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| | [[Image:Phalaenopsis_%28aka%29.jpg|300px|thumb|A ''[[Phalaenopsis]]'' flower]] | | [[Image:Phalaenopsis_%28aka%29.jpg|300px|thumb|A ''[[Phalaenopsis]]'' flower]] |
| | [[Image:Blume mit Schmetterling und Biene 1uf.JPG|thumb|300px| [[Rudbeckia fulgida]]]] | | [[Image:Blume mit Schmetterling und Biene 1uf.JPG|thumb|300px| [[Rudbeckia fulgida]]]] |
| | + | Flowers are unique structures housing reproductive parts of plants belonging to the angiosperm branch of the plant family. All flowers share similar underlying features allowing them to produce seed, but there are a huge variety of shapes, colors, sizes and fragrances. Cultivation has led to additional varieties and diversity thanks to selective breeding. |
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| | + | ==Structure and function== |
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| | + | ===Flower parts=== |
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| | + | ===Ornamental attractions=== |
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| | + | ===Life cycle=== |
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| | + | <gallery> |
| | + | Image:placeholder.jpg| Bud |
| | + | Image:placeholder.jpg| Flower |
| | + | Image:placeholder.jpg| Fruit |
| | + | </gallery> |
| | + | |
| | + | ===Different structures=== |
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| | + | |
| | + | <gallery> |
| | + | Image:placeholder.jpg| Flowerhead |
| | + | Image:placeholder.jpg| Iris |
| | + | Image:placeholder.jpg| Bracts |
| | + | Image:placeholder.jpg| Spathe |
| | + | Image:placeholder.jpg| Spurred flower |
| | + | </gallery> |
| | + | |
| | + | ===Inflorescences=== |
| | + | |
| | + | |
| | + | <gallery> |
| | + | Image:placeholder.jpg| Solitary |
| | + | Image:placeholder.jpg| Cluster |
| | + | Image:placeholder.jpg| Flowerhead |
| | + | Image:placeholder.jpg| Umbel |
| | + | Image:placeholder.jpg| Cyme |
| | + | Image:placeholder.jpg| Spike |
| | + | Image:placeholder.jpg| Raceme |
| | + | Image:placeholder.jpg| Corymb |
| | + | Image:placeholder.jpg| Panicle |
| | + | </gallery> |
| | + | |
| | + | ===Shape=== |
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| | + | |
| | + | <gallery> |
| | + | Image:placeholder.jpg| Cross-shaped (cruciform) |
| | + | Image:placeholder.jpg| Star-shaped (stellate) |
| | + | Image:placeholder.jpg| Saucer-shaped |
| | + | Image:placeholder.jpg| Cup-shaped |
| | + | Image:placeholder.jpg| Bell-shaped (campanulate) |
| | + | Image:placeholder.jpg| Tubular |
| | + | Image:placeholder.jpg| Funnel-shaped |
| | + | Image:placeholder.jpg| Salverform |
| | + | Image:placeholder.jpg| Trumpet-shaped |
| | + | Image:placeholder.jpg| Rosette |
| | + | Image:placeholder.jpg| Pompon |
| | + | Image:placeholder.jpg| Pea-like |
| | + | Image:placeholder.jpg| Pitcher-shaped |
| | + | Image:placeholder.jpg| Slipper-shaped |
| | + | </gallery> |
| | + | |
| | + | ===Petal arrangement=== |
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| | + | |
| | + | <gallery> |
| | + | Image:placeholder.jpg| Single |
| | + | Image:placeholder.jpg| Semi-double |
| | + | Image:placeholder.jpg| Double |
| | + | </gallery> |
| | + | |
| | + | ===Habits=== |
| | + | |
| | + | <gallery> |
| | + | Image:placeholder.jpg| Erect |
| | + | Image:placeholder.jpg| Horizontal |
| | + | Image:placeholder.jpg| Nodding |
| | + | Image:placeholder.jpg| Pendant |
| | + | </gallery> |
| | + | |
| | + | ===Colors=== |
| | + | |
| | + | <gallery> |
| | + | Image:placeholder.jpg| Self-colored |
| | + | Image:placeholder.jpg| Bicolored |
| | + | Image:placeholder.jpg| Picotee |
| | + | Image:placeholder.jpg| Striped |
| | + | </gallery> |
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| | A '''flower''', (<[[Old French]] ''flo(u)r''<[[Latin]] ''florem''<''flos''), also known as a '''bloom''' or '''blossom''', is the [[reproduction|reproductive]] structure found in [[flowering plant]]s ([[plant]]s of the division ''Magnoliophyta'', also called angiosperms). The flower's structure contains the plant's reproductive organs, and its function is to produce [[seed]]s. After [[fertilization]], portions of the flower develop into a [[fruit]] containing the seeds. For the higher plants, seeds are the next generation, and serve as the primary means by which individuals of a species are dispersed across the landscape. The grouping of flowers on a plant is called the [[inflorescence]]. | | A '''flower''', (<[[Old French]] ''flo(u)r''<[[Latin]] ''florem''<''flos''), also known as a '''bloom''' or '''blossom''', is the [[reproduction|reproductive]] structure found in [[flowering plant]]s ([[plant]]s of the division ''Magnoliophyta'', also called angiosperms). The flower's structure contains the plant's reproductive organs, and its function is to produce [[seed]]s. After [[fertilization]], portions of the flower develop into a [[fruit]] containing the seeds. For the higher plants, seeds are the next generation, and serve as the primary means by which individuals of a species are dispersed across the landscape. The grouping of flowers on a plant is called the [[inflorescence]]. |
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| | Some flowers with both stamens and a pistil are capable of self-fertilization, which does increase the chance of producing seeds but limits genetic variation. The extreme case of self-fertilization occurs in flowers that always self-fertilize, such as many [[dandelion]]s. Conversely, many species of plants have ways of preventing self-fertilization. Unisexual male and female flowers on the same plant may not appear or mature at the same time, or pollen from the same plant may be incapable of fertilizing its ovules. The latter flower types, which have chemical barriers to their own pollen, are referred to as self-sterile or self-incompatible (see also: [[Plant sexuality]]). | | Some flowers with both stamens and a pistil are capable of self-fertilization, which does increase the chance of producing seeds but limits genetic variation. The extreme case of self-fertilization occurs in flowers that always self-fertilize, such as many [[dandelion]]s. Conversely, many species of plants have ways of preventing self-fertilization. Unisexual male and female flowers on the same plant may not appear or mature at the same time, or pollen from the same plant may be incapable of fertilizing its ovules. The latter flower types, which have chemical barriers to their own pollen, are referred to as self-sterile or self-incompatible (see also: [[Plant sexuality]]). |
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| − | ==Evolution==
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| − | While land plants have existed for about 425 million years, the first ones [[plant sexuality|reproduced]] by a simple adaptation of their aquatic counterparts: [[spore]]s. In the sea, plants -- and some animals -- can simply scatter out little living copies of themselves to float away and grow elsewhere. This is how early plants, such as the modern fern, are thought to have reproduced. But plants soon began protecting these copies to deal with drying out and other abuse which is even more likely on land than in the sea. The protection became the [[seed]]...but not, yet, flowers. Early seed-bearing plants include the [[ginkgo]], [[conifer]]s (like pines), and [[fir]] trees. But the first fossil proof of actual flowers appears only 130 million years ago.
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| − | Unfortunately, there is no fossil evidence of exactly how flowers evolved; the evidence has them springing in advanced form into the fossil record. This was recognized almost immediately during the development of evolution theory, the strange appearance of flowers in the fossil record being called by [[Charles Darwin]] the Abominable Mystery.
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| | [[Image:Flores.gif|200px|thumb|right|Various flower colors and shapes]] | | [[Image:Flores.gif|200px|thumb|right|Various flower colors and shapes]] |
| | [[Image:Syrphid fly on Virginia Bluebells.jpg|thumb|200px|A [[Syrphid fly]] on a [[Virginia Bluebell]]]] | | [[Image:Syrphid fly on Virginia Bluebells.jpg|thumb|200px|A [[Syrphid fly]] on a [[Virginia Bluebell]]]] |
| − | The general assumption is that the function of flowers, from the start, was to involve other animals in the reproduction process. Pollen can be scattered without bright colors and obvious shapes, which would therefore be a liability, using the plant's resources, unless they provide some other benefit. One proposed reason for the sudden, fully developed appearance of flowers is that they evolved in an isolated setting like an island, or chain of islands, where the plants bearing them were able to develop a highly specialized relationship with some specific animal (a wasp, for example), the way many island species develop today. This symbiotic relationship, with a hypothetical wasp bearing pollen from one plant to another much the way [[fig wasp]]s do today, could have eventually resulted in both the plant(s) and their partners developing a high degree of specialization. [[Island genetics]] is believed to be a common source of speciation, especially when it comes to radical adaptations which seem to have required inferior transitional forms. Note that the wasp example is not incidental; bees, apparently evolved specifically for symbiotic plant relationships, are descended from wasps.
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| − | Likewise, most [[fruit]] used in plant reproduction comes from the enlargement of parts of the flower. This fruit is frequently a tool which depends upon animals wishing to eat it, and thus scattering the seeds it contains.
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| − | While many such [[symbiotic relationship]]s remain too fragile to survive competition with mainla
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| − | nd animals and spread, flowers proved to be an unusually effective means of production, spreading (whatever their actual origin) to become the dominant form of land plant life.
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| − | While there is only hard proof of such flowers existing about 130 million years ago, there is some circumstantial evidence that they did exist up to 250 million years ago. A chemical used by plants to defend their flowers, [[oleanane]], has been detected in fossil plants that old, including [[gigantopterid]]s[http://www.sciencedaily.com/releases/2001/04/010403071438.htm], which evolved at that time and bear many of the traits of modern, flowering plants, though they are not known to be flowering plants themselves, because only their stems and prickles have been found preserved in detail; one of the earliest examples of [[petrified wood|petrification]].
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| − | The similarity in [[leaf]] and [[stem]] structure can be very important, because flowers are genetically just an adaptation of normal leaf and stem components on plants, a combination of genes normally responsible for forming new shoots[http://unisci.com/stories/20012/0615015.htm]. The most primitive flowers are thought to have had a variable number of flower parts, often separate from (but in contact with) each other. The flowers would have tended to grow in a spiral pattern, to be [[bisexual]] (in plants, this means both male and female parts on the same flower), and to be dominated by the [[ovary (plants)|ovary]] (female part). As flowers grew more advanced, some variations developed parts fused together, with a much more specific number and design, and with either specific sexes per flower or plant, or at least "ovary inferior".
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| − | Flower evolution continues to the present day; modern flowers have been so profoundly influenced by humans that many of them cannot be pollinated in nature. Many modern, domesticated flowers used to be simple weeds, which only sprouted when the ground was disturbed. Some of them tended to grow with human crops, and the prettiest did not get plucked because of their beauty, developing a dependence upon and special adaptation to human affection[http://www.livescience.com/othernews/050526_flower_power.html].
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| − | == Development ==
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| − | The molecular control of floral organ identity determination is fairly well understood. In a simple model, three gene activities interact in a combinatorial manner to determine the developmental identities of the organ primordia within the floral [[meristem]]. These gene functions are called A, B and C-gene functions. In the first floral whorl only A-genes are expressed, leading to the formation of sepals. In the second whorl both A- and B-genes are expressed, leading to the formation of petals. In the third whorl, B and C genes interact to form stamens and in the center of the flower C-genes alone give rise to carpels. The model is based upon studies of [[homeotic]] mutants in Arabidopsis thaliana and snapdragon, Antirrhinum majus. For example, in a loss of B-gene function mutant flower we get sepals in the first whorl as usual, but also in the second whorl (the B-function lost that is needed for petal development). In the third whorl the lack of B function but presence of C-function mimics the fourth whorl, leading to the formation of carpels also in the third whorl. See also [[The ABC Model of Flower Development]].
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| − | Most genes central in this model belong to the [[MADS-box]] genes and are [[transcription factors]] that regulate the expression of the genes specific for each floral organ.
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| − | === Flowering transition ===
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| − | The [[transition]] to flowering is one of the major phase changes that a plant makes during its life cycle. The transition must take place at a time that will ensure maximal [[reproductive]] success. To meet these needs a plant is able to interpret important endogenous and environmental cues such as changes in [[plant hormones]] levels and seasonable [[temperature]] and [[photoperiod]]changes. Many perennial and most biennial plants require [[vernalization]] to flower. The molecular interpretation of these signals throu
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| − | gh genes such as CONSTANS and FLC ensures that flowering occurs at a time that is favorable for [[fertilization]] and the formation of [[seeds]]<ref>Ausin et al (2005), Environmental regulation of flowering. Int J Dev Biol. 2005;49(5-6):689-705</ref>. Flower formation is initiated at the ends of stems, and involves a number of different physiological and morphological changes. The first step is the transformation of the vegetative stem primordia into floral primordia. This occurs as biochemical changes take place to change cellular differentiation of leaf, bud and stem tissues into tissue that will grow into the reproductive organs. Growth of the central part of the stem tip stops or flattens out and the sides develop protuberances in a whorled or spiral fashion around the outside of the stem end. These protuberances develop into the sepals, petals, stamens, and carpels. Once this process begins, in most plants, it cannot be reversed and the stems develop flowers, even if the initial start of the flower formation event was dependent of some environmental cue. Once the process begins, even if that cue is removed the stem will continue to develop a flower.
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| − | ==Uses by humans==
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| − | ===In everyday life===
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| − | [[Image:boysmellsflower.jpg|thumb|200px|Flowers are beloved for their various fragrances]]
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| − | In modern times, people have sought ways to cultivate, buy, wear, or just be around flowers and blooming plants, partly because of their agreeable [[smell]]. Around the world, people use flowers for a wide range of events and functions that, cumulatively, encompass one's lifetime:
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| − | * For new births or [[Christening]]s
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| − | * As a corsage or boutonniere to be worn at social functions or for holidays
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| − | * For [[wedding]] flowers for the bridal party, and decorations for the hall
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| − | * As brightening decorations within the home
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| − | * As a gift of remembrance for bon voyage parties, welcome home parties, and "thinking of you" gifts
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| − | * For [[funeral]] flowers and expressions of [[sympathy]] for the grieving
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| − | People therefore grow flowers around their homes, dedicate entire parts of their living space to [[flower garden]]s, pick wildflowers, or buy flowers from [[florist]]s who depend on an entire network of commercial growers and shippers to support their trade.
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| − | ===Symbolism===
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| | [[Image:Liliumbulbiferumflowertop.jpg|thumb|200px|right|Lilies are often used to denote life or resurrection]] | | [[Image:Liliumbulbiferumflowertop.jpg|thumb|200px|right|Lilies are often used to denote life or resurrection]] |
| − | Many flowers have important [[symbol|symbolic]] meanings in Western culture. The practice of assigning meanings to flowers is known as [[floriography]]. Some of the more common examples include:
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| − | * Red [[rose]]s are given as a symbol of [[love]], beauty, and passion.
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| − | * [[Poppy|Poppies]] are a symbol of consolation in time of death. In the [[United Kingdom|UK]], [[Australia]] and [[Canada]], red poppies are worn to commemorate soldiers who have died in times of war.
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| − | * [[Iris (plant)|Irises]]/[[Lily]] are used in burials as a symbol referring to "resurrection/life". It is also associated with stars (sun) and its petals blooming/shining.
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| − | * [[Asteraceae|Daisies]] are a symbol of innocence.
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| − | Flowers within art are also representative of the female genitalia, as seen in the works of artists such as [[Georgia O'Keefe]], [[Imogen Cunningham]], [[Veronica Ruiz de Velasco]], and [[Judy Chicago]], and in fact in Asian and western classical art.
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| | === Edible flowers === | | === Edible flowers === |
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| | ===Floristry=== | | ===Floristry=== |
| − | ''Under Construction'' <br>
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| | ''Main and related articles at'': [[Floristry]], [[Flower garden]], [[Gardening]], and [[List of flowers]] | | ''Main and related articles at'': [[Floristry]], [[Flower garden]], [[Gardening]], and [[List of flowers]] |
| | Flowers can also be made into tea. Dried flowers such as chrysanthemum, rose, jasmine are infused into tea by the oriental people both for their fragrance and medical properties. Sometimes, they are also mixed with tea leaves for the added fragrance. | | Flowers can also be made into tea. Dried flowers such as chrysanthemum, rose, jasmine are infused into tea by the oriental people both for their fragrance and medical properties. Sometimes, they are also mixed with tea leaves for the added fragrance. |
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| − | ===In the arts===
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| − | [[Image:Ambrosius_Bosschaert,_the_Elder_04.jpg|thumb|200px|Flowers are common subjects of still lifes, such as this one by [[Ambrosius_Bosschaert the Elder]]]]
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| − | The great variety of delicate and beautiful flowers has inspired the works of numerous poets, especially from the 18<sup>th</sup>-19<sup>th</sup> century [[Romantic poetry|Romantic]] era. Famous examples include [[William Wordsworth]]'s ''[[I Wandered Lonely as a Cloud]]'' and [[William Blake]]'s ''Ah! Sun-Flower''.
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| − | Because of their varied and colorful appearance, flowers have long been a favorite subject of visual artists as well. Some of the most celebrated paintings from well-known painters are of flowers, such as [[Vincent van Gogh|Van Gogh]]'s [[sunflowers (series of paintings)|sunflowers]] series or [[Claude Monet|Monet]]'s water lilies.
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| − | ===Mythology===
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| − | The Roman goddess of flowers, gardens, and the season of Spring is [[Flora (goddess)|Flora]]. The Greek goddess of spring, flowers and nature is [[Chloris]].
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| − | In [[Hindu]] mythology, flowers have a significant status. [[Vishnu]], one of the three major gods in the [[Hindu]] system, is often depicted standing straight on a [[lotus]] flower[http://www.bbc.co.uk/religion/religions/hinduism/deities/vishnu.shtml]. Apart from the association with [[Vishnu]], the Hindu tradition also considers the lotus to have spiritual significance[http://www.theflowerexpert.com/content/miscellaneous/flowers-and-religion]. For example, it figures in the Hindu stories of creation[http://www.theosociety.org/pasadena/sunrise/49-99-0/ge-mrook.htm].
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| | ==References== | | ==References== |
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| | ==See also== | | ==See also== |
| − | {{commonscat|Flowers}}
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| − | {{Commons|Flower}}
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| − | {{wiktionary}}
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| | * [[Plants]] | | * [[Plants]] |
| | * [[Garden]] | | * [[Garden]] |
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| | ==External links== | | ==External links== |
| − | {{SpamD|{{cleanup-spam}}}}
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| | *[http://www.britannica.com/search?query=flower Britannica Online] Flower | | *[http://www.britannica.com/search?query=flower Britannica Online] Flower |
| − | {{SpamD|*[http://www.flowerpossibilities.com/encyclopedia.html Flower Encyclopedia]|}}
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| | *[http://www.orchidean.com/videos Orchid Videos] | | *[http://www.orchidean.com/videos Orchid Videos] |
| | *[http://www.flowers-photos.eu flowers-photos.eu] Wild flowers photos | | *[http://www.flowers-photos.eu flowers-photos.eu] Wild flowers photos |
| − | {{SpamD|*[http://www.conservatoryofflowers.org/ Conservatory of Flowers] |}}
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| | * [http://wildflower.utexas.edu/ Native Plant Information Network] | | * [http://wildflower.utexas.edu/ Native Plant Information Network] |
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