1.
Acer pseudoplatanus
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Acer pseudoplatanus, known as the sycamore in the United Kingdom and the sycamore maple in the United States, is a flowering plant species in the soapberry and lychee family Sapindaceae. It is a deciduous, broad-leaved tree, tolerant of wind. It is native to Central Europe and Western Asia, from France eastwards to Ukraine, northern Turkey, the sycamore can grow to a height of about 35 m and the branches form a broad, rounded crown. The bark is grey, smooth when young and later flaking in irregular patches, the leaves grow on long leafstalks and are large and palmate, with 5 large radiating lobes. The flowers are greenish-yellow and hang in dangling flowerheads called panicles and they produce copious amounts of pollen and nectar that are attractive to insects. The winged seeds or samaras are borne in pairs and twirl to the ground when ripe and they germinate freely in the following spring. In its native range, the sycamore is associated with a range of invertebrates and fungi. The rising sap in spring has been used to extract sugar and make alcoholic and non-alcoholic drinks, Acer pseudoplatanus was first described by the Swedish naturalist Carl Linnaeus in his Species Plantarum in 1753. It is the species in the maple genus Acer. These are all now considered to be synonyms of Acer pseudoplatanus L, the specific name pseudoplatanus refers to the superficial similarity of the leaves and bark of the sycamore to those of plane trees in the genus Platanus, the prefix pseudo- meaning false. However, the two genera are in different families that are distantly related. Acer and Platanus differ in the position in which leaves are attached to the stem and in their fruit, the common name sycamore originally applied to the fig species Ficus sycomorus, the sycamore or sycomore referred to in the Bible, that is native to southwest Asia. Other common names for the tree include false plane-tree, great maple, Scottish maple, mount maple, mock-plane, the sycamore is a large, broadleaved deciduous tree that reaches 20–35 m tall at maturity, the branches forming a broad, domed crown. The bark of trees is smooth and grey but becomes rougher with age and breaks up into scales. The buds are produced in pairs, ovoid and pointed, with the bud scales green, edged in dark brown. When the leaves are shed they leave horseshoe shaped marks called leaf scars on the stem, the leaves are opposite, large,10 to 25 cm long and broad, palmate with 5 pointed lobes that are coarsely toothed or serrated. They have a texture with thick veins protruding on the underside. They are dark green in colour with a paler underside, some cultivars have purple-tinged or yellowish leaves
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.
Eudicots
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The eudicots, Eudicotidae or eudicotyledons are a monophyletic clade of flowering plants that had been called tricolpates or non-magnoliid dicots by previous authors. The close relationships among flowering plants with tricolpate pollen grains was initially seen in studies of shared derived characters. These plants have a trait in their pollen grains of exhibiting three colpi or grooves paralleling the polar axis. Later molecular evidence confirmed the basis for the evolutionary relationships among flowering plants with tricolpate pollen grains. The term means true dicotyledons, as it contains the majority of plants that have been considered dicots and have characteristics of the dicots, the term eudicots has subsequently been widely adopted in botany to refer to one of the two largest clades of angiosperms, monocots being the other. The remaining angiosperms are sometimes referred to as basal angiosperms or paleodicots, the other name for the eudicots is tricolpates, a name which refers to the grooved structure of the pollen. Members of the group have tricolpate pollen, or forms derived from it and these pollens have three or more pores set in furrows called colpi. In contrast, most of the seed plants produce monosulcate pollen. The name tricolpates is preferred by some botanists to avoid confusion with the dicots, numerous familiar plants are eudicots, including many common food plants, trees, and ornamentals. Most leafy trees of midlatitudes also belong to eudicots, with exceptions being magnolias and tulip trees which belong to magnoliids, and Ginkgo biloba. The name eudicots is used in the APG system, of 1998 and it is applied to a clade, a monophyletic group, which includes most of the dicots. The eudicots can be divided into two groups, the basal eudicots and the core eudicots, basal eudicot is an informal name for a paraphyletic group. The core eudicots are a monophyletic group, a 2010 study suggested the core eudicots can be divided into two clades, Gunnerales and a clade called Pentapetalae, comprising all the remaining core eudicots
6.
Rosids
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The rosids are members of a large clade of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms. The clade is divided into 16 to 20 orders, depending upon circumscription and classification and these orders, in turn, together comprise about 140 families. Fossil rosids are known from the Cretaceous period, molecular clock estimates indicate that the rosids originated in the Aptian or Albian stages of the Cretaceous, between 125 and 99.6 million years ago. The name is based upon the name Rosidae, which had usually been understood to be a subclass, in 1967, Armen Takhtajan showed that the correct basis for the name Rosidae is a description of a group of plants published in 1830 by Friedrich Gottlieb Bartling. The clade was later renamed Rosidae and has been variously delimited by different authors, the name rosids is informal and not assumed to have any particular taxonomic rank like the names authorized by the ICBN. The rosids are monophyletic based upon evidence found by molecular phylogenetic analysis, three different definitions of the rosids were used. Some authors included the orders Saxifragales and Vitales in the rosids, others excluded both of these orders. The circumscription used in this article is that of the APG IV classification, which includes Vitales, the rosids and Saxifragales form the superrosids clade. This is one of three groups compose the Pentapetalae, the others being Dilleniales and the superasterids. The rosids consist of two groups, the order Vitales and the eurosids, the eurosids, in turn, are divided into two groups, fabids and malvids. The rosids consist of 17 orders, in addition to Vitales, there are 8 orders in fabids and 8 orders in malvids. Some of the orders have only recently been recognized and these are Vitales, Zygophyllales, Crossosomatales, Picramniales, and Huerteales. The phylogeny of Rosids shown below is adapted from the Angiosperm Phylogeny Group website, the nitrogen-fixing clade contains a high number of actinorhizal plants. Not all plants in this clade are actinorhizal, however, media related to Rosids at Wikimedia Commons
7.
Sapindaceae
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The Sapindaceae are a family of flowering plants in the order Sapindales known as the soapberry family. It contains 138 genera and 1858 accepted species, including maple, ackee, horse chestnut, the Sapindaceae occur in temperate to tropical regions, many in laurel forest habitat, throughout the world. Many are laticiferous, i. e. they contain latex, a milky sap, the largest genera are Serjania, Paullinia, Acer and Allophylus. The largely temperate genera formerly separated in the families Aceraceae and Hippocastanaceae were included within a broadly circumscribed Sapindaceae by the APG. Recent research has confirmed the inclusion of genera in Sapindaceae. Plants of this family have a variety of habits, from trees to herbaceous plants or lianas and their leaves usually spirally alternate, sometimes opposite. They are most often pinnately compound, sometimes palmately compound as in Aesculus, the petiole has a swollen base and lacks stipules. Some genera and species have laurel forest foliage due to convergent evolution, flowers are small and unisexual, or functionally unisexual, though plants may be either dioecious or monoecious. They are usually grouped in cymes grouped in panicles and they most often have four or five petals and sepals. The stamens range from four to ten, usually on a disc between the petals and stamen, their filaments are often hairy. The most frequent number is eight, in two rings of four, the gynoecium contains two or three carpels, sometimes up to six. There is usually only one style with a lobed stigma, most often pollinated by birds or insects, with a few species pollinated by wind. The fruits are fleshy or dry and they may be nuts, berries, drupes, schizocarps, capsules, or samaras. The embryos are bent or coiled, without endosperm in the seed, Sapindaceae are related to Rutaceae, and both are usually placed in an order Sapindales or Rutales, depending on whether they are kept separate and which name is used for the order. The most basal member appears to be Xanthoceras, some authors maintain some or all of Hippocastanaceae and Aceraceae, although this may result in paraphyly. The former Ptaeroxylaceae, now placed in Rutaceae, were placed in Sapindaceae. The family is divided into 4 subfamilies, Sapindaceae includes many species of economically valuable tropical fruit, including the lychee, longan, pitomba, guinip/mamoncillo, korlan, rambutan, pulasan and ackee. Other products include guarana, soapberries and maple syrup, some species of Maple and Buckeye are valued for their wood, while several other genera, such as Koelreuteria, Cardiospermum and Ungnadia, are popular ornamentals
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.
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
10.
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
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.
Acer rubrum
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Acer rubrum is one of the most common and widespread deciduous trees of eastern and central North America. The U. S. Forest service recognizes it as the most abundant native tree in eastern North America. The red maple ranges from southeastern Manitoba around the Lake of the Woods on the border with Ontario and Minnesota, east to Newfoundland, south to Florida, many of its features, especially its leaves, are quite variable in form. At maturity it often attains a height of around 15 m and its flowers, petioles, twigs and seeds are all red to varying degrees. Among these features, however, it is best known for its brilliant deep scarlet foliage in autumn, over most of its range, red maple is adaptable to a very wide range of site conditions, perhaps more so than any other tree in eastern North America. It can be found growing in swamps, on dry soils. It grows well from sea level to about 900 m, due to its attractive fall foliage and pleasing form, it is often used as a shade tree for landscapes. It is used commercially on a scale for maple syrup production as well as for its medium to high quality lumber. It is also the State Tree of Rhode Island, the red maple can be considered weedy or invasive. It is taking over forests in the eastern US, replacing traditional mainstays like oaks, though A. rubrum is usually easy to identify, it is highly changeable in morphological characteristics. It is a medium to large sized tree, reaching heights of 18 to 27 metres, the leaves are usually 9 to 11 centimetres long on a full grown tree. The trunk diameter can range from 46 to 76 cm, depending on the growing conditions and its spread is about 12 m. A 10-year-old sapling will stand about 6 m tall, in forests, the bark will remain free of branches until some distance up the tree. Individuals grown in the open are shorter and thicker with a rounded crown. Generally speaking, however, the crown is irregularly ovoid with ascending whip-like curved shoots, the bark is a pale grey and smooth when the individual is young. As the tree grows the bark becomes darker and cracks into slightly raised long plates, the largest known living red maple is located near Armada, Michigan, at a height of 38.1 m and a bole circumference, at breast height, of 4.95 m. The leaves of the red maple offer the easiest way to distinguish it from its relatives, as with nearly all North American maple trees, they are deciduous and arranged oppositely on the twig. They are typically 5–10 cm long and wide with 3-5 palmate lobes with a serrated margin, the sinuses are typically narrow, but the leaves can exhibit considerable variation
13.
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
14.
Dioecy
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Dioecy is a characteristic of a species, meaning that it has distinct male and female individual organisms or colonies, meaning that a colony contains only either male or female individuals. Dioecy is one method that excludes self-fertilization and promotes allogamy, flowering plants have several other methods of excluding self-fertilization, called Self-incompatibility. In zoology, dioecious species may be opposed to hermaphroditic species, meaning that an individual is of one sex. Dioecy may also describe colonies, such as the colonies of Siphonophorae, Dioecious colonies contain members of only one sex, whereas monoecious colonies contain members of both sexes. Dioecious species have the male and female structures on separate plants. The meaning of male and female in the context of plants is different from that used in animal groups and this issue is discussed below in the Alternation of generations section. About 6 percent of species are entirely dioecious and about 7% of angiosperm genera contain some dioecious species. Examples of dioecious plant species include ginkgos, willows, cannabis, more examples of dioecious plants can be found in the Wikipedia category, Dioecious plants. Dioecy occurs in a variety of plant families. However it is common in woody plants and heterotrophic species. There are several alternatives to dioecy for sexual reproductive structure organization in plants including bisexual flowers and these are described at Plant reproductive morphology. Land plants have alternation of generations, for which the sporophyte produces spores rather than gametes. Strictly speaking, the sporophytes of plants do not have either male or female reproductive organs. The gametophytes of flowering plants are of a sex, the male gametophytes are contained within the pollen. The sporophyte generation is called dioecious when each sporophyte has only one kind of spore-producing organ whose spores ultimately give rise to all male gametes or all female gametes. Slightly different terms, dioicous and monoicous, may be used for the gametophyte generation, the definition avoids reference to male and female reproductive structures, which are rare in fungi. An individual of a fungal species not only requires a partner for mating. A monoecious fungal species can perform roles, but may not be self-compatible
15.
Acer saccharum
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Sugar maple is best known for its bright fall foliage and for being the primary source of maple syrup. Acer saccharum is a tree normally reaching heights of 25–35 m. A 10-year-old tree is typically about 5 m tall, when healthy, the sugar maple can live for over 400 years. The leaves are deciduous, up to 20 cm long and equally wide, the basal lobes are relatively small, while the upper lobes are larger and deeply notched. In contrast with the angular notching of the maple, however. The fall color is often spectacular, ranging from yellow through orange to fluorescent red-orange. Sugar maples also have a tendency to color unevenly in fall, in some trees, all colors above can be seen at the same time. They also share a tendency with red maples for certain parts of a tree to change color weeks ahead of or behind the remainder of the tree. The leaf buds are pointy and brown-colored, the recent years growth twigs are green, and turn dark brown. The flowers are in panicles of five to 10 together, yellow-green and without petals, the sugar maple will generally begin flowering when it is between 10 and 15 years old. The fruit is a pair of samaras, the seeds are globose, 7–10 mm in diameter, the wing 2–3 cm long. The seeds fall from the tree in autumn, where they must be exposed to 90 days of temperatures below −18 °C to break their coating down. Germination of A. saccharum is slow, not taking place until the spring when the soil has warmed. It is closely related to the maple, which is sometimes included in this species. The western American bigtooth maple is also treated as a variety or subspecies of sugar maple by some botanists, the sugar maple is also often confused with the Norway maple, though they are not closely related within the genus. The sugar maple is most easily identified by clear sap in the petiole, brown, sharp-tipped buds. Also, the lobes of the sugar maple have a more triangular shape. The sugar maple is an important species to the ecology of many forests in the northern United States
16.
Tree
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In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a group but include a variety of plant species that have independently evolved a woody trunk. In looser senses, the palms, the tree ferns, bananas. Trees tend to be long-lived, some reaching several thousand years old, the tallest known tree, a coast redwood named Hyperion, stands 115.6 m high. Trees have been in existence for 370 million years and it is estimated that there are just over 3 trillion mature trees in the world. A tree typically has many secondary branches supported clear of the ground by the trunk and this trunk typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier, below the ground, the roots branch and spread out widely, they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, the divide into smaller branches and shoots. The shoots typically bear leaves, which light energy and convert it into sugars by photosynthesis, providing the food for the trees growth. Flowers and fruit may also be present, but some trees, such as conifers, instead have pollen cones and seed cones, others, such as tree ferns, trees play a significant role in reducing erosion and moderating the climate. They remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues, trees and forests provide a habitat for many species of animals and plants. Tropical rainforests are one of the most biodiverse habitats in the world, trees provide shade and shelter, timber for construction, fuel for cooking and heating, and fruit for food as well as having many other uses. In parts of the world, forests are shrinking as trees are cleared to increase the amount of available for agriculture. Because of their longevity and usefulness, trees have always revered, with sacred groves in various cultures. Although tree is a term of common parlance, there is no universally recognised precise definition of what a tree is, either botanically or in common language. In its broadest sense, a tree is any plant with the form of an elongated stem, or trunk. Trees are also defined by height, with smaller plants from 0.5 to 10 m being called shrubs
17.
Shrub
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A shrub or bush is a small to medium-sized woody plant. It is distinguished from a tree by its multiple stems and shorter height, plants of many species may grow either into shrubs or trees, depending on their growing conditions. Small, low shrubs, generally less than 2 m tall, such as lavender, periwinkle, an area of cultivated shrubs in a park or a garden is known as a shrubbery. When clipped as topiary, suitable species or varieties of shrubs develop dense foliage, many shrubs respond well to renewal pruning, in which hard cutting back to a stool results in long new stems known as canes. Other shrubs respond better to selective pruning to reveal their structure, shrubs in common garden practice are generally considered broad-leaved plants, though some smaller conifers such as mountain pine and common juniper are also shrubby in structure. Species that grow into a shrubby habit may be deciduous or evergreen
18.
Trunk (botany)
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The trunk is the most important part of the tree for timber production. Trunks occur both in true woody plants as well as plants such as palms and other monocots. In all plants, trunks thicken over time due to formation of secondary growth, trunks can be vulnerable to damage, including sunburn. Trunks which are cut down in logging are generally called logs, basal area Tree measurement Tree volume measurement Diameter at breast height Inside a tree trunk from the University of the Western Cape
19.
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
20.
Autumn leaf color
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The phenomenon is commonly called autumn colours or autumn foliage in British English and fall colors, fall foliage, or simply foliage in American English. In some areas of Canada and the United States, leaf peeping tourism is a contribution to economic activity. A green leaf is green because of the presence of a pigment known as chlorophyll, thus, the leaves of summer are characteristically green. Chlorophyll has a function, it captures solar rays and uses the resulting energy in the manufacture of the plants food — simple sugars which are produced from water. These sugars are the basis of the plants nourishment — the sole source of the carbohydrates needed for growth, in their food-manufacturing process, the chlorophylls breaks down, thus are being continually used up. During the growing season, however, the plant replenishes the chlorophyll so that the supply remains high, as this cork layer develops, water and mineral intake into the leaf is reduced, slowly at first, and then more rapidly. During this time, the chlorophyll begins to decrease, often, the veins are still green after the tissues between them have almost completely changed color. Much chlorophyll is in photosystem II, the most abundant membrane protein on earth, LHC II captures light in photosynthesis. It is located in the membrane of the chloroplast and it is composed of an apoprotein along with several ligands. In the fall, this complex is broken down, chlorophyll degradation is thought to occur first. This is believed to destabilize the complex, at which point breakdown of the apoprotein occurs, an important enzyme in the breakdown of the apoprotein is FtsH6, which belongs to the FtsH family of proteases. Chlorophylls degrade into colorless tetrapyrroles known as nonfluorescent chlorophyll catabolites, as the chlorophylls degrade, the hidden pigments of yellow xanthophylls and orange beta-carotene are revealed. These pigments are present throughout the year, but the red pigments, carotenoids are present in leaves the whole year round, but their orange-yellow colors are usually masked by green chlorophyll. As autumn approaches, certain influences both inside and outside the plant cause the chlorophylls to be replaced at a slower rate than they are being used up, during this period, with the total supply of chlorophylls gradually dwindling, the masking effect slowly fades away. Then other pigments that have been present in the cells all during the leafs life begin to show through and these are carotenoids and they provide colorations of yellow, brown, orange, and the many hues in between. The carotenoids occur, along with the pigments, in tiny structures called plastids. Sometimes, they are in abundance in the leaf that they give a plant a yellow-green color. Usually, however, they become prominent for the first time in autumn, carotenoids are common in many living things, giving characteristic color to carrots, corn, canaries, and daffodils, as well as egg yolks, rutabagas, buttercups, and bananas
21.
Mediterranean region
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As a rule of thumb, the Mediterranean Basin is the Old World region where olive trees grow. The Mediterranean basin covers portions of three continents Africa, Asia, and Europe and it has a varied and contrasting topography. Contrary to the sandy beach images portrayed in most tourist brochures. Mountains can be seen from almost anywhere, the Mediterranean Basin extends into Western Asia, covering the western and southern portions of the peninsula of Turkey, excluding the temperate-climate mountains of central Turkey. It includes the Mediterranean climate Levant at the end of the Mediterranean, bounded on the east and south by the Syrian. The northern portion of the Maghreb region of northwestern Africa has a Mediterranean climate, separated from the Sahara Desert, Europe lies to the north, and three large Southern European peninsulas, the Iberian Peninsula, Italian Peninsula, and the Balkan Peninsula, extend into the Mediterranean-climate zone. The Mediterranean Basin was shaped by the ancient collision of the northward-moving African-Arabian continent with the stable Eurasian continent, as Africa-Arabia moved north, it closed the former Tethys Sea, which formerly separated Eurasia from the ancient super continent of Gondwana, of which Africa was part. At about the time,170 mya in the Jurassic period. The collision pushed up a vast system of mountains, extending from the Pyrenees in Spain to the Zagros Mountains in Iran and this episode of mountain building, known as the Alpine orogeny, occurred mostly during the Oligocene and Miocene epochs. The Neotethys became larger during these collisions and associated folding and subduction, about 6 mya during the late Miocene, the Mediterranean was closed at its western end by drifting Africa, which caused the entire sea to evaporate. There followed several episodes of sea drawdown and re-flooding known as the Messinian Salinity Crisis, recent studies, however, show that repeated desiccation and re-flooding is unlikely from a geodynamic point of view. The end of the Miocene also marked a change in the Mediterranean Basins climate, fossil evidence shows that the Mediterranean Basin had a relatively humid subtropical climate with summer rainfall during the Miocene, which supported laurel forests. The shift to a Mediterranean climate occurred within the last 3. 2–2.8 million years, during the Pliocene epoch, much of these forests and shrublands have been altered beyond recognition by thousands of years of human habitation. There are now very few relatively intact natural areas in what was once a wooded region. The Mediterranean Region was first proposed by German botanist August Grisebach in the late 19th century, drosophyllaceae, recently segregated from Droseraceae, is the only plant family endemic to the region. Among the endemic plant genera are, The genera Aubrieta, Sesamoides, Cynara, Dracunculus, moreover, many plant taxa are shared with one of the four neighboring floristic regions only. The Mediterranean Basin is the largest of the worlds five Mediterranean forests, woodlands and it is home to a number of plant communities, which vary with rainfall, elevation, latitude, and soils. Scrublands occur in the driest areas, especially areas near the seacoast where wind, low, soft-leaved scrublands around the Mediterranean are known as garrigar in Catalan, garrigue in French, phrygana in Greek, tomillares in Spanish, and batha in Hebrew
22.
Evergreen
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In botany, an evergreen is a plant that has leaves throughout the year, always green. This contrasts with deciduous plants, which lose their foliage during the winter or dry season. There are many different kinds of plants, both trees and shrubs. Deciduous trees shed their leaves, usually as an adaptation to a cold or dry/wet season, evergreen trees do lose leaves, but each tree loses its leaves gradually and not all at once. Most warm temperate climate plants are also evergreen, in cool temperate climates, fewer plants are evergreen, with a predominance of conifers, as few evergreen broadleaf plants can tolerate severe cold below about −30 °C. In areas where there is a reason for being deciduous, being evergreen is usually an adaptation to low nutrient levels, deciduous trees lose nutrients whenever they lose their leaves. In warmer areas, species such as pines and cypresses grow on poor soils. In Rhododendron, a genus with many broadleaf evergreens, several species grow in forests but are usually found on highly acidic soil where the nutrients are less available to plants. In taiga or boreal forests, it is too cold for the matter in the soil to decay rapidly, so the nutrients in the soil are less easily available to plants. These conditions favour the growth of more evergreens and make it difficult for deciduous plants to persist. In addition, the shelter provided by existing evergreen plants can make it easier for younger evergreen plants to survive cold and/or drought
23.
Shade tolerance
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In ecology, shade tolerance refers to a plants ability to tolerate low light levels. The term is used in horticulture and landscaping, although in this context its use is sometimes sloppy. Shade tolerance is a term, a complex, multi-faceted property of plants. Different plant species exhibit different adaptations to shade, in fact, a particular plant can exhibit varying degrees of shade tolerance, or even of requirement for light, depending on its history or stage of development. Except for some plants, all plants need sunlight to survive. However, in general, more sunlight does not always make it easier for plants to survive, in direct sunlight, plants face desiccation and exposure to UV rays, and must expend energy producing pigments to block UV light, and waxy coatings to prevent water loss. Plants adapted to shade have the ability to utilise far-red light more effectively than plants adapted to full sunlight, most red light gets absorbed by the shade-intolerant canopy plants, but more of the far-red light penetrates the canopy, reaching the understory. The shade-tolerant plants found here are capable of using light at such wavelengths. On the other hand, when light is available, less energy is available to the plant. Whereas in sunny and dry environments water can be a factor in growth and survival, in shade. The situation with respect to nutrients is often different in shade, most shade is due to the presence of a canopy of other plants, and this is usually associated with a completely different environment—richer in soil nutrients—than sunny areas. Shade-tolerant plants are adapted to be efficient energy-users. In simple terms, shade-tolerant plants grow broader, thinner leaves to more sunlight relative to the cost of producing the leaf. Shade-tolerant plants are usually adapted to make more use of soil nutrients than shade-intolerant plants. A distinction may be made between shade-tolerant plants and shade-loving or sciophilous plants, sciophilous plants are dependent on a degree of shading that would eventually kill most other plants, or significantly stunt their growth. Plants applied multilevel adaptations to the light environment from the systemic level to the molecular level. Various types of movement for adaptation to changing light environment have been identified, developmental. Some plants utilize blue-light absorbing pigments as a sensor and pulvinar motor tissue to drive leaf movement and these adaptions are usually slow but relatively efficient
24.
Root
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In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. Roots can also be aerial or aerating, that is growing up above the ground or especially above water, furthermore, a stem normally occurring below ground is not exceptional either. Therefore, the root is best defined as the non-leaf, non-nodes bearing parts of the plants body, however, important internal structural differences between stems and roots exist. The fossil record of roots – or rather, infilled voids where roots rotted after death – spans back to the late Silurian and their identification is difficult, because casts and molds of roots are so similar in appearance to animal burrows. They can be discriminated using a range of features, the first root that comes from a plant is called the radicle. In response to the concentration of nutrients, roots also synthesise cytokinin, Roots often function in storage of food and nutrients. The roots of most vascular plant species enter into symbiosis with fungi to form mycorrhizae. In its simplest form, the root architecture refers to the spatial configuration of a plant’s root system. This system can be complex and is dependent upon multiple factors such as the species of the plant itself, the composition of the soil. The configuration of root systems serves to support the plant, compete with other plants. Roots grow to specific conditions, which, if changed, can impede a plants growth. For example, a system that has developed in dry soil may not be as efficient in flooded soil, yet plants are able to adapt to other changes in the environment. Root architecture plays the important role of providing a supply of nutrients and water as well as anchorage. The main terms used to classify the architecture of a system are, Branch magnitude. Root angle, the angle of a lateral root’s base around the parent root’s circumference, the angle of a lateral root from its parent root. Link radius, the diameter of a root, all components of the root architecture are regulated through a complex interaction between genetic responses and responses due to environmental stimuli. These developmental stimuli are categorised as intrinsic, the genetic and nutritional influences, or extrinsic, the main hormones and respective pathways responsible for root architecture development include, Auxin – Auxin promotes root initiation, root emergence and primary root elongation. Cytokinins – Cytokinins regulate root apical meristem size and promote lateral root elongation, gibberellins – Together with ethylene they promote crown primordia growth and elongation
25.
Acer cappadocicum
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Acer cappadocicum is a maple native to Asia, from central Turkey east along the Caucasus, the Himalaya, to southwestern China. It is a deciduous tree growing to 20-30 m tall with a broad. The leaves are opposite, palmately lobed with 5-7 lobes, 6-15 cm across, the leaf stems bleed a milky latex when broken. The flowers are in corymbs of 15-30 together, yellow-green with five petals 3-4 mm long, flowering occurs in early spring, the fruit is a double samara with two winged seeds, the seeds are disc-shaped, strongly flattened, 6-11 mm across and 2-3 mm thick. The wings are 2. 5-3 cm long, widely spread, the bark is greenish-grey, smooth in young trees, becoming shallowly grooved when mature. There are three varieties, sometimes treated as subspecies, Acer cappadocicum var. cappadocicum, the closely related Acer lobelii from southern Italy is also treated as a subspecies of A. cappadocicum by some authors. The eastern Asian species Acer amplum, Acer pictum, and Acer truncatum are also closely related. Cappadocian maple is grown as a tree in Europe. Many of the trees in cultivation show a tendency to produce numerous root sprouts. The hybrid maple Acer × zoeschense shares this character and probably has Acer cappadocicum as one of its parents, the following cultivars have gained the Royal Horticultural Societys Award of Garden Merit, - A. cappadocicum Aureum A. cappadocicum Rubrum
26.
Basal shoot
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Basal shoots, root sprouts, adventitious shoots, water sprouts and suckers are various types of shoots which grow from a bud at the base of a tree or shrub or from adventitious buds in its roots. A plant that produces suckers is referred to as surculose, root suckers may emerge some distance from the originating plant, are considered a form of vegetative dispersal, and may originate a habitat patch where that tree is the dominant species. Suckers also may arise from the roots of trees that have cut down. In botany, a sucker is a plant growing not from a seed and this is a phenomenon of natural asexual spread, also known in plants as vegetative reproduction. It is a plant propagation strategy and the complex of individuals formed by a plant and all its clones produced form a single genetic individual. The plant suckers are clones from the mother plant, the plant will have a genome identical to that from which it arose. Many species of plant reproduce through vegetative reproduction, such as the Canada thistle, cherry, Apple, Ligustrum, hazel, Tree of Heaven, the guava, a tropical tree, is also known to propagate through basal shoots. The basal shoot is a variety of dispersal vector that allows the plants to reach specific habitats that are favorable for their survival and they create a shaded area where new species will grow and gradually replace them in many cases. In trees, the roots normally grow outward to about three times the branch spread, only half of a trees root system occurs between the trunk and the circumference of its canopy. Roots on one side of a tree normally supply the foliage on that side of the tree. Thus when roots on one side of a tree are injured, for some trees however, such as the maple family, the effect of a root injury may show itself anywhere in the tree canopy. Stolons are stems which grow at the surface or just below ground and form adventitious roots at the nodes. Thus, not all horizontal stems are called stolons, plants with stolons are called stoloniferous. Rhizomes, in contrast, are root-like stems that may either grow horizontally at the surface or in other orientations underground. Suckers and basal shoots can be used to propagate woody plants, suckers can be dug or broken off with some of the roots attached. Stool beds involve cutting a young plant to near ground level and heaping soil over it so that basal shoots will form adventitious roots, the technique is used particularly for vegetative propagation of rootstocks for apple trees. Suckers on some plants are considered undesirable by horticulturists because the plants energy is diverted to the sucker rather than to crown growth. Horticulturists recommend removing suckers on trees and shrubs by tearing them away as close to the base as possible, the buds that give rise to suckers are more completely destroyed through tearing than through cutting
27.
Clonal colony
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In plants, an individual in such a population is referred to as a ramet. In fungi, individuals typically refers to the fruiting bodies or mushrooms that develop from a common mycelium which. Clonal colonies are common in many plant species, although many plants reproduce sexually through the production of seed, reproduction occurs by underground stolons or rhizomes in some plants. Above ground, these appear to be distinct individuals. However, it is not always easy to recognize a clonal colony especially if it spreads underground and is also sexually reproducing, with most woody plants, clonal colonies arise by wide-ranging roots that at intervals send up new shoots, termed suckers. Trees and shrubs with branches that touch the ground can form colonies via layering, e. g. willow, some vines naturally form adventitious roots on their stems that take root in the soil when the stems contact the ground, e. g. ivy and trumpet vine. With other vines, rooting of the stem nodes come into contact with soil may establish a clonal colony. Ferns and many flowering plants often form clonal colonies via horizontal underground stems termed rhizomes, e. g. ostrich fern Matteuccia struthiopteris. A number of flowering plants form clonal colonies via horizontal surface stems termed stolons, or runners, e. g. strawberry. Non-woody plants with underground storage organs such as bulbs and corms can also form colonies, a few plant species can form colonies via adventitious plantlets that form on leaves, e. g. Kalanchoe daigremontiana and Tolmiea menziesii. A few plant species can form colonies via asexual seeds, termed apomixis, a group of 47,000 Quaking Aspen trees in the Wasatch Mountains, Utah, United States, has been shown to be a single clone connected by the root system. It is sometimes considered the worlds largest organism by mass, covering 106 acres and it is possible that other unknown clonal colonies of trees rival or exceed its size. The only known plant of Kings Lomatia in Tasmania is a clonal colony estimated to be 43,600 years old. Another possible candidate for oldest organism on earth is a stand of the marine plant Posidonia oceanica in the Mediterranean Sea, when woody plants form clonal colonies, they often remain connected through the root system, sharing roots, water and mineral nutrients. A Field Guide to Eastern Forests, pp. 19–20
28.
Acer circinatum
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It belongs to the Palmatum group of maple trees native to East Asia with its closest relatives being the Acer japonicum and Acer pseudosieboldianum. It can be difficult to distinguish from species in cultivation. It is the member of the Palmatum group that resides outside of Asia. It most commonly grows as a shrub growing to around 5 to 8 metres tall. The shoots are slender and hairless and it typically grows in the under story below much taller forest trees, but can sometimes be found in open ground, and occurs at altitudes from sea level up to 1,500 metres. The leaves turn yellow to orange-red in fall. The flowers are small,6 to 9 millimetres in diameter, with a red calyx and five short greenish-yellow petals. The fruit is a samara, each seed 8 to 10 millimetres in diameter. Vine maple trees can bend over easily, sometimes, this can cause the top of the tree to grow into the ground and send out a new root system, creating a natural arch. This characteristic makes it the only capable of layering. It is occasionally cultivated outside its range as an ornamental tree, from Juneau, Alaska and Ottawa, Ontario to Huntsville, Alabama
29.
Leaf
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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
30.
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
31.
Acer griseum
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Acer griseum is a species of flowering plant in the family Sapindaceae, native to central China. Acer griseum is found in the Chinese provinces of Gansu, Henan, Hubei, Hunan, Shaanxi, Shanxi and Sichuan, at altitudes of 1, 500–2,000 m. It is a small to medium-sized deciduous tree, reaching 6–9 m tall and 5–6 m wide, the bark is smooth, shiny orange-red, peeling in thin, papery layers, it may become fissured in old trees. The shoots are densely downy at first, this wearing off by the second or third year and the bark exfoliating by the third or fourth year. The leaves are compound, with a 2–4 cm petiole with three leaflets, each 3-10 cm long and 2-6 cm broad, dark green above, bright glaucous blue-green beneath, with blunt teeth on the margins. The yellow flowers are androdioecious, produced in small pendent corymbs in spring, Acer griseum was introduced to cultivation in Europe in 1901 by Ernest Henry Wilson for the Veitch Nurseries, and to North America shortly after. It is one of many species of maples widely grown as ornamental plants in temperate regions and it is admired for its decorative exfoliating bark, translucent pieces of which often stay attached to the branches until worn away. It also has spectacular autumn foliage which can include red, orange, propagation of Acer griseum is somewhat difficult as seeds have the same parthenocarpic tendencies as those of Acer maximowiczianum
32.
Acer mandshuricum
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Acer mandshuricum, is a species of maple native to China, Korea and Russia. Acer mandshuricum is a deciduous tree that reaches a height of up to 30 meters tall but is usually smaller. It is a trifoliate maple related to other species as three-flower maple and paperbark maple but has smooth. It leafs out early in the spring and the green leaves are contrast with its red petioles throughout the growing season. The flowers are yellowish-green, produced in corymbs of three to five together, the hard, horizontally-spreading samaras are 3-3.5 cm long and 1 cm broad. The species was first introduced to cultivation in 1904, when trees were planted at the Royal Botanic Gardens, best growth occurs in full sun to partial shade and in acid to neutral soil that is moist but well-drained. In Canada, the Royal Botanical Gardens in Hamilton, Ontario have three Manchurian maples each about 10 m tall, media related to Acer mandshuricum at Wikimedia Commons Data related to Acer mandshuricum at Wikispecies
33.
Acer maximowiczianum
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Acer maximowiczianum, is a species of maple widely distributed in China and Japan. It is a deciduous tree that reaches a height of 15–20 m but is usually smaller. It is a maple, related to such other species as Threeflower Maple. The leaves have a 3–5 centimeters petiole and three leaflets, the leaflets are oblong, 5–15 centimeters long and 3–6 centimeters broad, with dense, soft pubescence and smooth margins. The hard, horizontally-spreading samaras are 3. 5–6 centimeters long and 1.2 centimeters broad, the Chinese populations are sometimes treated as a separate subspecies A. maximowiczianum subsp. Megalocarpum A. E. Murray, but this is not recognised as distinct by the Flora of China, many older texts refer to the species under its synonym A. nikoense Maxim. But as Maximowicz had also cited the name Negundo nikoense Miq. in synonymy, acerogenin M, a cyclic diarylheptanoid, can be found in A. nikoense. Nikko Maple was first introduced to cultivation in 1881, when seeds were imported by the Veitch Nurseries in England and it is rarely seen in cultivation outside of arboreta. The largest specimens in England are up to 17 meters tall and 70 centimeters trunk diameter, in the United States, a mature specimen may be seen at Arnold Arboretum in Boston, Massachusetts
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Acer triflorum
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Acer triflorum, the three-flowered maple, is a species of maple native to hills of northeastern China and Korea. It is a tree that reaches a height of about 25 metres but is usually smaller. It is a trifoliate maple related to other species as Manchurian Maple. It has yellowish-brown exfoliating bark that peels in woody scales rather than papery pieces like Acer griseum, the flowers are yellow, produced in small corymbs of three small flowers each, hence the name. The samaras are 3. 5–4.5 centimetres long and 1. 3–2 cm broad, hairy, even more than its relatives, three-flower maple has spectacular fall colour that may include brilliant orange, scarlet, purple and gold. It is one of the few trees to develop good fall colour in shade, the species was first introduced to cultivation in 1923. Although common in collections, it is rarely seen in cultivation outside of arboreta. It grows at a slow to moderate rate and prefers moist, well drained soil and it is relatively tolerant of drought and clay compared to its close relatives. It does not tolerate wet or over-compacted soil, propagation is similar to that required for Acer griseum and the number of viable seeds is likewise very small. In Great Britain, the largest specimens are up to 13 m tall and it has gained the Royal Horticultural Societys Award of Garden Merit. In the United States, mature specimens can be seen at Arnold Arboretum in Boston, Massachusetts
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Acer negundo
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Acer negundo is a species of maple native to North America. Box elder, boxelder maple, ash-leaved maple, and maple ash are its most common names in the United States, in Britain, indicative of its familiarity to many people over a large geographic range, A. negundo has numerous common names. The names box elder and boxelder maple are based upon the similarity of its wood to that of boxwood. This is the only North American maple with compound leaves, though several Asian species also have them. Other common names are based upon this maples similarity to ash, its environment, its sugary sap, a description of its leaves, its binomial name. These names include ash-, cut-, or three-leaf maple, ash maple, sugar ash, Negundo maple, in Canada it is commonly known as Manitoba maple and occasionally as elf maple. In Russia it is called American maple as well as ash-leaf maple, common names may also designate a particular subspecies. For example, a name for A. negundo subsp. Interius may be preceded by inland, a common name for A. negundo subsp. Californicum may be preceded by California or western, Acer negundo is a usually fast-growing and fairly short-lived tree that grows up to 10–25 meters tall, with a trunk diameter of 30–50 centimeters, rarely up to 1 meter diameter. It often has several trunks and can form impenetrable thickets, the shoots are green, often with a whitish to pink or violet waxy coating when young. Branches are smooth, somewhat brittle, and tend to retain a fresh green colour rather than forming a bark of dead, the bark on its trunks is pale gray or light brown, deeply cleft into broad ridges, and scaly. Unlike most other maples, Acer negundo has pinnately compound leaves that usually have three to seven leaflets, simple leaves are also occasionally present, technically, these are single-leaflet compound leaves. Although some other maples have trifoliate leaves, only A. negundo regularly displays more than three leaflets, the leaflets are about 5–10 centimeters long and 3–7 centimeters wide with slightly serrate margins. Leaves have a translucent light green color and turn yellow in the fall, the flowers are small and appear in early spring on drooping racemes 10–20 centimeters long. The fruits are paired samaras, each seed slender, 1–2 centimeters long, with a 2–3 centimeters incurved wing, seeds are usually both prolific and fertile. Unlike most other maples, A. negundo is fully dioecious, winter buds, Terminal buds acute, an eighth of an inch long. The inner scales enlarge when spring begins and often become an inch long before they fall
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Acer laevigatum
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Acer laevigatum, is an atypical species of maple native to southern China, northern India, northern Myanmar, Nepal, and northern Vietnam. It grows at altitudes of 1, 000-2,000 m. Acer laevigatum is a tree growing to a height of 10–15 m or more. The leaves are smooth, unlobed, leathery, olive-green, and about 6–15 cm long and 3–5 cm wide, the leaves are normally persistent, and only drop in winter in unusually severe frost. The samaras are 4–7 cm long and have a purplish tone, there are two varieties, which may not be fully distinct, Acer laevigatum var. laevigatum Most of the species range. Acer laevigatum var. salweenense J. M. Cowan ex W. P. Fang - Yunnan. This tree is rarely seen in maple collections as it is too tender for many locations, with successful cultivation north to Ireland in Europe. One in Cornwall is 17 m tall
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Acer carpinifolium
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Acer carpinifolium is a species of maple native to Japan, on the islands of Honshū, Kyūshū, and Shikoku, where it grows in woodlands and alongside streams in mountainous areas. It is a deciduous tree growing to 10–15 m tall, with smooth. The leaves are 7–15 cm long and 3–6 cm broad, simple, unlobed, and pinnately veined with 18–24 pairs of veins and a serrated margin. They resemble leaves of more than they do other maples, except for being arranged in opposite pairs. The flowers are 1 cm diameter, greenish yellow, produced in pendulous racemes 5–12 cm long in spring as the new leaves open, they are dioecious, the fruit is a samara of two seeds each with a 2–3 cm long wing. Both the scientific and common names derive from the resemblance of its leaves to those of the genus Carpinus. Hornbeam, for the genus Carpinus found in Europe and eastern North America Hornbeam Maple Large Format Diagnostic Photos, Morton Arboretum acc. 1-61-4
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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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Symmetry in biology
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Symmetry in biology is the balanced distribution of duplicate body parts or shapes within the body of an organism. In nature and biology, symmetry is always approximate, for example plant leaves, while considered symmetrical, symmetry creates a class of patterns in nature, where the near-repetition of the pattern element is by reflection or rotation. The body plans of most multicellular organisms exhibit some form of symmetry, whether radial, bilateral, a small minority, notably among the sponges, exhibit no symmetry. Radially symmetric organisms resemble a pie where several cutting planes produce roughly identical pieces, such an organism exhibits no left or right sides. They have a top and a surface only. Most radially symmetric animals are symmetrical about an axis extending from the center of the oral surface, radial symmetry is especially suitable for sessile animals such as the sea anemone, floating animals such as jellyfish, and slow moving organisms such as starfish. Animals in the phyla cnidaria and echinodermata are radially symmetric, although many sea anemones and some corals have bilateral symmetry defined by a single structure, many flowers are radially symmetric or actinomorphic. Roughly identical flower parts – petals, sepals, and stamens occur at intervals around the axis of the flower. Many viruses have radial symmetries, their coats being composed of a small number of protein molecules arranged in a regular pattern to form polyhedrons, spheres. Tetramerism is a variant of radial symmetry found in jellyfish, which have four canals in an otherwise radial body plan, pentamerism, another variant of radial symmetry, means the organism is in five parts around a central axis, 72° apart. Among animals, only the echinoderms such as sea stars, sea urchins, being bilaterian animals, however, they initially develop with mirror symmetry as larvae, then gain pentaradial symmetry later. Flowering plants show fivefold symmetry in many flowers and in various fruits and this is well seen in the arrangement of the five carpels in an apple cut transversely. Hexamerism is found in the corals and sea anemones which are divided into two based on their symmetry. The most common corals in the subclass Hexacorallia have a body plan, their polyps have sixfold internal symmetry. Octamerism is found in corals of the subclass Octocorallia and these have polyps with eight tentacles and octameric radial symmetry. The octopus, however, has symmetry, despite its eight arms. Spherical symmetry occurs in an if it is able to be cut into two identical halves through any cut that runs through the organisms center. Organisms which show approximate spherical symmetry include the green alga Volvox
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Raceme
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A raceme is an unbranched, indeterminate type of inflorescence bearing pedicellate flowers—flowers having short floral stalks called pedicels—along its axis. In botany, an axis means a shoot, in case one bearing the flowers. In indeterminate inflorescence-like racemes, the oldest flowers are borne towards the base and new flowers are produced as the shoot grows, a plant that flowers on a showy raceme may have this reflected in its scientific name, e. g. Cimicifuga racemosa. A compound raceme, also called a panicle, has a main axis. Examples of racemes occur on mustard and radish plants, a spike is an unbranched, indeterminate inflorescence, similar to a raceme, but bearing sessile flowers. Examples occur on Malabar nut and chaff flowers, a true spikelet comprises one or more florets enclosed by two glumes, with flowers and glumes arranged in two opposite rows along the spikelet. Examples occur on rice and wheat, both grasses, an ament or catkin is very similar to a spike or raceme, but with subtending bracts so conspicuous as to conceal the flowers until pollination, as in the pussy–willow, alder, birch. These are sometimes called amentaceous plants, a spadix is a form of spike in which the florets are densely crowded along a fleshy axis, and enclosed by one or more large, brightly–colored bracts called spathes. Usually the female flowers grow at the base, and male flowers grow above and they are a characteristic of the Araceae family, for example jack–in–the–pull it and wild calla. From classical Latin racemus, cluster of grapes
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Sepal
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A sepal is a part of the flower of angiosperms. Usually green, sepals typically function as protection for the flower in bud, the term sepalum was coined by Noël Martin Joseph de Necker in 1790, and derived from the Greek σκεπη, a covering. Collectively the sepals are called the calyx, the outermost whorl of parts that form a flower, the word calyx was adopted from the Latin calyx, not to be confused with calix, a cup or goblet. Calyx derived from the Greek κάλυξ, a bud, a calyx, a husk or wrapping, while derived from the Greek κυλιξ, a cup or goblet. After flowering, most plants have no use for the calyx which withers or becomes vestigial. Some plants retain a thorny calyx, either dried or live, examples include species of Acaena, some of the Solanaceae, and the water caltrop, Trapa natans. In some species the calyx not only persists after flowering, but instead of withering and this is an effective protection against some kinds of birds and insects, for example in Hibiscus trionum and the Cape gooseberry. Morphologically, both sepals and petals are modified leaves, the calyx and the corolla are the outer sterile whorls of the flower, which together form what is known as the perianth. The term tepal is usually applied when the parts of the perianth are difficult to distinguish, e. g. the petals and sepals share the same color, or the petals are absent and the sepals are colorful. When the undifferentiated tepals resemble petals, they are referred to as petaloid, as in petaloid monocots, since they include Liliales, an alternative name is lilioid monocots. Examples of plants in which the term tepal is appropriate include genera such as Aloe, in contrast, genera such as Rosa and Phaseolus have well-distinguished sepals and petals. The number of sepals in a flower is its merosity, flower merosity is indicative of a plants classification. The merosity of a flower is typically four or five. The merosity of a monocot or palaeodicot flower is three, or a multiple of three, the development and form of the sepals vary considerably among flowering plants. They may be free or fused together, often, the sepals are much reduced, appearing somewhat awn-like, or as scales, teeth, or ridges. Most often such structures protrude until the fruit is mature and falls off, examples of flowers with much reduced perianths are found among the grasses. In some flowers, the sepals are fused towards the base, in other flowers a hypanthium includes the bases of sepals, petals, and the attachment points of the 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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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
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Gynoecium
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Gynoecium is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of pistils in a flower and is surrounded by the pollen-producing reproductive organs. The term gynoecium is also used by botanists to refer to a cluster of archegonia and any associated modified leaves or stems present on a shoot in mosses. The corresponding terms for the parts of those plants are clusters of antheridia within the androecium. Flowers that bear a gynoecium but no stamens are called carpellate, flowers lacking a gynoecium are called staminate. The gynoecium is often referred to as female because it gives rise to female gametophytes, however, strictly speaking sporophytes do not have a sex, only gametophytes do. Gynoecium development and arrangement is important in research and identification of angiosperms. The gynoecium may consist of one or more separate pistils, a pistil typically consists of an expanded basal portion called the ovary, an elongated section called a style and an apical structure that receives pollen called a stigma. The ovary, is the basal portion which contains placentas. The placentas and/or ovule may be born on the gynoecial appendages or less frequently on the floral apex, the chamber in which the ovules develop is called a locule. The style, is a pillar-like stalk through which pollen tubes grow to reach the ovary, some flowers such as Tulipa do not have a distinct style, and the stigma sits directly on the ovary. The style is a tube in some plants such as lilies. The stigma, is found at the tip of the style. It is commonly sticky or feathery to capture pollen, the word pistil comes from Latin pistillum meaning pestle. A sterile pistil in a flower is referred to as a pistillode. The pistils of a flower are considered to be composed of carpels, a carpel is a theoretical construct interpreted as modified leaves bearing structures called ovules, inside which the egg cells ultimately form. A pistil may consist of one carpel, with its ovary, style and stigma, or several carpels may be joined together with a single ovary, the gynoecium may consist of one or more uni-carpellate pistils, or of one multi-carpellate pistil. The number of carpels is described by such as tricarpellate
