found outside Australia, just nine are exclusively non-Australian, species of eucalyptus are cultivated widely in the tropical and temperate world, including the Americas, Europe, Africa, the Mediterranean Basin, the Middle East, China, and the Indian subcontinent. However, the range over which many eucalypts can be planted in the zone is constrained by their limited cold tolerance. Australia is covered by 92,000,000 hectares of eucalypt forest, Eucalyptus is one of three similar genera that are commonly referred to as eucalypts, the others being Corymbia and Angophora. Many species, though by no means all, are known as gum trees because they exude copious kino from any break in the bark. The generic name is derived from the Greek words ευ well and καλύπτω to cover, Eucalyptus oil finds many uses like in aromatherapy, as a cure for joint pains. Eucalyptus trees show allelopathic effects, they release compounds which inhibit other plant species from growing nearby, on warm days, eucalyptus forests are sometimes shrouded in a smog-like mist of vaporised volatile organic compounds, the Australian Blue Mountains take their name from the haze. A mature eucalyptus may take the form of a low shrub or a large tree. The species can be divided into three main habits and four size categories, as a generalisation forest trees are single-stemmed and have a crown forming a minor proportion of the whole tree height. Woodland trees are single-stemmed, although they may branch at a distance above ground level. Many mallee trees may be so low-growing as to be considered a shrub, two other tree forms are notable in Western Australia and described using the native names mallet and marlock. The mallet is a small to medium-sized tree that does not produce lignotubers and has a long trunk. This is the habit of mature healthy specimens of Eucalyptus occidentalis, E. astringens, E. spathulata, E. gardneri, E. dielsii, E. forrestiana, E. salubris, E. clivicola. The smooth bark of mallets often has a satiny sheen and may be white, cream, grey, green, or copper. The term marlock has been used, in Forest Trees of Australia, it is defined as a small tree without lignotubers. They usually grow in more or less pure stands, clearly recognisable examples are stands of E. platypus, E. vesiculosa, and the unrelated E. stoatei
9.
Binomial nomenclature
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Such a name is called a binomial name, a binomen, binominal name or a scientific name, more informally it is also called a Latin name. The first part of the name identifies the genus to which the species belongs, for example, humans belong to the genus Homo and within this genus to the species Homo sapiens. The formal introduction of system of naming species is credited to Carl Linnaeus. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus. Although the general principles underlying binomial nomenclature are common to these two codes, there are differences, both in the terminology they use and in their precise rules. Similarly, both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a name is usually given, at least when it is first mentioned. In zoology Patella vulgata Linnaeus,1758, the original name given by Linnaeus was Fringilla domestica, the parentheses indicate that the species is now considered to belong in a different genus. The ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, in botany Amaranthus retroflexus L. – L. is the standard abbreviation used in botany for Linnaeus. – Linnaeus first named this bluebell species Scilla italica, Rothmaler transferred it to the genus Hyacinthoides, the ICN does not require that the dates of either publication be specified. Prior to the adoption of the binomial system of naming species. Together they formed a system of polynomial nomenclature and these names had two separate functions. First, to designate or label the species, and second, to be a diagnosis or description, such polynomial names may sometimes look like binomials, but are significantly different. For example, Gerards herbal describes various kinds of spiderwort, The first is called Phalangium ramosum, Branched Spiderwort, is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia. The Latin phrases are short descriptions, rather than identifying labels, the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words. The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné. It was in his 1753 Species Plantarum that he first began using a one-word trivial name together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as an epithet or specific name
