1.
Galanthus nivalis
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Galanthus nivalis, the snowdrop or common snowdrop, is the best-known and most widespread of the 20 species in its genus, Galanthus. Snowdrops are among the first bulbs to bloom in spring and can form impressive carpets of white in areas where they are native or have been naturalised and they should not be confused with the snowflakes, in the genera Leucojum and Acis. The generic name Galanthus, from the Greek gala and anthos, was given to the genus by Carl Linnaeus in 1735 and he described Galanthus nivalis in his Species Plantarum published in 1753. The epithet nivalis means of the snow, referring either to the flower or the plants early flowering. The common name snowdrop first appeared in the 1633 edition of John Gerards Great Herbal, the derivation of the name is uncertain, although it may have come from the German word Schneetropfen, which was a type of earring popular around that time. Other British traditional common names include February fairmaids, dingle-dangle, Candlemas bells, Marys tapers and, in parts of Yorkshire, Galanthus nivalis is widely grown in gardens, particularly in northern Europe, and is widely naturalised in woodlands in the regions where it is grown. It is, however, native to an area of Europe, from Spain in the west. It is considered naturalised in Great Britain, Belgium, Netherlands, Norway, Sweden, Galanthus nivalis grows to around 7–15 cm tall, flowering between January and April in the northern temperate zone. They are perennial, herbaceous plants grow from bulbs. From between them emerges a solitary, pendulous, bell-shaped white flower, held on a slender pedicel, the flower consists of six tepals, also referred to as segments. The outer three are larger and more convex than the inner ones, the inner flower segments are usually marked on their outer surface with a green or greenish-yellow V- or U-shaped mark over the small sinus at the tip of each tepal. The inner surface has a faint green mark covering all or most of it, occasionally plants are found with green markings on the outer surface of the outer tepals. The six long, pointed anthers open by pores or short slits, the ovary is three-celled, ripening into a three-celled capsule. Each whitish seed has a small, fleshy tail containing substances attractive to ants which distribute the seeds, the leaves die back a few weeks after the flowers have faded. G. nivalis is a plant, but sometimes self-pollination takes place. Snowdrops contain a substance called galantamine which can be helpful in the treatment of Alzheimers disease. Snowdrops contain also an active lectin or agglutinin named GNA for Galanthus nivalis agglutinin, potatoes have been genetically modified with the GNA gene. In 1998 Árpád Pusztai said in an interview on a World in Action programme that his group had observed damage to the intestines and immune systems of rats fed the genetically modified potatoes
2.
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
3.
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
4.
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
5.
Monocotyledon
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Monocotyledons, commonly referred to as monocots, are flowering plants whose seeds typically contain only one embryonic leaf, or cotyledon. However, molecular research has shown that while the monocots form a monophyletic group or clade. Monocots have almost always recognized as a group, but with various taxonomic ranks. The APG III system of 2009 recognises a clade called monocots, the monocots include about 60,000 species. The largest family in this group by number of species are the orchids, about half as many species belong to the true grasses, which are economically the most important family of monocots. In agriculture the majority of the biomass produced comes from monocots and these include not only major grains, but also forage grasses, sugar cane, and the bamboos. Other economically important monocot crops include various palms, bananas, gingers and their relatives, turmeric and cardamom, asparagus and the onions and garlic family. Additionally most of the bulbs, plants cultivated for their blooms, such as lilies, daffodils, irises, amaryllis, cannas, bluebells. The monocots or monocotyledons have, as the name implies, a single cotyledon, or embryonic leaf, from a diagnostic point of view the number of cotyledons is neither a particularly useful characteristic, nor is it completely reliable. Nevertheless, monocots are sufficiently distinctive that there has rarely been disagreement as to membership of this group, however, morphological features that reliably characterise major clades are rare. Thus monocots are distinguishable from other angiosperms both in terms of their uniformity and diversity, although largely herbaceous, some arboraceous monocots reach great height, length and mass. The latter include agaves, palms, pandans, and bamboos and this creates challenges in water transport that monocots deal with in various ways. Some such as species of Yucca develop anomalous secondary growth, while palm trees, the axis undergoes primary thickening, that progresses from internode to internode, resulting in a typical inverted conical shape of the basal primary axis. The limited conductivity also contributes to limited branching of the stems, despite these limitations a wide variety of adaptive growth forms has resulted from epiphytic orchids and bromeliads to submarine Alismatales and mycotrophic Burmanniaceae and Triuridaceae. Other monocots, particularly Poales have adopted a life form. Leaves The cotyledon, the primordial Angiosperm leaf consists of a proximal leaf base or hypophyll, in moncots the hypophyll tends to be the dominant part in contrast to other angiosperms. Mature monocot leaves are narrow and linear, forming a sheathing around the stem at its base. There is usually only one leaf per node because the leaf base encompasses more than half the circumference, the evolution of this monocot characteristic has been attributed to developmental differences in early zonal differentiation rather than meristem activity
6.
Asparagales
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Asparagales is an order of plants in modern classification systems such as the Angiosperm Phylogeny Group and the Angiosperm Phylogeny Web. The order takes its name from the type family Asparagaceae and is placed in the monocots amongst the lilioid monocots, the order has only recently been recognized in classification systems. It was first put forward by Huber in 1977 and later taken up in the Dahlgren system of 1985 and then the APG in 1998,2003 and 2009. Before this, many of its families were assigned to the old order Liliales, DNA sequence analysis indicated that many of the taxa previously included in Liliales should actually be redistributed over three orders, Liliales, Asparagales and Dioscoreales. The boundaries of the Asparagales and of its families have undergone a series of changes in recent years, future research may lead to further changes and ultimately greater stability. In the APG circumscription, Asparagales is the largest order of monocots with 14 families,1,122 genera, the order is clearly circumscribed on the basis of molecular phylogenetics, but is difficult to define morphologically, since its members are structurally diverse. Most species of Asparagales are herbaceous perennials, although some are climbers, the order also contains many geophytes. According to telomere sequence, at least two evolutionary switch-points happened within the order, basal sequence is formed by TTTAGGG like in majority of higher plants. Basal motif was changed to vertebrate-like TTAGGG and finally the most divergent motif CTCGGTTATGGG appears in Allium, one of the defining characteristics of the order is the presence of phytomelanin, a black pigment present in the seed coat, creating a dark crust. Phytomelanin is found in most families of the Asparagales, the leaves of almost all species form a tight rosette, either at the base of the plant or at the end of the stem, but occasionally along the stem. The flowers are not particularly distinctive, being lily type, with six tepals, from an economic point of view, the order Asparagales is second in importance within the monocots to the order Poales. Species are used as food and flavourings, as cut flowers, and as garden ornamentals. Thus although most species in the order are herbaceous, some no more than 15 cm high, there are a number of climbers, as well as several genera forming trees, succulent genera occur in several families. Almost all species have a cluster of leaves, either at the base of the plant or at the end of a more-or-less woody stem as with Yucca. In some cases the leaves are produced along the stem, the flowers are in the main not particularly distinctive, being of a general lily type, with six tepals, either free or fused from the base and up to six stamina. They are frequently clustered at the end of the plant stem and they are generally geophytes, but with linear leaves, and a lack of fine reticular venation. The seeds characteristically have the external epidermis either obliterated, or if present, have a layer of black carbonaceous phytomelanin in species with dry fruits. The inner part of the coat is generally collapsed, in contrast to Liliales whose seeds have a well developed outer epidermis, lack phytomelanin
7.
Amaryllidaceae
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The Amaryllidaceae are a family of herbaceous, mainly perennial and bulbous flowering plants in the monocot order Asparagales. The family takes its name from the genus Amaryllis and is known as the amaryllis family. The leaves are linear, and the flowers are usually bisexual and symmetrical. The petals and sepals are undifferentiated as tepals, which may be fused at the base into a floral tube, allyl sulfide compounds produce the characteristic odour of the onion subfamily. The family, which was created in 1805, now contains about 1600 species, divided into about 75 genera,17 tribes. Over time, it has seen much reorganisation and at times was combined with the related Liliaceae. Since 2009, a broad view has prevailed based on phylogenetics. The family is found in tropical to subtropical areas of the world and includes many garden plants. The Amaryllidaceae are mainly terrestrial flowering plants that are herbaceous or succulent geophytes that are perennial, most genera grow from bulbs, but a few such as Agapanthus, Clivia and Scadoxus develop from rhizomes. The leaves are simple rather fleshy and two-ranked with parallel veins, leaf shape may be linear, strap like, oblong, elliptic, lanceolate or filiform. The leaves which are grouped at the base or arranged alternatively on the stem may be sessile or petiolate. The perianth consists of six undifferentiated tepals arranged in two whorls of three, the tepals are similar in shape and size, and may be free from each other or fused at the base to form a floral tube. In some genera, such as Narcissus, this may be surmounted by cup or trumpet shaped projection and this may be reduced to a mere disc in some species. The position of the ovary varies by subfamily, the Agapanthoideae and Allioideae have superior ovaries, the six stamens are arranged in two whorls of three, occasionally more as in Gethyllis. The fruit is dry and capsule-shaped, or fleshy and berry-like, the Allioideae produce allyl sulfide compounds which give them their characteristic smell. The name Amaryllis had been applied to a number of plants over the course of history. Hexandria monogynia has come to be treated as either liliaceous or amaryllidaceaous over time. From 1763, when Adanson conceived of these genera as Liliaceae it was included in family, placing Amaryllis in Section VII, Narcissi. of his scheme. With de Jussieu came the establishment of organising genera into families in 1789
8.
Amaryllidoideae
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Amaryllidoideae is a subfamily of monocot flowering plants in the family Amaryllidaceae, order Asparagales. The subfamily consists of about seventy genera, with eight hundred species. The Amaryllidoideae are herbaceous, perennial flowering plants, usually with bulbs and their fleshy leaves are arranged in two vertical columns, and their flowers are large. Most of them are bulbous geophytes and many have a history of cultivation as ornamental plants. They are distinguished from the other two Amaryllidaceae subfamilies by their unique alkaloidal chemistry, inferior ovary, and hollow style, the name Amaryllis had been applied to a number of plants over the course of history. When Linnaeus formerly described the type genus Amaryllis, from which the family derives its name, in his Species Plantarum in 1753 and he placed Amaryllis in a grouping he referred to as Hexandria monogynia containing 51 genera in all in his sexual classification scheme. These genera have been treated as either liliaceous or amaryllidaceaous over time, the Amaryllidaceae family was named in 1805, by Jean Henri Jaume Saint-Hilaire. Samuel Frederick Grays A natural arrangement of British plants, John Lindley, in his An Introduction to the Natural System of Botany divided the Monocotyledonous Plants into two tribes. He then further divided the Petaloidea, into 32 orders, including the Amaryllideae, by 1846 Lindley had greatly expanded and refined the treatment of the monocots. Since then seven of Linnaeus genera have consistently placed in a common taxonomic unit of amaryllids. Thus much of what we now consider Amaryllidoideae remained in Liliaceae because the ovary was superior, the introduction of molecular methods in the 1990s confirmed the affinity of three major taxa corresponding to Alliaceae, Agapanthaceae and Amaryllidaceae. In 2009 the Angiosperm Phylogeny Group decided to amalgamate the three families, which form a monophyletic group, into a single family, at first called Alliaceae. The three families then became reduced to subfamilies, so that the historical Amaryllidaceae became subfamily Amaryllidoideae, the relationships between the subfamilies within the Amaryllidaceae and the place of Amaryllidoideae is shown in the Cladogram. Complete resolution of relationships within subfamily Amaryllidoideae has proven difficult. Early studies lacked sufficient resolution for further elucidation of this group, historically a wide variety of infrafamilial classification systems have been proposed for the Amaryllidaceae s. s. In the latter twentieth century there were at least six schemes, including Hutchinson, Traub, Dahlgren, Müller-Doblies and Müller-Doblies, Hickey and King and Meerow and Snijman. Hutchinson was a proponent of the larger Amaryllidaceae, transferring taxa from Liliaceae and had three tribes, Agapantheae, Allieae and Gilliesieae. Hickey and King described ten tribes by which the family were divided, Meerow and Snijder considered thirteen tribes, one with two subtribes
9.
Galantheae
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Galantheae is a tribe of plants belonging to the subfamily Amaryllidoideae of the Amaryllis family. It contains eight genera and approximately 31 species, the position of the ovary is inferior. For a history of the circumscription of Galantheae, see Meerow et al,2006, a narrower sense of the tribe is now favoured, with only three genera. The placement of Galantheae within subfamily Amaryllidoideae is shown in the cladogram, Included genera are. Previously included were, Hannonia Lapiedra Vagaria Galantheae represent one of the three European tribes of Amaryllidaceae, galanthus and Leucojum are common ornamental garden plants
10.
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
11.
Type species
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A similar concept is used for suprageneric groups called a type genus. In botanical nomenclature, these terms have no standing under the code of nomenclature. In botany, the type of a name is a specimen which is also the type of a species name. The species name that has that type can also be referred to as the type of the genus name, names of genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have such types. In bacteriology, a species is assigned for each genus. Every named genus or subgenus in zoology, whether or not currently recognized as valid, is associated with a type species. In practice, however, there is a backlog of untypified names defined in older publications when it was not required to specify a type, a type species is both a concept and a practical system that is used in the classification and nomenclature of animals. The type species represents the species and thus definition for a particular genus name. In the Glossary, type species is defined as The nominal species that is the type of a nominal genus or subgenus. The type species permanently attaches a formal name to a genus by providing just one species within that genus to which the name is permanently linked. The species name in turn is fixed, in theory, to a type specimen, for example, the type species for the land snail genus Monacha is Monacha cartusiana. That genus is placed within the family Hygromiidae. The type genus for that family is the genus Hygromia, the concept of the type species in zoology was introduced by Pierre André Latreille. The International Code of Zoological Nomenclature states that the name of the type species should always be cited. It gives an example in Article 67.1, Astacus marinus Fabricius,1775 was later designated as the type species of the genus Homarus, thus giving it the name Homarus marinus. However, the species of Homarus should always be cited using its original name. 3, the type of the genus name Elodes is quoted as the type of the species name Hypericum aegypticum, Glossary of scientific naming Genetypes – genetic sequence data from type specimens. Holotype Paratype Principle of Typification Type Type genus
12.
Synonym (taxonomy)
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For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies. This name is no longer in use, it is now a synonym of the current scientific name which is Picea abies, unlike synonyms in other contexts, in taxonomy a synonym is not interchangeable with the name of which it is a synonym. In taxonomy, synonyms are not equals, but have a different status, for any taxon with a particular circumscription, position, and rank, only one scientific name is considered to be the correct one at any given time. A synonym cannot exist in isolation, it is always an alternative to a different scientific name, given that the correct name of a taxon depends on the taxonomic viewpoint used a name that is one taxonomists synonym may be another taxonomists correct name. Synonyms may arise whenever the same taxon is described and named more than once, independently. They may also arise when existing taxa are changed, as when two taxa are joined to one, a species is moved to a different genus. To the general user of scientific names, in such as agriculture, horticulture, ecology, general science. A synonym is a name that was used as the correct scientific name but which has been displaced by another scientific name. Thus Oxford Dictionaries Online defines the term as a name which has the same application as another. In handbooks and general texts, it is useful to have mentioned as such after the current scientific name. Synonyms used in this way may not always meet the strict definitions of the synonym in the formal rules of nomenclature which govern scientific names. Changes of scientific name have two causes, they may be taxonomic or nomenclatural, a name change may be caused by changes in the circumscription, position or rank of a taxon, representing a change in taxonomic, scientific insight. A name change may be due to purely nomenclatural reasons, that is, based on the rules of nomenclature, the earliest such name is called the senior synonym, while the later name is the junior synonym. One basic principle of zoological nomenclature is that the earliest correctly published name, synonyms are important because if the earliest name cannot be used, then the next available junior synonym must be used for the taxon. Objective synonyms refer to taxa with the type and same rank. For example, John Edward Gray published the name Antilocapra anteflexa in 1855 for a species of pronghorn, however, it is now commonly accepted that his specimen was an unusual individual of the species Antilocapra americana published by George Ord in 1815. Ords name thus takes precedence, with Antilocapra anteflexa being a subjective synonym. Objective synonyms are common at the level of genera, because for various reasons two genera may contain the type species, these are objective synonyms
13.
Ancient Greek
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Ancient Greek includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD. It is often divided into the Archaic period, Classical period. It is antedated in the second millennium BC by Mycenaean Greek, the language of the Hellenistic phase is known as Koine. Koine is regarded as a historical stage of its own, although in its earliest form it closely resembled Attic Greek. Prior to the Koine period, Greek of the classic and earlier periods included several regional dialects, Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers. It has contributed many words to English vocabulary and has been a subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Epic and Classical phases of the language, Ancient Greek was a pluricentric language, divided into many dialects. The main dialect groups are Attic and Ionic, Aeolic, Arcadocypriot, some dialects are found in standardized literary forms used in literature, while others are attested only in inscriptions. There are also several historical forms, homeric Greek is a literary form of Archaic Greek used in the epic poems, the Iliad and Odyssey, and in later poems by other authors. Homeric Greek had significant differences in grammar and pronunciation from Classical Attic, the origins, early form and development of the Hellenic language family are not well understood because of a lack of contemporaneous evidence. Several theories exist about what Hellenic dialect groups may have existed between the divergence of early Greek-like speech from the common Proto-Indo-European language and the Classical period and they have the same general outline, but differ in some of the detail. The invasion would not be Dorian unless the invaders had some relationship to the historical Dorians. The invasion is known to have displaced population to the later Attic-Ionic regions, the Greeks of this period believed there were three major divisions of all Greek people—Dorians, Aeolians, and Ionians, each with their own defining and distinctive dialects. Often non-west is called East Greek, Arcadocypriot apparently descended more closely from the Mycenaean Greek of the Bronze Age. Boeotian had come under a strong Northwest Greek influence, and can in some respects be considered a transitional dialect, thessalian likewise had come under Northwest Greek influence, though to a lesser degree. Most of the dialect sub-groups listed above had further subdivisions, generally equivalent to a city-state and its surrounding territory, Doric notably had several intermediate divisions as well, into Island Doric, Southern Peloponnesus Doric, and Northern Peloponnesus Doric. The Lesbian dialect was Aeolic Greek and this dialect slowly replaced most of the older dialects, although Doric dialect has survived in the Tsakonian language, which is spoken in the region of modern Sparta. Doric has also passed down its aorist terminations into most verbs of Demotic Greek, by about the 6th century AD, the Koine had slowly metamorphosized into Medieval Greek
14.
Genus
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A genus is a taxonomic rank used in the biological classification of living and fossil organisms in biology. In the hierarchy of classification, genus comes above species. In binomial nomenclature, the name forms the first part of the binomial species name for each species within the genus. Felis catus and Felis silvestris are two species within the genus Felis, Felis is a genus within the family Felidae. The composition of a genus is determined by a taxonomist, the standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. Moreover, genera should be composed of units of the same kind as other genera. The term comes from the Latin genus, a noun form cognate with gignere, linnaeus popularized its use in his 1753 Species Plantarum, but the French botanist Joseph Pitton de Tournefort is considered the founder of the modern concept of genera. The scientific name of a genus may be called the name or generic epithet. It plays a role in binomial nomenclature, the system of naming organisms. The rules for the names of organisms are laid down in the Nomenclature Codes. The standard way of scientifically describing species and other lower-ranked taxa is by binomial nomenclature, the generic name forms its first half. For example, the gray wolfs binomial name is Canis lupus, with Canis being the name shared by the wolfs close relatives. The specific name is written in lower-case and may be followed by names in zoology or a variety of infraspecific names in botany. Especially with these names, when the generic name is known from context. Because animals are typically only grouped within subspecies, it is written as a trinomen with a third name. Dog breeds, meanwhile, are not scientifically distinguished, there are several divisions of plant species and therefore their infraspecific names generally include contractions explaining the relation. For example, the genus Hibiscus includes hundreds of other species apart from the Rose of Sharon or common garden hibiscus, Rose of Sharon doesnt have subspecies but has cultivars that carry desired traits, such as the bright white H. syriaca Diana. Hawaiian hibiscus, meanwhile, includes several separate species, since not all botanists agree on the divisions or names between species, it is common to specify the source of the name using author abbreviations
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Species
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In biology, a species is the basic unit of biological classification and a taxonomic rank. A species is defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is problematic, for example, with hybridisation, in a species complex of hundreds of similar microspecies, or in a ring species, the boundaries between closely related species become unclear. Other ways of defining species include similarity of DNA, morphology, all species are given a two-part name, a binomial. The first part of a binomial is the genus to which the species belongs, the second part is called the specific name or the specific epithet. For example, Boa constrictor is one of four species of the Boa genus, Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped that species could evolve given sufficient time, Charles Darwins 1859 book The Origin of Species explained how species could arise by natural selection. Genes can sometimes be exchanged between species by horizontal transfer, and species may become extinct for a variety of reasons. In his biology, Aristotle used the term γένος to mean a kind, such as a bird or fish, a kind was distinguished by its attributes, for instance, a bird has feathers, a beak, wings, a hard-shelled egg, and warm blood. A form was distinguished by being shared by all its members, Aristotle believed all kinds and forms to be distinct and unchanging. His approach remained influential until the Renaissance, when observers in the Early Modern period began to develop systems of organization for living things, they placed each kind of animal or plant into a context. Many of these early delineation schemes would now be considered whimsical, animals likewise that differ specifically preserve their distinct species permanently, one species never springs from the seed of another nor vice versa. In the 18th century, the Swedish scientist Carl Linnaeus classified organisms according to shared physical characteristics and he established the idea of a taxonomic hierarchy of classification based upon observable characteristics and intended to reflect natural relationships. At the time, however, it was widely believed that there was no organic connection between species, no matter how similar they appeared. However, whether or not it was supposed to be fixed, by the 19th century, naturalists understood that species could change form over time, and that the history of the planet provided enough time for major changes. Jean-Baptiste Lamarck, in his 1809 Zoological Philosophy, described the transmutation of species, proposing that a species could change over time, in 1859, Charles Darwin and Alfred Russel Wallace provided a compelling account of evolution and the formation of new species. Darwin argued that it was populations that evolved, not individuals and this required a new definition of species. Darwin concluded that species are what appear to be, ideas
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Bulb
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In botany, a bulb is structurally a short stem with fleshy leaves or leaf bases that function as food storage organs during dormancy. A bulbs leaf bases, also known as scales, generally do not support leaves, at the center of the bulb is a vegetative growing point or an unexpanded flowering shoot. The base is formed by a stem, and plant growth occurs from this basal plate. Roots emerge from the underside of the base, and new stems, tunicate bulbs have dry, membranous outer scales that protect the continuous lamina of fleshy scales. Species in the genera Allium, Hippeastrum, Narcissus, and Tulipa all have tunicate bulbs, non-tunicate bulbs, such as Lilium and Fritillaria species, lack the protective tunic and have looser scales. The technical term geophyte encompasses plants that form underground organs, including bulbs as well as tubers. Some epiphytic orchids form above-ground storage organs called pseudobulbs, that superficially resemble bulbs, nearly all plants that form true bulbs are monocotyledons, and include, Amaryllis, Crinum, Hippeastrum, Narcissus, and several other members of the amaryllis family Amaryllidaceae. This includes onion, garlic, and other alliums, members of the Amaryllid subfamily Allioideae, lily, tulip, and many other members of the lily family Liliaceae. Two groups of Iris species, family Iridaceae, subgenus Xiphium, oxalis, in the family Oxalidaceae, is the only dicotyledon genus that produces true bulbs. Bulbous plant species cycle through vegetative and reproductive stages, the bulb grows to flowering size during the vegetative stage. Certain environmental conditions are needed to trigger the transition from one stage to the next, bulbs dug up before the foliage period is completed will not bloom the following year but then should flower normally in subsequent years. After the foliage period is completed, bulbs may be dug up for replanting elsewhere, any surface moisture should be dried, then the bulbs may be stored up to about 4 months for a fall planting. Storing them much longer than that may cause the bulbs to dry out inside, a bulbil is a small bulb, and may also be called a bulblet, bulbet, or bulbel. Small bulbs can develop or propagate a large bulb, if one or several moderate-sized bulbs form to replace the original bulb, they are called renewal bulbs. Increase bulbs are small bulbs that develop either on each of the leaves inside a bulb, some lilies, such as the tiger lily Lilium lancifolium, form small bulbs, called bulbils, in their leaf axils. Several members of the family, Alliaceae, including Allium sativum, form bulbils in their flower heads, sometimes as the flowers fade. The so-called tree onion forms small onions which are enough for pickling. Some ferns, such as Hen and Chicken Fern produce new plants at the tips of the fronds pinnae, coccoris, Patricia The Curious History of the Bulb Vase
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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
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Herbaceous plant
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Herbaceous plants are plants that have no persistent woody stem above ground. Herbaceous plants may be annuals, biennials or perennials, annual herbaceous plants die completely at the end of the growing season or when they have flowered and fruited, and they then grow again from seed. Herbaceous perennial and biennial plants may have stems that die at the end of the growing season, but parts of the plant survive under or close to the ground from season to season. New growth develops from living tissues remaining on or under the ground, including roots, examples of herbaceous biennials include carrot, parsnip and common ragwort, herbaceous perennials include potato, peony, hosta, mint, most ferns and most grasses. Some relatively fast-growing herbaceous plants are pioneers, or early-successional species, others form the main vegetation of many stable habitats, occurring for example in the ground layer of forests, or in naturally open habitats such as meadow, salt marsh or desert. Some herbaceous plants can grow large, such as the Musa genus. The age of some herbaceous plants can be determined by analyzing annual growth rings in the secondary root xylem
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Family (biology)
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In biological classification, family is one of the eight major taxonomic ranks, it is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks above the rank of genus. In vernacular usage, a family may be named one of its common members, for example, walnuts and hickory trees belong to the family Juglandaceae. What does or does not belong to a family—or whether a family should be recognized at all—are proposed and determined by practicing taxonomists. There are no rules for describing or recognizing a family. Taxonomists often take different positions about descriptions of taxa, and there may be no broad consensus across the community for some time. Some described taxa are accepted broadly and quickly, but others only rarely, if at all, the naming of families is codified by various international codes. In zoological nomenclature, the names of animals end with the suffix -idae. The concept of rank at time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera. Carolus Linnaeus used the word familia in his Philosophia botanica to denote groups of plants, trees, herbs, ferns, palms. He used this term only in the section of the book. In zoology, the family as an intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes. He used families in some but not in all his orders of insects, families can be used for evolutionary, palaeontological and generic studies because they are more stable than lower taxonomic levels such as genera and species
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Leaves
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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
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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
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Petal
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Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators, together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals, the calyx and the corolla together make up the perianth. When the petals and sepals of a flower are difficult to distinguish, examples of plants in which the term tepal is appropriate include genera such as Aloe and Tulipa. Conversely, genera such as Rosa and Phaseolus have well-distinguished sepals and petals, when the undifferentiated tepals resemble petals, they are referred to as petaloid, as in petaloid monocots, orders of monocots with brightly coloured tepals. Since they include Liliales, a name is lilioid monocots. Although petals are usually the most conspicuous parts of animal-pollinated flowers, wind-pollinated species, such as the grasses, the role of the corolla in plant evolution has been studied extensively since Charles Darwin postulated a theory of the origin of elongated corollae and corolla tubes. If the petals are free from one another in the corolla, the corolla in some plants forms a tube. Petals can differ dramatically in different species, the number of petals in a flower may hold clues to a plants classification. For example, flowers on eudicots most frequently have four or five petals while flowers on monocots have three or six petals, although there are exceptions to this rule. The petal whorl or corolla may be radially or bilaterally symmetrical. If all of the petals are essentially identical in size and shape, many flowers are symmetrical in only one plane and are termed irregular or zygomorphic. In irregular flowers, other parts may be modified from the regular form. Examples of zygomorphic flowers may be seen in orchids and members of the pea family, in many plants of the aster family such as the sunflower, Helianthus annuus, the circumference of the flower head is composed of ray florets. Each ray floret is anatomically an individual flower with a large petal. Florets in the centre of the disc typically have no or very reduced petals, in some plants such as Narcissus the lower part of the petals or tepals are fused to form a floral cup above the ovary, and from which the petals proper extend. Petal often consists of two parts, the upper, broad part, similar to leaf blade, called the limb, claws are developed in petals of some flowers of the family Brassicaceae, such as Erysimum cheiri. The inception and further development of shows a great variety of patterns
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Tepal
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A tepal is one of the outer parts of a flower when these parts cannot easily be divided into two kinds, sepals and petals. The term was first proposed by Augustin Pyramus de Candolle in 1827, undifferentiated tepals are believed to be the ancestral condition in flowering plants. For example, Amborella, which is thought to have separated earliest in the evolution of flowering plants, has flowers with undifferentiated tepals, distinct petals and sepals would therefore have arisen by differentiation, probably in response to animal pollination. Tepals formed by similar sepals and petals are common in monocotyledons, in tulips, for example, the first and second whorls both contain structures that look like petals. These are fused at the base to one large, showy. In lilies the organs in the first whorl are separate from the second, where sepals and petals can in principle be distinguished, usage of the term tepal is not always consistent – some authors will refer to sepals and petals where others use tepals in the same context. In some plants the flowers have no petals, and all the tepals are sepals modified to look like petals and these organs are described as petaloid, for example, the sepals of hellebores. When the undifferentiated tepals resemble petals, they are referred to as petaloid, as in petaloid monocots. Since they include Liliales, a name is lilioid monocots. Terms used in the description of tepals include pubescent, puberulent, tepal shape is described in similar terms to those used for leaves. Plant Systematics - Jones, Samuel - McGraw-Hill 1979 ISBN 0-07-032795-5
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Whorl (botany)
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In botany, a whorl is an arrangement of sepals, petals, leaves, stipules or branches that radiate from a single point and surround or wrap around the stem. A whorl consists of at least three elements, a pair of leaves is not called a whorl. A flower lacking any of these structures is said to be incomplete or imperfect. Not all flowers consist of whorls since the parts may instead be spirally arranged, for leaves to grow in whorls is fairly unusual except in plant species with very short internodes. It does however occur in some such as Brabejum stellatifolium and other Proteaceae. In examples such as illustrated, crowded internodes within the whorls alternate with long internodes between the whorls
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Vernation
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Vernation is the formation of new leaves or fronds. In plant anatomy, it is the arrangement of leaves in a bud, in pine trees new leaves are short and encased in sheaths. Each leaf bundle consists of 2 to 5 needles, all the leaves on one section of branch grow in length together. In the cabbage, new leaves are folded over, each covered by the previous leaf, circinate vernation is the manner in which a fern frond emerges. As the fern frond is formed, it is tightly curled so that the growing tip of the frond is protected within a coil. At this stage it is called a crozier or fiddlehead, as the lower parts of the frond expand and toughen up, they begin to photosynthesize, supporting the further growth and expansion of the frond. In the case of many fronds, long hairs or scales provide additional protection to the growing tips before they are fully uncoiled, circinate vernation may also be observed in the extension of leaflets, in the compound leaves of Cycads. Circinate vernation is also typical of the plant family Droseraceae. The process of convolute vernation involves the wrapping of one margin of the blade over the other. This folding mechanism makes the emerging leaf look like a tube, in involute vernation both margins on opposing sides of the leaf are rolled up forming two tubes that meet at the midrib of the leaf. Aestivation — the way in which the petals and sepals of a flower are arranged in a bud, ptyxis — the way an individual leaf is folded within a bud
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Clade
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A clade is a group of organisms that consists of a common ancestor and all its lineal descendants, and represents a single branch on the tree of life. The common ancestor may be an individual, a population, a species, clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently, over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades, the term clade was coined in 1957 by the biologist Julian Huxley to refer to the result of cladogenesis, a concept Huxley borrowed from Bernhard Rensch. Many commonly named groups are clades, for example, rodents or insects, because in each case, their name refers to a common ancestor with all its descendant branches. Rodents, for example, are a branch of mammals that split off after the end of the period when the clade Dinosauria stopped being the dominant terrestrial vertebrates 66 million years ago, the original population and all its descendants are a clade. The rodent clade corresponds to the order Rodentia, and insects to the class Insecta and these clades include smaller clades, such as chipmunk or ant, each of which consists of even smaller clades. The clade rodent is in included in the mammal, vertebrate. The phenomenon of convergent evolution is, however, responsible for cases where there are misleading similarities in the morphology of groups that evolved from different lineages. The publication of Darwins theory of evolution in 1859 gave this view increasing weight, thomas Henry Huxley, an early advocate of evolutionary theory, proposed a revised taxonomy based on clades. For example, he grouped birds with reptiles, based on fossil evidence, german biologist Emil Hans Willi Hennig is considered to be the founder of cladistics. Taxonomists have increasingly worked to make the taxonomic system reflect evolution, when it comes to naming, however, this principle is not always compatible with the traditional rank-based nomenclature. For these and other reasons, phylogenetic nomenclature has been developed, a clade is by definition monophyletic, meaning that it contains one ancestor and all its descendants. The ancestor can be known or unknown, any and all members of a clade can be extant or extinct, the science that tries to reconstruct phylogenetic trees and thus discover clades is called phylogenetics or cladistics, the latter term coined by Ernst Mayr, derived from clade. The results of analyses are tree-shaped diagrams called cladograms, they. Three methods of defining clades are featured in phylogenetic nomenclature, node-, stem-, the relationship between clades can be described in several ways, A clade located within a clade is said to be nested within that clade. In the diagram, the clade, i. e. the apes. Two clades are sisters if they have a common ancestor
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Biogeography
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Biogeography is the study of the distribution of species and ecosystems in geographic space and through time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation, phytogeography is the branch of biogeography that studies the distribution of plants. Zoogeography is the branch that studies distribution of animals, Biogeography is an integrative field of inquiry that unites concepts and information from ecology, evolutionary biology, geology, and physical geography. The short-term interactions within a habitat and species of organisms describe the application of biogeography. Historical biogeography describes the long-term, evolutionary periods of time for broader classifications of organisms, early scientists, beginning with Carl Linnaeus, contributed theories to the contributions of the development of biogeography as a science. Beginning in the century, Europeans explored the world and discovered the biodiversity of life. Linnaeus initiated the ways to classify organisms through his exploration of undiscovered territories, the patterns of species distribution across geographical areas can usually be explained through a combination of historical factors such as, speciation, extinction, continental drift, and glaciation. Through observing the distribution of species, we can see associated variations in sea level, river routes, habitat. Additionally, this science considers the constraints of landmass areas and isolation. As writer David Quammen put it. biogeography does more than ask Which species, and, what is sometimes more crucial, Why not. Modern biogeography often employs the use of Geographic Information Systems, to understand the factors affecting organism distribution, often mathematical models and GIS are employed to solve ecological problems that have a spatial aspect to them. Biogeography is most keenly observed on the worlds islands and these habitats are often much more manageable areas of study because they are more condensed than larger ecosystems on the mainland. They can then apply their understanding to similar but more complex mainland habitats, Islands are very diverse in their biomes, ranging from the tropical to arctic climates. This diversity in habitat allows for a range of species study in different parts of the world. One scientist who recognized the importance of geographic locations was Charles Darwin. Two chapters in On the Origin of Species were devoted to geographical distribution, the first discoveries that contributed to the development of biogeography as a science began in the mid-18th century, as Europeans explored the world and discovered the biodiversity of life. During the 18th century most views on the world were shaped around religion and for many natural theologists, Carl Linnaeus, in the mid-18th century, initiated the ways to classify organisms through his exploration of undiscovered territories. When he noticed that species were not as perpetual as he believed, when Noah’s ark landed on Mount Ararat and the waters receded, the animals dispersed throughout different elevations on the mountain
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March equinox
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In the Northern Hemisphere the March equinox is known as the vernal equinox, and in the Southern Hemisphere as the autumnal equinox. On the Gregorian calendar the Northward equinox can occur as early as 19 March or as late as 21 March. For a common year the computed time slippage is about 5 hours 49 minutes later than the previous year, and for a leap year about 18 hours 11 minutes earlier than the previous year. Balancing the increases of the years against the losses of the leap years keeps the calendar date of the March equinox from drifting more than one day from 20 March each year. The March equinox may be taken to mark the beginning of spring and the end of winter in the Northern Hemisphere but marks the beginning of autumn, in astronomy, the March equinox is the zero point of sidereal time and, consequently, right ascension. It also serves as a reference for calendars and celebrations in many human cultures, the March equinox is one point in time commonly used to determine the length of the tropical year. The mean tropical year is the average of all the tropical years measured from every point along the Earths orbit. The following table shows the small variations in timing over a period of time. The point where the Sun crosses the equator northwards is called the First Point of Aries. However, due to the precession of the equinoxes, this point is no longer in the constellation Aries, by the year 2600 it will be in Aquarius. The Earths axis causes the First Point of Aries to travel westwards across the sky at a rate of one degree every 72 years. It passed by a corner of Cetus at 0°10′ distance in the year 1489. In its apparent motion on the day of an equinox, the Suns disk crosses the Earths horizon directly to the east at dawn—rising, the March equinox, like all equinoxes, is characterized by having an almost exactly equal amount of daylight and night across most latitudes on Earth. Due to refraction of light rays in the Earths atmosphere the Sun will be visible above the horizon even when its disc is completely below the limb of the Earth and these conditions produce differentials of actual durations of light and darkness at various locations on Earth during an equinox. This is most notable at the extreme latitudes, where the Sun may be seen to travel sideways considerably during the dawn. The Persian calendar begins each year at the equinox, observationally determined at Tehran. The Indian national calendar starts the year on the day next to the equinox on 22 March with a 30-day month. The Julian calendar reform lengthened seven months and replaced the intercalary month with a day to be added every four years to February
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Northern Hemisphere
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The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined as being in the celestial hemisphere relative to the invariable plane of the solar system as Earths North pole. Due to the Earths axial tilt, winter in the Northern Hemisphere lasts from the December solstice to the March Equinox, the dates vary each year due to the difference between the calendar year and the astronomical year. Its surface is 60. 7% water, compared with 80. 9% water in the case of the Southern Hemisphere, the Arctic is the region north of the Arctic Circle. Its climate is characterized by cold winters and cool summers, precipitation mostly comes in the form of snow. The Arctic experiences some days in summer when the Sun never sets, the duration of these phases varies from one day for locations right on the Arctic Circle to several months near the North Pole, which is the middle of the Northern Hemisphere. Between the Arctic Circle and the Tropic of Cancer lies the Northern Temperate Zone, the changes in these regions between summer and winter are generally mild, rather than extreme hot or cold. However, a temperate climate can have very unpredictable weather, tropical regions are generally hot all year round and tend to experience a rainy season during the summer months, and a dry season during the winter months. In the Northern Hemisphere, objects moving across or above the surface of the Earth tend to turn to the right because of the coriolis effect, as a result, large-scale horizontal flows of air or water tend to form clockwise-turning gyres. These are best seen in circulation patterns in the North Atlantic. For the same reason, flows of air down toward the surface of the Earth tend to spread across the surface in a clockwise pattern. Thus, clockwise air circulation is characteristic of high pressure weather cells in the Northern Hemisphere, conversely, air rising from the northern surface of the Earth tends to draw air toward it in a counterclockwise pattern. Hurricanes and tropical storms spin counter-clockwise in the Northern Hemisphere, the shadow of a sundial moves clockwise in the Northern Hemisphere. When viewed from the Northern Hemisphere, the Moon appears inverted compared to a view from the Southern Hemisphere, the North Pole faces away from the galactic center of the Milky Way. The Northern Hemisphere is home to approximately 6.57 billion people which is around 90% of the total human population of 7.3 billion people
30.
Spring (season)
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Spring is one of the four conventional temperate seasons, following winter and preceding summer. There are various definitions of spring, but local usage of the term varies according to local climate, cultures. When it is spring in the Northern Hemisphere, it will be autumn in the Southern Hemisphere, at the spring equinox, days are approximately 12 hours long with day length increasing as the season progresses. Spring and springtime refer to the season, and also to ideas of rebirth, rejuvenation, renewal, resurrection, subtropical and tropical areas have climates better described in terms of other seasons, e. g. dry or wet, monsoonal or cyclonic. Often, cultures have locally defined names for seasons which have little equivalence to the terms originating in Europe, Spring is the time when many plants begin to grow and flower. Meteorologists generally define four seasons in many areas, spring, summer, autumn. These are demarcated by the values of their average temperatures on a monthly basis, the three warmest months are by definition summer, the three coldest months are winter and the intervening gaps are spring and autumn. Spring, when defined in this manner, can start on different dates in different regions, in most Northern Hemisphere, temperate locations, spring months are March, April and May, although differences exist from country to country. Most Southern Hemisphere, temperate locations have opposing seasons with spring in September, October and November, in Australia and New Zealand, spring conventionally begins on 1 September and ends 30 November. In some cultures in the Northern Hemisphere, the astronomical Vernal equinox is taken to mark the first day of spring, in Persian culture the first day of spring is the first day of the first month which begins on 20 or 21 March. In other traditions, the equinox is taken as mid-spring, similarly, according to the Celtic tradition, which is based solely on daylight and the strength of the noon sun, spring begins in early February and continues until early May. In Ireland, spring traditionally starts on February 1, St Brigids Day, the beginning of spring is not always determined by fixed calendar dates. These indicators, along with the beginning of spring, vary according to the local climate, most ecologists divide the year into six seasons that have no fixed dates. In addition to spring, ecological reckoning identifies an earlier separate prevernal season between the hibernal and vernal seasons and this is a time when only the hardiest flowers like the crocus are in bloom, sometimes while there is still some snowcover on the ground. During early spring, the axis of the Earth is increasing its tilt relative to the Sun, the hemisphere begins to warm significantly, causing new plant growth to spring forth, giving the season its name. Any snow begins to melt, swelling streams with runoff and any frosts become less severe, in climates that have no snow, and rare frosts, air and ground temperatures increase more rapidly. Many flowering plants bloom at this time of year, in a succession, sometimes beginning when snow is still on the ground. In normally snowless areas, spring may begin as early as February, heralded by the blooming of deciduous magnolias, cherries, and quince, or August in the same way
31.
Autumn
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Autumn, also known as fall in North American English, is one of the four temperate seasons. One of its features is the shedding of leaves from deciduous trees. Some cultures regard the autumnal equinox as mid-autumn, while others with a longer temperature lag treat it as the start of autumn. Meteorologists use a definition based on months, with autumn being September, October and November in the northern hemisphere, in North America, autumn is usually considered to start with the September equinox and end with the winter solstice. As daytime and nighttime temperatures decrease, trees shed their leaves, in traditional East Asian solar term, autumn starts on or around 8 August and ends on or about 7 November. In Ireland, the autumn months according to the meteorological service. In Australia and New Zealand, autumn officially begins on 1 March, the word autumn comes from the ancient Etruscan root autu- and has within it connotations of the passing of the year. It was borrowed by the neighbouring Romans, and became the Latin word autumnus, after the Roman era, the word continued to be used as the Old French word autompne or autumpne in Middle English, and was later normalized to the original Latin. In the Medieval period, there are examples of its use as early as the 12th century. Before the 16th century, harvest was the usually used to refer to the season. The alternative word fall for the season traces its origins to old Germanic languages, the exact derivation is unclear, with the Old English fiæll or feallan and the Old Norse fall all being possible candidates. However, these all have the meaning to fall from a height and are clearly derived either from a common root or from each other. The term came to denote the season in 16th century England, during the 17th century, English emigration to the British colonies in North America was at its peak, and the new settlers took the English language with them. While the term gradually became obsolete in Britain, it became the more common term in North America. The name backend, a common name for the season in Northern England, has today been largely replaced by the name autumn. Association with the transition from warm to cold weather, and its status as the season of the primary harvest, has dominated its themes. In Western cultures, personifications of autumn are usually pretty, well-fed females adorned with fruits, vegetables, many cultures feature autumnal harvest festivals, often the most important on their calendars. There are also the many North American Indian festivals tied to harvest of ripe foods gathered in the wild, the Chinese Mid-Autumn or Moon festival, and many others
32.
Tribe (biology)
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In biology, a tribe is a taxonomic rank above genus, but below family and subfamily. It is sometimes subdivided into subtribes, in zoology, some examples include the tribes Caprini, Hominini, Bombini, and Thunnini. The standard ending for the name of a tribe is -ini. The tribe Hominini is divided into subtribes by some scientists, subtribe Hominina then comprises humans, the standard ending for the name of a zoological subtribe is -ina. In botany, examples include the tribes Acalypheae and Hyacintheae, the standard ending for the name of a botanical tribe is -eae. The tribe Hyacintheae is divided into subtribes, including the subtribe Massoniinae, the standard ending for the name of a botanical subtribe is -inae. In bacteriology, the form of names is as in botany, e. g. Pseudomonadeae
33.
Leucojum
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Leucojum is a small genus of bulbous plants belonging to the Amaryllis family, subfamily Amaryllidoideae native to Eurasia. The spelling Leucoium is also used, other common names include snowbell, dewdrop, and St. Agnes flower. They have narrow, strap-like, dark green leaves, the flowers are small and bell-shaped, white with a green spot at the end of each tepal. Leucojum vernum normally grows 15-20 cm tall, though it may reach up to 35 cm and it flowers one or two weeks later than the snowdrops, i. e. from mid-February to March, as soon as the snow melts in its wild habitat. Leucojum aestivum has a natural range, taking in Europe, southwest Asia and northern Iran. Despite its common name it flowers from April to May, though later than the Spring Snowflake and it is a taller plant than Leucojum vernum, growing to around 60 cm, but its flowers are smaller and are carried in an umbel of between three and seven. Its fleshy seed pods are inflated, allowing them to be dispersed by flood water, pulchellum Briq. native to the western Mediterranean Basin, is smaller,20 cm, and flowers 2 weeks earlier, i. e. from mid-March. Leucojum aestivum Gravetye Giant is a cultivar with larger flowers. It is named after Gravetye Manor, an Elizabethan manor house in West Sussex, England, the house is now a hotel. Leucojum vernum ‘Podpolozje’ is a robust cultivar which combines the properties of var. carpathicum with that of the variant ‘vagneri’, Leucojum aestivum Gravetye Giant and L. vernum have both gained the Royal Horticultural Societys Award of Garden Merit. Nine former members of the genus, characterised by their leaves, solid stems. The Acis species prefer drier soils than Leucojum species, four of them are autumn-flowering, Acis autumnalis, Acis ionica, Acis rosea and Acis valentina. Leucojum aestivum was named the county flower of Berkshire following a 2002 survey by the wild flower and it was once common in the Loddon Valley, hence its alternative name of the Loddon Lily
34.
Acis (plant)
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Acis is a genus of perennial, herbaceous and bulbous plants in the Amaryllis family. The genus consists of nine species distributed in Europe and Northern Africa, Acis was first differentiated from the genus Leucojum by Richard Anthony Salisbury in The Paradisus Londinensis in 1807. Salisbury did not explain the origin of the name Acis beyond describing it as a poetic title and it may refer to the myth of Acis and Galatea. Later botanists did not accept the distinction between Leucojum and Acis, the genus was reinstated in 2004, after it was determined on morphological and molecular grounds that the two genera were distinct. As of November 2014, the World Checklist of Selected Plant Families accepts nine species, most formerly placed in Leucojum, Central Mediterranean Acis fabrei Lledó – France Acis ionica Bareka, Kamari & Phitos – S. W. Albania to W. Greece Acis longifolia J. Gay ex M. Roem, – Corsica Acis nicaeensis Lledó, A. P. Davis & M. B. Crespo – S. E. France Acis rosea Sweet – Corsica, Sardinia Acis tingitana Lledó, A. P. Davis & M. B. Crespo – Morocco Acis trichophylla G. Don – Central & S. Portugal, S. Spain, Morocco Acis valentina Lledó, A. P. Davis & M. B. Crespo – E, spain The species Acis autumnalis has gained the Royal Horticultural Societys Award of Garden Merit
35.
Monocot
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Monocotyledons, commonly referred to as monocots, are flowering plants whose seeds typically contain only one embryonic leaf, or cotyledon. However, molecular research has shown that while the monocots form a monophyletic group or clade. Monocots have almost always recognized as a group, but with various taxonomic ranks. The APG III system of 2009 recognises a clade called monocots, the monocots include about 60,000 species. The largest family in this group by number of species are the orchids, about half as many species belong to the true grasses, which are economically the most important family of monocots. In agriculture the majority of the biomass produced comes from monocots and these include not only major grains, but also forage grasses, sugar cane, and the bamboos. Other economically important monocot crops include various palms, bananas, gingers and their relatives, turmeric and cardamom, asparagus and the onions and garlic family. Additionally most of the bulbs, plants cultivated for their blooms, such as lilies, daffodils, irises, amaryllis, cannas, bluebells. The monocots or monocotyledons have, as the name implies, a single cotyledon, or embryonic leaf, from a diagnostic point of view the number of cotyledons is neither a particularly useful characteristic, nor is it completely reliable. Nevertheless, monocots are sufficiently distinctive that there has rarely been disagreement as to membership of this group, however, morphological features that reliably characterise major clades are rare. Thus monocots are distinguishable from other angiosperms both in terms of their uniformity and diversity, although largely herbaceous, some arboraceous monocots reach great height, length and mass. The latter include agaves, palms, pandans, and bamboos and this creates challenges in water transport that monocots deal with in various ways. Some such as species of Yucca develop anomalous secondary growth, while palm trees, the axis undergoes primary thickening, that progresses from internode to internode, resulting in a typical inverted conical shape of the basal primary axis. The limited conductivity also contributes to limited branching of the stems, despite these limitations a wide variety of adaptive growth forms has resulted from epiphytic orchids and bromeliads to submarine Alismatales and mycotrophic Burmanniaceae and Triuridaceae. Other monocots, particularly Poales have adopted a life form. Leaves The cotyledon, the primordial Angiosperm leaf consists of a proximal leaf base or hypophyll, in moncots the hypophyll tends to be the dominant part in contrast to other angiosperms. Mature monocot leaves are narrow and linear, forming a sheathing around the stem at its base. There is usually only one leaf per node because the leaf base encompasses more than half the circumference, the evolution of this monocot characteristic has been attributed to developmental differences in early zonal differentiation rather than meristem activity
36.
Perianth
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The perianth is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx and the corolla. The term perianth is derived from the Greek περί, peri, meaning around, in the mosses and liverworts, the perianth is the sterile tubelike tissue that surrounds the female reproductive structure. When the perianth is in two whorls, it is described as biseriate, while the calyx may be green, it may also be brightly coloured, and is then described as petaloid. When the undifferentiated tepals resemble petals, they are referred to as petaloid, as in petaloid monocots. Since they include Liliales, a name is lilioid monocots. The corolla and petals have a role in attracting pollinators, when the corolla consists of separate tepals the term apotepalous is used, or syntepalous if the tepals are fused to one another. The petals may be united to form a tubular corolla, if either the petals or sepals are entirely absent, the perianth can be described as being monochlamydeous. Both sepals and petals may have stomata and veins, even if vestigial, in some taxa, for instance some magnolias and water lilies the perianth is arranged in a spiral on nodes, rather than whorls. Flowers with spiral perianths tend to also be those with undifferentiated perianths, an additional structure in some plants is the corona, a ring or set of appendages of adaxial tissue arising from the corolla or the outer edge of the stamens. It is often positioned where the corolla lobes arise from the corolla tube, the pappus of Asteraceae, considered to be a modified calyx, is also called a corona if it is shaped like a crown. The dictionary definition of perianth at Wiktionary
37.
Cataphyll
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In plant morphology, a cataphyll is a reduced, small leaf. Many plants have true leaves which perform the majority of photosynthesis, and cataphylls that are modified to perform other specialized functions. Cataphylls include bracts, bracteoles, and bud scales, as well as any small leaves that resemble scales, some cataphylls have a primary function other than photosynthesis. The functions of such as bud scales may be short-lived. From the Greek Ancient Greek, κατά, down, Ancient Greek, φύλλον, some kinds of cataphylls perform a transient function, after which they die and may be shed. Those that are shed early are said to be caducous, but that term can apply to any organ that is shed early, not only leaves, for example, many Geraniums have caducous stamens. The sepals of Papaver species are shed during the opening of the petals. Many other forms of cataphylls, such as spines, are persistent. Examples of various kinds of cataphylls include bud-scales, bulb-scales, corm-scales, rhizome-scales, cotyledons, scaly bracts, each of these occurs in various forms and contexts, for example, bud-scales occur on various kinds of leaf or branch buds as well as on flower buds. They begin as leaf rudiments and many kinds accumulate nutrient materials for storage, some, such as the cotyledons of many legumes, conifers, and cucurbits, even develop chlorophyll and perform the first photosynthesis for the germinating plant. It also is a matter of context and preference whether one regards any particular kind of spine as a cataphyll or not, the terminology for glochids in particular is confusing, as they are variously and arbitrarily referred to as spines, bristles and more. Morphologically only spines could strictly speaking be cataphylls, because the others are not leaves, like bulb-scales, corm-scales are largely the basal parts of the photosynthetic leaves that show above ground. Some species of plants, such as some Lapeirousias also produce cataphyllous leaves that act as practically nothing more than tunic leaves for the corm. Unlike bulb-scales however, the tunic has no significant storage function
38.
Glossary of leaf morphology
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The following is a defined list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple or compound, the edge of the leaf may be regular or irregular, may be smooth or bearing hair, bristles or spines. For more terms describing other aspects of leaves besides their overall morphology see the leaf article, leaves of most plants include a flat structure called the blade or lamina, but not all leaves are flat, some are cylindrical. Leaves may be simple, with a leaf blade, or compound. In flowering plants, as well as the blade of the leaf, there may be a petiole and stipules, leaf structure is described by several terms that include, Being one of the more visible features, leaf shape is commonly used for plant identification. Edge and margin are both interchangeable in the sense that they refer to the perimeter of a leaf. Leaves may also be folded or rolled in various ways, the folding of leaves within a bud is vernation, ptyxis is the folding of an individual leaf in a bud
39.
Convergent evolution
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Convergent evolution is the independent evolution of similar features in species of different lineages. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups, the cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is an example, as flying insects, birds. Functionally similar features that have arisen through convergent evolution are analogous, whereas homologous structures or traits have a common origin, bird, bat and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits, convergent evolution is similar to but different from parallel evolution. Many instances of convergent evolution are known in plants, including the development of C4 photosynthesis, seed dispersal by fleshy fruits adapted to be eaten by animals. In morphology, analogous traits arise when different species live in similar ways and/or a similar environment, when occupying similar ecological niches similar problems can lead to similar solutions. The British anatomist Richard Owen was the first to identify the difference between analogies and homologies. In biochemistry, physical and chemical constraints on mechanisms have caused some active site arrangements such as the triad to evolve independently in separate enzyme superfamilies. In his 1989 book Wonderful Life, Stephen Jay Gould argued that if one could rewind the tape of life the same conditions were encountered again, evolution could take a very different course. In cladistics, a homoplasy is a trait shared by two or more taxa for any other than that they share a common ancestry. Taxa which do share ancestry are part of the same clade, homoplastic traits caused by convergence are therefore, from the point of view of cladistics, confounding factors which could lead to an incorrect analysis. In some cases, it is difficult to tell whether a trait has been lost and then re-evolved convergently, or whether a gene has simply been switched off, such a re-emerged trait is called an atavism. From a mathematical standpoint, a gene has a steadily decreasing probability of retaining potential functionality over time. When two species are similar in a character, evolution is defined as parallel if the ancestors were also similar. When the ancestral forms are unspecified or unknown, or the range of traits considered is not clearly specified, the enzymology of proteases provides some of the clearest examples of convergent evolution. These examples reflect the intrinsic chemical constraints on enzymes, leading evolution to converge on equivalent solutions independently and repeatedly, serine and cysteine proteases use different amino acid functional groups as a nucleophile. In order to activate that nucleophile, they orient an acidic, the chemical and physical constraints on enzyme catalysis have caused identical triad arrangements to evolve independently more than 20 times in different enzyme superfamilies
40.
Scape (botany)
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In botany, a scape is a long internode forming the basal part or the whole of a peduncle. Typically it takes the form of a long, leafless flowering stem rising directly from a bulb, rhizome, the scapes of scallions, chives, garlic chives, and garlic are used as vegetables. The word scape, as used in botany, is vague and arbitrary. Other authorities refer to the scape rising directly from the ground, for example, A leafless floral axis or peduncle arising from the ground, as in Cyclamen. The modern trend is towards usefully distinguishing the definition of scape from those of related and it now is rarely used for such objects as stems or inflorescences in general. However, it is not easy to find coherent and fully general definitions, typical examples from authoritative online sources include the following, a peduncle arising at or beneath the surface of the ground in an acaulescent plant. A leafless stalk in plants that arises from a rosette of leaves, all those definitions are descriptive, but morphologically vacuous. In contrast, a botanical publication puts the matter plainly in a key to Eriogonum. Botanically, any structure is practically of necessity an internode. In the purest sense, that of a stem without leaves or branches. It might comprise an entire peduncle with just one flower or just the basal internode of a peduncle and this is in contrast to the typical compound peduncle, which morphologically speaking is derived from a branch, or from an entire shoot. A single scape may bear a single flower or many, depending on the species, when it bears more than one flower, there is the terminal part of an inflorescence on top, as in Amaryllis. Compare this with say, the peduncle of Agave, which sensu stricto, is not a scape, Scapes are found on plants of many families, including Amaryllidaceae, Balsaminaceae, Liliaceae, Papaveraceae, Droseraceae, and Violaceae
41.
Inflorescence
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An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the part of the shoot of seed plants where flowers are formed. Inflorescence can also be defined as the portion of a plant that bears a cluster of flowers in a specific pattern. The stem holding the whole inflorescence is called a peduncle and the major axis holding the flowers or more branches within the inflorescence is called the rachis, the stalk of each single flower is called a pedicel. A flower that is not part of an inflorescence is called a solitary flower, any flower in an inflorescence may be referred to as a floret, especially when the individual flowers are particularly small and borne in a tight cluster, such as in a pseudanthium. The fruiting stage of an inflorescence is known as an infructescence, inflorescences may be simple or complex. The rachis may be one of several types, including Single, Composite, Umbel and these terms are general representations as plants in nature can have a combination of types. Inflorescences usually have modified shoots foliage different from the part of the plant. Considering the broadest meaning of the term, any leaf associated with an inflorescence is called a bract. A bract is usually located at the node where the stem of the inflorescence forms, joined to the main stem of the plant. They serve a variety of functions which include attracting pollinators and protecting young flowers, according to the presence or absence of bracts and their characteristics we can distinguish, Ebracteate inflorescences, No bracts in the inflorescence. Bracteate inflorescences, The bracts in the inflorescence are very specialised, sometimes reduced to small scales and this use is not technically correct, as, despite their normal appearance, these leaves are considered, in fact, bracts, so that leafy inflorescence is preferable. Leafy-bracted inflorescences, Intermediate between bracteate and leafy inflorescence, if many bracts are present and they are strictly connected to the stem, like in the family Asteraceae, the bracts might collectively be called an involucre. If the inflorescence has a unit of bracts further up the stem. Plant organs can grow according to two different schemes, namely monopodial or racemose and sympodial or cymose, the terminal bud keeps growing and forming lateral flowers. A terminal flower is never formed, the terminal bud forms a terminal flower and then dies out. Other flowers then grow from lateral buds, indeterminate and determinate inflorescences are sometimes referred to as open and closed inflorescences respectively. In an indeterminate inflorescence there is no true terminal flower and the stem usually has a rudimentary end, in many cases the last true flower formed by the terminal bud straightens up, appearing to be a terminal flower
42.
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
43.
Spathe
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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
44.
Glossary of botanical terms
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This glossary is incomplete, you can help by expanding it, you can also help by adding illustrations that assist an understanding of the terms. Ab- A prefix meaning from, away from, or outside of, abaxial The surface of an organ facing away from the axis, e. g. the lower surface of a lateral organ such as a leaf or petal. Abort To abandon development of a structure or organ, abscission shedding of an organ that is mature or aged, e. g. a ripe fruit or an old leaf. Abscission zone a specialised layer of tissue formed, for example, acaulescent An adjective descriptive of a plant that has no apparent stem, or at least none visible above ground. Examples include some species of Agave, Oxalis and Attalea, accrescent Increasing in size with age, such as a calyx that continues to grow after the corolla has fallen, for example in Physalis peruviana. -aceae The suffix added to the stem of a name to form the name of a family. Achene A dry 1-seeded indehiscent fruit, e. g. in the genus Ranunculus, acropetal Moving from roots to leaves, e. g. of molecular signals in plants. Acrophyll The regular leaves of a plant, produced above the base. Acrostichoid covering the entire surface of the frond, usually densely so. Actino- A prefix that indicates a radial form, actinodromous palmate or radially arranged venation with three or more primary veins arising from at or near the base of the leaf, the primary veins reaching the margin or not. Actinomorphic regular, radially symmetrical, may be bisected into similar halves in at least two planes. Applies e. g. to steles and flowers in which the segments within each whorl are alike in size and shape, compare regular, contrast with asymmetrical, irregular. Aculeate Armed with prickles, e. g. the stem of a rose, acuminate Tapering gradually to a point. Acute Sharply pointed, converging edges making an angle of less than 90°, ad- A prefix meaning near or towards. Adaxial The surface of an organ facing towards the axis, e. g. the upper surface of an organ such as a leaf or petal. Adnate grown or fused to an organ of a different kind, especially along a margin, e. g. a stamen fused to a petal, cf. connate. Adventitious A structure produced in a position, e. g. an adventitious bud produced from a stem rather than from the axil of a leaf. Aerial Of the air, growing or borne above the surface of the ground, aestivation The arrangement of sepals and petals or their lobes in an unexpanded flower bud, cf. vernation, the arrangement of leaves in a bud. aff
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Pedicel (botany)
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A pedicel is a stem that attaches a single flower to the inflorescence. In the absence of a pedicel, the flowers are described as sessile, pedicel is also applied to the stem of the infructescence. The stem or branch from the stem of the inflorescence that holds a group of pedicels is called a peduncle
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Stamen
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The stamen is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium, a stamen typically consists of a stalk called the filament and an anther which contains microsporangia. Most commonly anthers are two-lobed and are attached to the filament either at the base or in the area of the anther. The sterile tissue between the lobes is called the connective, a pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The stamens in a flower are called the androecium. The androecium can consist of as few a one-half stamen as in Canna species or as many as 3,482 stamens which have been counted in Carnegiea gigantea, the androecium in various species of plants forms a great variety of patterns, some of them highly complex. It surrounds the gynoecium and is surrounded by the perianth, a few members of the family Triuridaceae, particularly Lacandonia schismatica, are exceptional in that their gynoecia surround their androecia. Stamen is the Latin word meaning thread, depending on the species of plant, some or all of the stamens in a flower may be attached to the petals or to the floral axis. They also may be free-standing or fused to one another in different ways, including fusion of some. The filaments may be fused and the free, or the filaments free. Rather than there being two locules, one locule of a stamen may fail to develop, or alternatively the two locules may merge late in development to give a single locule, a typical anther contains four microsporangia. The microsporangia form sacs or pockets in the anther, the two separate locules on each side of an anther may fuse into a single locule. Each microsporangium is lined with a tissue layer called the tapetum. These undergo meiosis to form haploid spores, the spores may remain attached to each other in a tetrad or separate after meiosis. Each microspore then divides mitotically to form an immature microgametophyte called a pollen grain, the pollen is eventually released when the anther forms openings. These may consist of longitudinal slits, pores, as in the family, or by valves. More commonly, mature pollen grains separate and are dispensed by wind or water, pollinating insects, pollen of angiosperms must be transported to the stigma, the receptive surface of the carpel, of a compatible flower, for successful pollination to occur. After arriving, the pollen grain typically completes its development and it may grow a pollen tube and undergoing mitosis to produce two sperm nuclei
low, northern wind; fall snow;
