Plants are multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. Plants were treated as one of two kingdoms including all living things that were not animals, all algae and fungi were treated as plants. However, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes. By one definition, plants form the clade Viridiplantae, a group that includes the flowering plants and other gymnosperms and their allies, liverworts and the green algae, but excludes the red and brown algae. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria, their chloroplasts contain b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ability to produce normal amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although asexual reproduction is common.
There are about 320 thousand species of plants, of which the great majority, some 260–290 thousand, are seed plants. Green plants provide a substantial proportion of the world's molecular oxygen and are the basis of most of Earth's ecosystems on land. Plants that produce grain and vegetables form humankind's basic foods, have been domesticated for millennia. Plants have many cultural and other uses, as ornaments, building materials, writing material and, in great variety, they have been the source of medicines and psychoactive drugs; the scientific study of plants is known as a branch of biology. All living things were traditionally placed into one of two groups and animals; this classification may date from Aristotle, who made the distincton between plants, which do not move, animals, which are mobile to catch their food. Much when Linnaeus created the basis of the modern system of scientific classification, these two groups became the kingdoms Vegetabilia and Animalia. Since it has become clear that the plant kingdom as defined included several unrelated groups, the fungi and several groups of algae were removed to new kingdoms.
However, these organisms are still considered plants in popular contexts. The term "plant" implies the possession of the following traits multicellularity, possession of cell walls containing cellulose and the ability to carry out photosynthesis with primary chloroplasts; when the name Plantae or plant is applied to a specific group of organisms or taxon, it refers to one of four concepts. From least to most inclusive, these four groupings are: Another way of looking at the relationships between the different groups that have been called "plants" is through a cladogram, which shows their evolutionary relationships; these are not yet settled, but one accepted relationship between the three groups described above is shown below. Those which have been called "plants" are in bold; the way in which the groups of green algae are combined and named varies between authors. Algae comprise several different groups of organisms which produce food by photosynthesis and thus have traditionally been included in the plant kingdom.
The seaweeds range from large multicellular algae to single-celled organisms and are classified into three groups, the green algae, red algae and brown algae. There is good evidence that the brown algae evolved independently from the others, from non-photosynthetic ancestors that formed endosymbiotic relationships with red algae rather than from cyanobacteria, they are no longer classified as plants as defined here; the Viridiplantae, the green plants – green algae and land plants – form a clade, a group consisting of all the descendants of a common ancestor. With a few exceptions, the green plants have the following features in common, they undergo closed mitosis without centrioles, have mitochondria with flat cristae. The chloroplasts of green plants are surrounded by two membranes, suggesting they originated directly from endosymbiotic cyanobacteria. Two additional groups, the Rhodophyta and Glaucophyta have primary chloroplasts that appear to be derived directly from endosymbiotic cyanobacteria, although they differ from Viridiplantae in the pigments which are used in photosynthesis and so are different in colour.
These groups differ from green plants in that the storage polysaccharide is floridean starch and is stored in the cytoplasm rather than in the plastids. They appear to have had a common origin with Viridiplantae and the three groups form the clade Archaeplastida, whose name implies that their chloroplasts were derived from a single ancient endosymbiotic event; this is the broadest modern definition of the term'plant'. In contrast, most other algae not only have different pigments but have chloroplasts with three or four surrounding membranes, they are not close relatives of the Archaeplastida having acquired chloroplasts separately from ingested or symbiotic green and red algae. They are thus not included in the broadest modern definition of the plant kingdom, although they were in the past; the green plants or Viridiplantae were traditionally divided into the green algae (including
In the APG IV system for the classification of flowering plants, the name asterids denotes a clade. Common examples include the forget-me-nots, the common sunflower, morning glory and sweet potato, lavender, olive, honeysuckle, ash tree, snapdragon, psyllium, garden sage, table herbs such as mint and rosemary, rainforest trees such as Brazil nut. Most of the taxa belonging to this clade had been referred to the Asteridae in the Cronquist system and to the Sympetalae in earlier systems; the name asterids resembles the earlier botanical name but is intended to be the name of a clade rather than a formal ranked name, in the sense of the ICBN. The phylogenetic tree presented hereafter has been proposed by the APG IV project. Genetic analysis carried out after APG II maintains that the sister to all other asterids are the Cornales. A second order that split from the base of the asterids are the Ericales; the remaining orders cluster into two clades, the lamiids and the campanulids. The structure of both of these clades has changed in APG III.
In APG III system, the following clades were renamed: euasterids I → lamiids euasterids II → campanulids Asterids in Stevens, P. F.. Angiosperm Phylogeny Website. Version 7, May 2006
The Gnaphalieae are a tribe of flowering plants in the family Asteraceae. It is most related to the tribes Anthemideae and Calenduleae; this group is most diverse in Southern Africa and Australia. It is sometimes called the pussy's-toes tribe. There are only a few genera with species native to temperate regions: Anaphalis, Gamochaeta, Leontopodium and Pseudognaphalium; the classification of the tribe into subtribes is unclear, with a number of past classifications not being supported by late 20th-century evidence. Sources: FNA Data related to Gnaphalieae at Wikispecies Media related to Gnaphalieae at Wikimedia Commons UniProt. "Tribe Gnaphalieae". Retrieved 2008-05-16
Asteraceae or Compositae is a large and widespread family of flowering plants. The family has 32,913 accepted species names, in 1,911 genera and 13 subfamilies. In terms of numbers of species, the Asteraceae are rivaled only by the Orchidaceae.. Nearly all members bear their flowers in dense heads surrounded by involucral bracts; when viewed from a distance, each capitulum may have the appearance of being a single flower. Enlarged outer flowers in the capitula may resemble petals, the involucral bracts may look like a calyx; the name Asteraceae comes from the type genus Aster, from the Ancient Greek ἀστήρ, meaning star, refers to the star-like form of the inflorescence. Compositae is an older name that refers to the "composite" nature of the capitula, which consist of many individual flowers. Most members of Asteraceae are annual or perennial herbs, but a significant number are shrubs, vines, or trees; the family has a worldwide distribution, from the polar regions to the tropics, colonizing a wide variety of habitats.
It is most common in the semiarid regions of subtropical and lower temperate latitudes. The Asteraceae may represent as much as 10% of autochthonous flora in many regions of the world. Asteraceae is an economically important family, providing products such as cooking oils, sunflower seeds, sweetening agents, coffee substitutes and herbal teas. Several genera are of horticultural importance, including pot marigold, Calendula officinalis, various daisies, chrysanthemums, dahlias and heleniums. Asteraceae are important in herbal medicine, including Grindelia and many others. A number of species are considered invasive, most notably in North America, introduced by European settlers who used the young leaves as a salad green; the study of this family is known as synantherology. The name Asteraceae comes to international scientific vocabulary from New Latin, from Aster, the type genus, + -aceae, a standardized suffix for plant family names in modern taxonomy; the genus name comes from the Classical Latin word aster, "star", which came from Ancient Greek ἀστήρ, "star".
Compositae means "composite" and refers to the characteristic inflorescence, a special type of pseudanthium found in only a few other angiosperm families. The vernacular name daisy applied to members of this family, is derived from the Old English name of the daisy: dæġes ēaġe, meaning "day's eye"; this is because the petals close at dusk. Asteraceae species have a cosmopolitan distribution, are found everywhere except Antarctica and the extreme Arctic, they are numerous in tropical and subtropical regions. Compositae, the original name for Asteraceae, were first described in 1792 by the German botanist Paul Dietrich Giseke. Traditionally, two subfamilies were recognised: Cichorioideae; the latter has been shown to be extensively paraphyletic, has now been divided into 12 subfamilies, but the former still stands. The phylogenetic tree presented below is based on Panero & Funk updated in 2014, now includes the monotypic Famatinanthoideae; the diamond denotes a poorly supported node, the dot a poorly supported node.
It is noteworthy that the four subfamilies Asteroideae, Cichorioideae and Mutisioideae contain 99% of the species diversity of the whole family. Because of the morphological complexity exhibited by this family, agreeing on generic circumscriptions has been difficult for taxonomists; as a result, several of these genera have required multiple revisions. Members of the Asteraceae are herbaceous plants, but some shrubs and trees do exist, they are easy to distinguish from other plants because of their characteristic inflorescence and other shared characteristics. However, determining genera and species of some groups such as Hieracium is notoriously difficult. Members of the Asteraceae produce taproots, but sometimes they possess fibrous root systems. Stems are herbaceous aerial branched cylindrical with glandular hairs erect but can be prostrate to ascending; some species have underground stems in the form of rhizomes. These can be woody depending on the species; the leaves and the stems often contain secretory canals with resin or latex.
The leaves can be opposite, or whorled. They may be simple, but are deeply lobed or otherwise incised conduplicate or revolute; the margins can be entire or toothed. In plants of the family Asteraceae, what appears to be a single flower is a cluster of much smaller flowers; the overall appearance of the cluster, as a single flower, functions in attracting pollinators in the same way as the structure of an individual flower in some other plant families. The older family name, comes from the fact that what appears to be a single flower is a composite of smaller flowers; the "petals" or "sunrays" in a sunflower head are individual strap-sha
South Africa the Republic of South Africa, is the southernmost country in Africa. It is bounded to the south by 2,798 kilometres of coastline of Southern Africa stretching along the South Atlantic and Indian Oceans. South Africa is the largest country in Southern Africa and the 25th-largest country in the world by land area and, with over 57 million people, is the world's 24th-most populous nation, it is the southernmost country on the mainland of the Eastern Hemisphere. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different African languages, nine of which have official status; the remaining population consists of Africa's largest communities of European and multiracial ancestry. South Africa is a multiethnic society encompassing a wide variety of cultures and religions, its pluralistic makeup is reflected in the constitution's recognition of 11 official languages, the fourth highest number in the world. Two of these languages are of European origin: Afrikaans developed from Dutch and serves as the first language of most coloured and white South Africans.
The country is one of the few in Africa never to have had a coup d'état, regular elections have been held for a century. However, the vast majority of black South Africans were not enfranchised until 1994. During the 20th century, the black majority sought to recover its rights from the dominant white minority, with this struggle playing a large role in the country's recent history and politics; the National Party imposed apartheid in 1948. After a long and sometimes violent struggle by the African National Congress and other anti-apartheid activists both inside and outside the country, the repeal of discriminatory laws began in 1990. Since 1994, all ethnic and linguistic groups have held political representation in the country's liberal democracy, which comprises a parliamentary republic and nine provinces. South Africa is referred to as the "rainbow nation" to describe the country's multicultural diversity in the wake of apartheid; the World Bank classifies South Africa as an upper-middle-income economy, a newly industrialised country.
Its economy is the second-largest in Africa, the 34th-largest in the world. In terms of purchasing power parity, South Africa has the seventh-highest per capita income in Africa; however and inequality remain widespread, with about a quarter of the population unemployed and living on less than US$1.25 a day. South Africa has been identified as a middle power in international affairs, maintains significant regional influence; the name "South Africa" is derived from the country's geographic location at the southern tip of Africa. Upon formation, the country was named the Union of South Africa in English, reflecting its origin from the unification of four separate British colonies. Since 1961, the long form name in English has been the "Republic of South Africa". In Dutch, the country was named Republiek van Zuid-Afrika, replaced in 1983 by the Afrikaans Republiek van Suid-Afrika. Since 1994, the Republic has had an official name in each of its 11 official languages. Mzansi, derived from the Xhosa noun umzantsi meaning "south", is a colloquial name for South Africa, while some Pan-Africanist political parties prefer the term "Azania".
South Africa contains human-fossil sites in the world. Archaeologists have recovered extensive fossil remains from a series of caves in Gauteng Province; the area, a UNESCO World Heritage site, has been branded "the Cradle of Humankind". The sites include one of the richest sites for hominin fossils in the world. Other sites include Gondolin Cave Kromdraai, Coopers Cave and Malapa. Raymond Dart identified the first hominin fossil discovered in Africa, the Taung Child in 1924. Further hominin remains have come from the sites of Makapansgat in Limpopo Province and Florisbad in the Free State Province, Border Cave in KwaZulu-Natal Province, Klasies River Mouth in Eastern Cape Province and Pinnacle Point and Die Kelders Cave in Western Cape Province; these finds suggest that various hominid species existed in South Africa from about three million years ago, starting with Australopithecus africanus. There followed species including Australopithecus sediba, Homo ergaster, Homo erectus, Homo rhodesiensis, Homo helmei, Homo naledi and modern humans.
Modern humans have inhabited Southern Africa for at least 170,000 years. Various researchers have located pebble tools within the Vaal River valley. Settlements of Bantu-speaking peoples, who were iron-using agriculturists and herdsmen, were present south of the Limpopo River by the 4th or 5th century CE, they displaced and absorbed the original Khoisan speakers, the Khoikhoi and San peoples. The Bantu moved south; the earliest ironworks in modern-day KwaZulu-Natal Province are believed to date from around 1050. The southernmost group was the Xhosa people, whose language incorporates certain linguistic traits from the earlier Khoisan people; the Xhosa reached the Great Fish River, in today's Eastern Cape Province. As they migrated, these larger Iron Age populations
The eudicots, Eudicotidae or eudicotyledons are a clade of flowering plants, called tricolpates or non-magnoliid dicots by previous authors. The botanical terms were introduced in 1991 by evolutionary botanist James A. Doyle and paleobotanist Carol L. Hotton to emphasize the evolutionary divergence of tricolpate dicots from earlier, less specialized, dicots; the close relationships among flowering plants with tricolpate pollen grains was seen in morphological studies of shared derived characters. These plants have a distinct trait in their pollen grains of exhibiting three colpi or grooves paralleling the polar axis. Molecular evidence confirmed the genetic basis for the evolutionary relationships among flowering plants with tricolpate pollen grains and dicotyledonous traits; 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 adopted in botany to refer to one of the two largest clades of angiosperms, monocots being the other.
The remaining angiosperms include magnoliids and what are sometimes referred to as basal angiosperms or paleodicots, but these terms have not been or adopted, as they do not refer to a monophyletic group. 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; these pollens have three or more pores set in furrows called colpi. In contrast, most of the other seed plants produce monosulcate pollen, with a single pore set in a differently oriented groove called the sulcus; the name "tricolpates" is preferred by some botanists to avoid confusion with the dicots, a nonmonophyletic group. Numerous familiar plants are eudicots, including many common food plants and ornamentals; some common and familiar eudicots include members of the sunflower family such as the common dandelion, the forget-me-not and other members of its family, buttercup and macadamia. Most leafy trees of midlatitudes belong to eudicots, with notable exceptions being magnolias and tulip trees which belong to magnoliids, Ginkgo biloba, not an angiosperm.
The name "eudicots" is used in the APG system, of 1998, APG II system, of 2003, for classification of angiosperms. It is applied to a monophyletic group, which includes most of the dicots. "Tricolpate" is a synonym for the "Eudicot" monophyletic group, the "true dicotyledons". The number of pollen grain furrows or pores helps classify the flowering plants, with eudicots having three colpi, other groups having one sulcus. Pollen apertures are any modification of the wall of the pollen grain; these modifications include thinning and pores, they serve as an exit for the pollen contents and allow shrinking and swelling of the grain caused by changes in moisture content. The elongated apertures/ furrows in the pollen grain are called colpi, along with pores, are a chief criterion for identifying the pollen classes; 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. The Pentapetalae can be divided into three clades: Dilleniales superrosids consisting of Saxifragales and rosids superasterids consisting of Santalales, Berberidopsidales and asteridsThis division of the eudicots is shown in the following cladogram: The following is a more detailed breakdown according to APG IV, showing within each clade and orders: clade Eudicots order Ranunculales order Proteales order Trochodendrales order Buxales clade Core eudicots order Gunnerales order Dilleniales clade Superrosids order Saxifragales clade Rosids order Vitales clade Fabids order Fabales order Rosales order Fagales order Cucurbitales order Oxalidales order Malpighiales order Celastrales order Zygophyllales clade Malvids order Geraniales order Myrtales order Crossosomatales order Picramniales order Malvales order Brassicales order Huerteales order Sapindales clade Superasterids order Berberidopsidales order Santalales order Caryophyllales clade Asterids order Cornales order Ericales clade Campanulids order Aquifoliales order Asterales order Escalloniales order Bruniales order Apiales order Dipsacales order Paracryphiales clade Lamiids order Solanales order Lamiales order Vahliales order Gentianales order Boraginales order Garryales order Metteniusales order Icacinales Eudicots at the Encyclopedia of Life Eudicots, Tree of Life Web Project Dicots Plant Life Forms
Binomial nomenclature called binominal nomenclature or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomen, binominal name or a scientific name; the first part of the name – the generic name – identifies the genus to which the species belongs, while the second part – the specific name or specific epithet – identifies the species within the genus. For example, humans belong within this genus to the species Homo sapiens. Tyrannosaurus rex is the most known binomial; the formal introduction of this system of naming species is credited to Carl Linnaeus beginning with his work Species Plantarum in 1753. 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; the application of binomial nomenclature is now governed by various internationally agreed codes of rules, of which the two most important are the International Code of Zoological Nomenclature for animals and the International Code of Nomenclature for algae and plants.
Although the general principles underlying binomial nomenclature are common to these two codes, there are some differences, both in the terminology they use and in their precise rules. In modern usage, the first letter of the first part of the name, the genus, is always capitalized in writing, while that of the second part is not when derived from a proper noun such as the name of a person or place. 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 binomial name is given, at least when it is first mentioned, the date of publication may be specified. In zoology "Patella vulgata Linnaeus, 1758"; the name "Linnaeus" tells the reader who it was that first published a description and name for this species of limpet. "Passer domesticus". The original name given by Linnaeus was Fringilla domestica; 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, although nomenclatorial catalogs include such information.
In botany "Amaranthus retroflexus L." – "L." is the standard abbreviation used in botany for "Linnaeus". "Hyacinthoides italica Rothm. – Linnaeus first named this bluebell species Scilla italica. The name is composed of two word-forming elements: "bi", a Latin prefix for two, "-nomial", relating to a term or terms; the word "binomium" was used in Medieval Latin to mean a two-term expression in mathematics. Prior to the adoption of the modern binomial system of naming species, a scientific name consisted of a generic name combined with a specific name, from one to several words long. Together they formed a system of polynomial nomenclature; these names had two separate functions. First, to designate or label the species, second, to be a diagnosis or description. In a simple genus, containing only two species, it was easy to tell them apart with a one-word genus and a one-word specific name; such "polynomial names" may sometimes look like binomials, but are different. For example, Gerard's herbal describes various kinds of spiderwort: "The first is called Phalangium ramosum, Branched Spiderwort.
The other... 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, more known by his Latinized name Carl Linnaeus, 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 specific name; the Bauhins' genus names were retained in many of these, but the descriptive part was reduced to a single word. Linnaeus's trivial names introduced an important new idea, namely that the function of a name could be to give a species a unique label; this meant. Thus Gerard's Phalangium ephemerum virginianum became Tradescantia virgi