1.
Lime (fruit)
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A lime is a hybrid citrus fruit, which is typically round, lime green, 3–6 centimetres in diameter, and containing acidic juice vesicles. There are several species of trees whose fruits are called limes, including the Key lime, Persian lime, kaffir lime. Limes are an excellent source of vitamin C, and are used to accent the flavours of foods. Plants with fruit called limes have diverse origins, limes do not form a monophyletic group. Species of this genus hybridise readily, and it is only recently that genetic studies have started to light on the structure of the genus. The majority of cultivated species are in reality hybrids, produced from the citron, the mandarin, Australian limes Australian desert lime Australian finger lime Australian lime Blood lime Kaffir lime, also called a kieffer lime, makrut, or magrood, a papeda relative. This is one of three most widely produced limes globally, Key lime, also called Mexican, West Indian, or bartenders lime. This is also one of three most widely produced limes globally, musk lime, a kumquat hybrid Persian lime, with cultivars including the Tahiti and Bearss limes. This is the single most widely produced lime globally, with Mexico being the largest producer, rangpur lime, a mandarin orange – rough lemon hybrid Spanish lime, also called mamoncillo, mamón, ginep, quenepa, or limoncillo), not a citrus. Sweet lime etc. assorted citrus hybrids) including varieties called sweet lemon, sweet limetta or Mediterranean sweet lemon, lumia, Indian or Palestinian sweet lime. Limequat Note that the species known in Britain as lime trees. To prevent scurvy during the 19th century, British sailors were issued a daily allowance of citrus, such as lemon, the British sailor thus acquired the nickname, Limey because of their usage of limes. In 2013, the world production of lemons and limes was 15.42 million tonnes. Limes have higher contents of sugars and acids than do lemons, lime juice may be squeezed from fresh limes, or purchased in bottles in both unsweetened and sweetened varieties. Lime juice is used to make limeade, and as an ingredient in many cocktails, lime pickles are an integral part of Indian cuisine. South Indian cuisine is based on lime, having either lemon pickle or lime pickle is considered an essential of Onam Sadhya. In cooking, lime is valued both for the acidity of its juice and the aroma of its zest. It is an ingredient in authentic Mexican, Vietnamese and Thai dishes
2.
Morton Arboretum
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The Morton Arboretum, in Lisle, Illinois, is a public garden and outdoor museum with a library, herbarium, and program in tree research including the Center for Tree Science. Its grounds, covering 1,700 acres, include cataloged collections of trees and other living plants, gardens, the living collections include more than 4,100 different plant species, which can be referenced in an online database. In all, there are more than 200,000 cataloged plants, as a place of recreation, the Arboretum has hiking trails, roadways for driving and bicycling, a 4-acre interactive childrens garden and a 1-acre maze. The Schulenberg Prairie at the arboretum was one of the earliest prairie restoration projects in the Midwest and it is one of the largest restored prairies in the Chicago suburban area. The arboretum offers an extensive nature-entered education program for children, families, school groups, scouts, the Woodland Stewardship Program offers classroom and online courses in ecological restoration techniques. The arboretum also offers courses through the Associated Colleges of the Chicago Area. Its stated goal is to encourage the planting and conservation of trees and other plants for a greener, healthier, the arboretum was established on December 14,1922, by Joy Morton, founder of the Morton Salt Company. The arboretums first superintendent was Clarence E. Godshalk, who had received a degree in landscape design from the University of Michigan in 1921. Joy Mortons Thornhill Estate, established in 1910, formed the core of the Arboretums original area, mr. Mortons father Julius Sterling Morton had founded Arbor Day. Designed by noted Chicago architect Harry Weese, the Sterling Morton Library was constructed in 1963 and named after Sterling Morton, son of founder Joy Morton. It currently holds more than 30,000 books and magazines, as well as tens of thousands of items including prints, original art, letters, photographs, landscape plans. The Librarys Suzette Morton Davidson Special Collections includes books, artwork, historic nursery catalogs, landscape drawings, photographs, letters, maps and it also includes documents of May Theilgaard Watts, Jens Jensen, Marshall Johnson, O. C. Simonds and Donald Culross Peattie. The Sterling Morton Library is a member of the Council on Botanical and Horticultural Libraries, the 36,000 sq ft Visitor Center was built in 2004 and designed by David Woodhouse Architects
3.
Chicago
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Chicago, officially the City of Chicago, is the third-most populous city in the United States. With over 2.7 million residents, it is the most populous city in the state of Illinois, and it is the county seat of Cook County. In 2012, Chicago was listed as a global city by the Globalization and World Cities Research Network. Chicago has the third-largest gross metropolitan product in the United States—about $640 billion according to 2015 estimates, the city has one of the worlds largest and most diversified economies with no single industry employing more than 14% of the workforce. In 2016, Chicago hosted over 54 million domestic and international visitors, landmarks in the city include Millennium Park, Navy Pier, the Magnificent Mile, Art Institute of Chicago, Museum Campus, the Willis Tower, Museum of Science and Industry, and Lincoln Park Zoo. Chicagos culture includes the arts, novels, film, theater, especially improvisational comedy. Chicago also has sports teams in each of the major professional leagues. The city has many nicknames, the best-known being the Windy City, the name Chicago is derived from a French rendering of the Native American word shikaakwa, known to botanists as Allium tricoccum, from the Miami-Illinois language. The first known reference to the site of the current city of Chicago as Checagou was by Robert de LaSalle around 1679 in a memoir, henri Joutel, in his journal of 1688, noted that the wild garlic, called chicagoua, grew abundantly in the area. In the mid-18th century, the area was inhabited by a Native American tribe known as the Potawatomi, the first known non-indigenous permanent settler in Chicago was Jean Baptiste Point du Sable. Du Sable was of African and French descent and arrived in the 1780s and he is commonly known as the Founder of Chicago. In 1803, the United States Army built Fort Dearborn, which was destroyed in 1812 in the Battle of Fort Dearborn, the Ottawa, Ojibwe, and Potawatomi tribes had ceded additional land to the United States in the 1816 Treaty of St. Louis. The Potawatomi were forcibly removed from their land after the Treaty of Chicago in 1833, on August 12,1833, the Town of Chicago was organized with a population of about 200. Within seven years it grew to more than 4,000 people, on June 15,1835, the first public land sales began with Edmund Dick Taylor as U. S. The City of Chicago was incorporated on Saturday, March 4,1837, as the site of the Chicago Portage, the city became an important transportation hub between the eastern and western United States. Chicagos first railway, Galena and Chicago Union Railroad, and the Illinois, the canal allowed steamboats and sailing ships on the Great Lakes to connect to the Mississippi River. A flourishing economy brought residents from rural communities and immigrants from abroad, manufacturing and retail and finance sectors became dominant, influencing the American economy. The Chicago Board of Trade listed the first ever standardized exchange traded forward contracts and these issues also helped propel another Illinoisan, Abraham Lincoln, to the national stage
4.
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
5.
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
6.
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
7.
Malvaceae
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Malvaceae, or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of this family include okra, cotton, and cacao, the largest genera in terms of number of species include Hibiscus, Sterculia, Dombeya, Pavonia and Sida. The circumscription of the Malvaceae is controversial, the traditional Malvaceae sensu stricto comprise a very homogeneous and cladistically monophyletic group. s. are not monophyletic groups. Thus, the Malvaceae can be expanded to all of these families so as to compose a monophyletic group. Adopting this circumscription, the Malvaceae incorporate a larger number of genera. This article is based on the circumscription, as presented by the Angiosperm Phylogeny Website. The Malvaceae s. l. comprise nine subfamilies, a tentative cladogram of the family is shown below. The diamond denotes a poorly supported branching, if looking for information about the traditional Malvaceae s. s. we recommend referring to Malvoideae, the subfamily that approximately corresponds to that group. The English common name comes from Latin malva. Malva itself was derived from the word for the plant in ancient Mediterranean languages. Cognates of the word include Ancient Greek μαλάχη or μολόχη, Modern Greek μολόχα, modern Arabic, ملوخية and modern Hebrew, most species are herbs or shrubs, but some are trees and lianas. Leaves are generally alternate, often lobed or compound and palmately veined. The margin may be entire, but when dentate, a vein ends at the tip of each tooth, the stems contain mucous canals and often also mucous cavities. Hairs are common, and are most typically stellate, the flowers are commonly borne in definite or indefinite axillary inflorescences, which are often reduced to a single flower, but may also be cauliflorous, oppositifolious, or terminal. They can be unisexual or bisexual, and are actinomorphic, often associated with conspicuous bracts. They generally have five sepals, most frequently basally connate. The stamens are five to numerous, and connate at least at their bases, the pistils are composed of two to many connate carpels. The ovary is superior, with axial placentation, with capitate or lobed stigma, the flowers have nectaries made of many tightly packed glandular hairs, usually positioned on the sepals
8.
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
9.
Deciduous
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In a more general sense, deciduous means the dropping of a part that is no longer needed or falling away after its purpose is finished. In plants it is the result of natural processes, in botany and horticulture, deciduous plants, including trees, shrubs and herbaceous perennials, are those that lose all of their leaves for part of the year. In some cases leaf loss coincides with winter—namely in temperate or polar climates, in other parts of the world, including tropical, subtropical, and arid regions, plants lose their leaves during the dry season or other seasons, depending on variations in rainfall. The converse of deciduous is coniferous, where foliage is shed on a different schedule from deciduous trees, plants that are intermediate may be called semi-deciduous, they lose old foliage as new growth begins. Other plants are semi-evergreen and lose their leaves before the growing season. Many deciduous plants flower during the period when they are leafless, the absence of leaves improves wind transmission of pollen for wind-pollinated plants and increases the visibility of the flowers to insects in insect-pollinated plants. This strategy is not without risks, as the flowers can be damaged by frost or, in dry season regions, leaf drop or abscission involves complex physiological signals and changes within plants. The process of photosynthesis steadily degrades the supply of chlorophylls in foliage, the brightest leaf colors are produced when days grow short and nights are cool, but remain above freezing. These other pigments include carotenoids that are yellow, brown, anthocyanin pigments produce red and purple colors, though they are not always present in the leaves. Rather, they are produced in the foliage in late summer, parts of the world that have showy displays of bright autumn colors are limited to locations where days become short and nights are cool. In other parts of the world, the leaves of deciduous trees simply fall off without turning the bright colors produced from the accumulation of anthocyanin pigments, the beginnings of leaf drop starts when an abscission layer is formed between the leaf petiole and the stem. This layer is formed in the spring during active new growth of the leaf, the cells are sensitive to a plant hormone called auxin that is produced by the leaf and other parts of the plant. The elongation of cells break the connection between the different cell layers, allowing the leaf to break away from the plant. It also forms a layer that seals the break, so the plant does not lose sap, in the spring, these proteins are used as a nitrogen source during the growth of new leaves or flowers. Plants with deciduous foliage have advantages and disadvantages compared to plants with evergreen foliage, evergreens suffer greater water loss during the winter and they also can experience greater predation pressure, especially when small. Losing leaves in winter may reduce damage from insects, repairing leaves, removing leaves also reduces cavitation which can damage xylem vessels in plants. This then allows deciduous plants to have xylem vessels with larger diameters, the deciduous characteristic has developed repeatedly among woody plants. Trees include maple, many oaks and nothofagus, elm, aspen, Deciduous shrubs include honeysuckle, viburnum, and many others
10.
Hybrid (biology)
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In biology, a hybrid, also known as a cross breed, is the result of combining, through sexual reproduction, the qualities of two animals or plants of different breeds, varieties, species or genera. Hybrids are not always intermediate between their parents, but can show heterosis or hybrid vigour, often growing larger or taller than either parent, some act before fertilization, others after it. A few animal species and many plant species, however, are the result of hybrid speciation, doubling the number of chromosomes to create polyploids is important in hybrid speciation, because homoploid hybrids are rarely fertile, the polyploid hybrids are allopolyploids. Human impact on the environment has greatly increased the mixing of species, with introduced species worldwide, the genetic mixing may threaten many species with extinction, while genetic erosion in crop plants may be damaging the gene pools of many species for future breeding. Many commercially useful fruits, flowers, garden herbs and trees have been produced by hybridization, one flower, Oenothera lamarckiana, was central to early genetics research into polyploidy. The term hybrid is derived from Latin hybrida, used for such as of a tame sow and a wild boar, or the child of a freeman. The term came into use in English in the 19th century. Conspicuous hybrids are named with portmanteau words, starting in the 1920s with the breeding of tiger-lion hybrids. The cross between two different homozygous lines produces an F1 hybrid that is heterozygous, having two alleles, one contributed by each parent and typically one is dominant and the other recessive. Typically, the F1 generation is also phenotypically homogeneous, producing offspring that are all similar to each other, double cross hybrids result from the cross between two different F1 hybrids. Three-way cross hybrids result from the cross between an F1 hybrid and an inbred line, triple cross hybrids result from the crossing of two different three-way cross hybrids. Top cross hybrids result from the crossing of a top quality or pure-bred male, population hybrids result from the crossing of plants or animals in a population with those of another population. These include interspecific hybrids or crosses between different breeds. e, from the point of view of genetics, different kinds of hybrid can be distinguished as follows, A genetic hybrid carries two different alleles of the same gene. A structural hybrid results from the fusion of gametes that have differing structure in at least one chromosome, a numerical hybrid results from the fusion of gametes having different haploid numbers of chromosomes. A permanent hybrid results when only the heterozygous genotype occurs, as in Oenothera lamarckiana, from the point of view of taxonomy, hybrids differ according to their parentage, Hybrids between different subspecies are called intra-specific hybrids. Offspring resulting from interspecies mating, are called interspecific hybrids, these result in hybrid speciation. Intergeneric hybrids result from matings between different genera, such as sheep and goats. Interfamilial hybrids such as chickens and guineafowl or pheasants are reliably described but extremely rare
11.
Hermaphrodite
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In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes. Many taxonomic groups of animals do not have separate sexes, in these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the female or male. For example, the majority of tunicates, pulmonate snails, opisthobranch snails. Hermaphroditism is also found in fish species and to a lesser degree in other vertebrates. Historically, the term hermaphrodite has also used to describe ambiguous genitalia and gonadal mosaicism in individuals of gonochoristic species. A rough estimate of the number of animal species is 65,000. Since the estimated number of animal species is 8.6 million. Arthropods are the phylum with the largest number of species, most hermaphroditic species exhibit some degree of self-fertilization. The distribution of self-fertilization rates among animals is similar to that of plants, suggesting that similar processes are operating to direct the evolution of selfing in animals and plants. The term derives from the Latin, hermaphroditus, from Ancient Greek, ἑρμαφρόδιτος hermaphroditos, which derives from Hermaphroditus, the word hermaphrodite entered the English lexicon as early as the late fourteenth century. Sequential hermaphrodites occur in species in which the individual is born as one sex and this contrasts simultaneous hermaphrodites, in which an individual may possess fully functional male and female gonads. Sequential hermaphroditism is common in fish and some jellyfish, many gastropods, while some sequential hermaphrodites can change sex multiple times, most can only change sex once. Generally one anemone contains a harem, consisting of a female, a smaller reproductive male. If the female is removed, the male will change sex. It has been shown that fishing pressure can change when the switch from male to female occurs, the populations are generally changing sex at a smaller size, due to natural selection. Protogyny, Where the organism is born as a female, and then changes sex to a male. Example, wrasses also have an uncommon life history strategy, which is termed diandry. In these species, two male morphs exists, an initial phase male and a terminal phase male, initial phase males do not look like males and spawn in groups with other females. Terminal phase males are territorial and have a distinctively bright coloration, individuals are born as males or females, but if they are born males, they are not born as terminal phase males
12.
Plant reproductive morphology
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Plant reproductive morphology is the study of the physical form and structure of those parts of plants directly or indirectly concerned with sexual reproduction. Among all living organisms, flowers, which are the structures of angiosperms, are the most varied physically. Plants that are not flowering plants also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction, christian Konrad Sprengel studied the reproduction of flowering plants and for the first time it was understood that the pollination process involved both biotic and abiotic interactions. Charles Darwins theories of natural selection utilized this work to build his theory of evolution, Plants have complex lifecycles involving alternation of generations. One generation, the sporophyte, gives rise to the next generation asexually via spores, spores may be identical isospores or come in different sizes, but strictly speaking, spores and sporophytes are neither male nor female because they do not produce gametes. The alternate generation, the gametophyte, produces gametes, eggs and/or sperm, a gametophyte can be be monoicous, producing both eggs and sperm or dioicous, either female or male. In the bryophytes, the gametophyte is the dominant generation. In ferns and seed plants the sporophyte is the dominant generation, the obvious visible plant, whether a small herb or a large tree, is the sporophyte, and the gametophyte is very small. In seed plants, each female gametophyte, and the spore that gives rise to it, is hidden within the sporophyte and is dependent on it for nutrition. Each male gametophyte consists of from two to four cells enclosed within the protective wall of a pollen grain. The sporophyte of a plant is often described using sexual terms based on the sexuality of the gametophyte it gives rise to. For example, a sporophyte that produces spores that give rise only to male gametophytes may be described as male, even though the sporophyte itself is asexual, producing only spores. Similarly, flowers produced by the sporophyte may be described as unisexual or bisexual, the flower is the characteristic structure concerned with sexual reproduction in flowering plants. Flowers vary enormously in their construction, a complete flower, like that of Ranunculus glaberrimus shown in the figure, has a calyx of outer sepals and a corolla of inner petals. The sepals and petals form the perianth. Next inwards there are numerous stamens, which produce pollen grains, stamens may be called the male parts of a flower and collectively form the androecium. Finally in the middle there are carpels, which at maturity one or more ovules. Carpels may be called the parts of a flower and collectively form the gynoecium
