Information AboutFlower |
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'' bears bright orange flowers. The roots of this plant are poisonous.]] A flower, (< Old French ''flo(u)r''< Latin ''florem''<''flos''), also known as a '''bloom''' or '''blossom''', is the reproductive structure found in Flowering Plant s ( Plant s of the division ''Magnoliophyta'', also called sperms). The flower structure contains the plant's reproductive organs, and its function is to produce Seed s through Sexual Reproduction . 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. After Fertilization , portions of the flower develop into a Fruit containing the seeds. Flower anatomy Flowering plants are ''heterosporangiate'' (producing two types of reproductive Spore s). The Pollen (male spores) and ovules (female spores) are produced in different Organs , but these are together in a ''bisporangiate strobilus'' that is the typical flower. A flower is regarded as a modified Stem (Eames, 1961) with shortened internodes and bearing, at its nodes, structures that may be highly modified Leaves . In essence, a flower structure forms on a modified shoot or ''axis'' with an apical Meristem that does not grow continuously (growth is ''determinate''). The stem is called a pedicel, the end of which is the '''torus''' or '''receptacle'''. The parts of a flower are arranged in whorls on the torus. The four main parts or whorls (starting from the base of the flower or lowest node and working upwards) are as follows:
Although the floral structure described above is considered the "typical" structural plan, plant species show a wide variety of modifications from this plan. These modifications have significance in the evolution of flowering plants and are used extensively by botanists to establish relationships among plant species. For example, the two subclasses of flowering plants may be distinguished by the number of floral organs in each whorl: Dicotyledon s typically having 4 or 5 organs (or a multiple of 4 or 5) in each whorl and Monocotyledon s having three or some multiple of three. The number of carpels in a compound pistil may be only two, or otherwise not related to the above generalization for monocots and dicots. In the majority of species individual flowers have both pistils and stamens as described above. These flowers are described by botanists as being perfect, '''bisexual''', or ''''''''. However, where unisexual male and female flowers appear on the same plant, the species is considered ''''' Monoecious '''''. 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 the ). flower showing six stamens and the stigma and style of a pistil]] Additional discussions on floral modifications from the basic plan are presented in the articles on each of the basic parts of the flower. In those species that have more than one flower on an axis, the collection of flowers is termed an Inflorescence . In this sense, care must be exercised in considering what is a ''flower''. In botanical terminology, a single Daisy or Sunflower for example, is not a flower but a flower '''head'''—an inflorescence comprised of numerous small flowers (sometimes called florets). Each small flower may be anatomically as described above. Floral formula A floral formula is a way to represent the structure of a flower using specific letters, numbers, and symbols. Typically, a general formula will be used to represent the flower structure of a plant Family rather than a particular species. The following representations are used: Ca = calyx (sepal whorl; e.g. Ca5 = 5 sepals) Co = corolla (petal whorl; e.g., Co3(x) = petals some multiple of three ) Z = add if ''zygomorphic'' (e.g., CoZ6 = zygomorphic with 6 petals) A = ''androecium'' (whorl of stamens; e.g., A∞ = many stamens) G = ''gynoecium'' (carpel or carpels; e.g., G1 = monocarpous) ''x'' - to represent a "variable number" ∞ - to represent "many" A floral formula would appear something like this: :Ca5Co5A10 - ∞G1 Several other symbols are used that will have to await drawings to illustrate here (see {Link without Title} ). Flower function ]] The function of a flower is to mediate the union of male and female gametes. The process is termed Pollination . Many flowers are dependent upon the wind to move pollen between flowers of the same species. Others rely on animals (especially insects) to accomplish this feat. The period of time during which this process can take place (the flower is fully expanded and functional) is called '''anthesis'''. Many flowers in nature have evolved to attract animals to pollinate the flower, the movements of the pollinating agent contributing to the opportunity for genetic recombinations within a dispersed plant population. Flowers that are insect-pollinated are called ''entomophilous'' (literally "insect-loving"). Flowers commonly have glands called '''nectaries''' on their various parts that attract these animals. s, that show pollinators where to look for nectar; they may be visible to us or only under Ultraviolet light, which is visible to bees and some other insects. Flowers also attract pollinators by Scent . Many of their scents are pleasant to our sense of smell, but not all. Some plants, such as '' Rafflesia '', the Titan Arum , and the North American Pawpaw (''Asimina triloba''), are pollinated by Flies , so produce a scent Imitating Rotting Meat . In any case, pollinators are attracted to the plant, perhaps in search of Nectar , which they eat. The arrangement of the stamens ensures that pollen grains are transferred to the bodies of the pollinator. In gathering nectar from many flowers of the same species, the pollinator transfers pollen between all of the flowers it visits. The flowers of other species are pollinated by the wind (for example, Grasses ); they have no need to attract pollinators and therefore tend not to be "showy". Wind-pollinated flowers are referred to as ''anemophilous''. Whereas the pollen of entomophilous flowers tends to be large-grained, sticky, and rich in Protein (another "reward" for pollinators), anemophilous flower pollen is usually small-grained, very light, and of little nutritional value to Insect s, though it may still be gathered in times of dearth. Honeybees and bumblebees actively gather anemophilous corn ( Maize ) pollen, though it is of little value to them. There is much confusion about the role of flowers in allergies. For example the showy and entomophilous Goldenrod (''Solidago'') is frequently blamed for Respiratory Allergies , of which it is innocent, since its pollen cannot be airborne. Instead the Allergen is usually the pollen of the contemporary bloom of anemophilous Ragweed (''Ambrosia''), which can drift for many kilometers. Flowers in gardening and horticulture ''Main and related articles at'': Gardening , Horticulture , List Of Flowers , and Floristry Flowers in the arts being Pollinated by a bee.]] The great variety of delicate and beautiful flowers has inspired the works of many poets, especially from the Romantic era. Famous examples include and William Wordsworth 's '' I Wandered Lonely As A Cloud '' and William Blake 's ''Ah! Sun-Flower'':
The Roman goddess of flowers, gardens, and the season of Spring is Flora . The Greek goddess of spring, flowers and nature is Chloris . Flowers in everyday life 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, florists sell flowers for a wide range of events and functions that, cumulatively, encompass one's lifetime:
Florists depend on an entire network of commercial growers and shippers to support this trade. To get flowers that are out of season in their country, florists contact wholesalers who have direct connections with growers in other countries to provide those flowers. Flowers as symbols Many flowers have important Symbolic meanings in Western culture. The practice of assigning meanings to flowers is known as Floriography . Some of the more common examples include:
Flowers within art are also representative of the female genitalia, as seen in the works of artists such as Georgia O'Keefe , Imogen Cunningham , and Judy Chicago . Flowers have been used by the well-known florist Imogen Stone to create beautiful arrangements and bouquets. References
See also Galleries
Types of Flowers External links
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