1.
Spiranthes spiralis
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Spiranthes spiralis, commonly known as autumn ladys-tresses, is an orchid that grows in Europe and adjacent North Africa and Asia. It is a small grey-green plant and it forms a rosette of four to five pointed, sessile, ovate leaves about 3 cm in length. In late summer an unbranched stem of about 10–15 cm tall is produced approximately four sheath-shaped leaves. The white flowers about 5mm long have a spot on the lower lip and are arranged in a helix around the upper half of the stalk. The species is listed in Appendix II of CITES as a species that is not currently threatened with extinction, Autumn ladys-tresses are legally protected in Belgium and the Netherlands. Autumn ladys tresses is a polycarp, perennial, herbaceous plant that remains underground during its dormancy in summer with tubers. Underground there are two to four, egg-shaped or ovate-oblong, hard tubers which are usually 1–3 cm long and ¾-1½ cm in diameter and they are pale brown and smooth with short transparent hairs on the outside. These tubers, as in many orchids, have a musty smell. There are no thick filamentous secondary roots as in other orchids. The plant needs many years to large enough to produce above-ground parts. Even then, it mostly flowers ones every few years, the stem is grayish green, usually 7-20 cm high, unbranched, erect, and terete. Especially further up, the stem is covered with short transparent glandular hairs, below the flowers stand three to seven grayish green, acute leaves that envelop the stem, with membranous edges and three to five veins. Sometimes the withered leaf remains of the rosette of the year are still visible at the base of the stem. The new leaves, which appear at the time or after the flower stem. They are 2-4 cm long and ¾-1¾ cm wide, blue-green, very glossy, sessile, oval and have a pointed tip and they have three to five keeled veins. Plants in the Mediterranean can be more robust than those in Western. The inflorescence is a spike of 3-12 cm long, with usually ten to twenty-five flowers. They are set in a row, usually in a clockwise or counterclockwise spiral winding around the axis
2.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
3.
Plant
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Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. The term is generally limited to the green plants, which form an unranked clade Viridiplantae. This includes the plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants have cell walls containing cellulose and obtain most of their energy from sunlight via photosynthesis by primary chloroplasts and their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic and have lost the ability to produce amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although reproduction is also common. There are about 300–315 thousand species of plants, of which the great majority, green plants provide most of the worlds molecular oxygen and are the basis of most of Earths ecologies, especially on land. Plants that produce grains, fruits and vegetables form humankinds basic foodstuffs, Plants play many roles in culture. They are used as ornaments and, until recently and in variety, they have served as the source of most medicines. The scientific study of plants is known as botany, a branch of biology, Plants are one of the two groups into which all living things were traditionally divided, the other is animals. The division goes back at least as far as Aristotle, who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus created the basis of the system of scientific classification. Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, however, these organisms are still often considered plants, particularly in popular contexts. When the name Plantae or plant is applied to a group of organisms or taxon. The evolutionary history of plants is not yet settled. Those which have been called plants are in bold, the way in which the groups of green algae are combined and named varies considerably between authors. Algae comprise several different groups of organisms which produce energy through photosynthesis, most conspicuous among the algae are the seaweeds, multicellular algae that may roughly resemble land plants, but are classified among the brown, red and green algae. Each of these groups also includes various microscopic and single-celled organisms
4.
Flowering plant
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The flowering plants, also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 416 families, approx. 13,164 known genera and a total of c.295,383 known species, etymologically, angiosperm means a plant that produces seeds within an enclosure, in other words, a fruiting plant. The term angiosperm comes from the Greek composite word meaning enclosed seeds, the ancestors of flowering plants diverged from gymnosperms in the Triassic Period, during the range 245 to 202 million years ago, and the first flowering plants are known from 160 mya. They diversified extensively during the Lower Cretaceous, became widespread by 120 mya, angiosperms differ from other seed plants in several ways, described in the table. These distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants, the amount and complexity of tissue-formation in flowering plants exceeds that of gymnosperms. The vascular bundles of the stem are arranged such that the xylem and phloem form concentric rings, in the dicotyledons, the bundles in the very young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium, the soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Among the monocotyledons, the bundles are more numerous in the stem and are scattered through the ground tissue. They contain no cambium and once formed the stem increases in diameter only in exceptional cases, the characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, and provide the most trustworthy external characteristics for establishing relationships among angiosperm species, the function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The floral apparatus may arise terminally on a shoot or from the axil of a leaf, occasionally, as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. There are two kinds of cells produced by flowers. Microspores, which divide to become pollen grains, are the male cells and are borne in the stamens. The female cells called megaspores, which divide to become the egg cell, are contained in the ovule. The flower may consist only of parts, as in willow. Usually, other structures are present and serve to protect the sporophylls, the individual members of these surrounding structures are known as sepals and petals. The outer series is usually green and leaf-like, and functions to protect the rest of the flower, the inner series is, in general, white or brightly colored, and is more delicate in structure. It functions to attract insect or bird pollinators, attraction is effected by color, scent, and nectar, which may be secreted in some part of the flower
5.
Monocotyledon
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Monocotyledons, commonly referred to as monocots, are flowering plants whose seeds typically contain only one embryonic leaf, or cotyledon. However, molecular research has shown that while the monocots form a monophyletic group or clade. Monocots have almost always recognized as a group, but with various taxonomic ranks. The APG III system of 2009 recognises a clade called monocots, the monocots include about 60,000 species. The largest family in this group by number of species are the orchids, about half as many species belong to the true grasses, which are economically the most important family of monocots. In agriculture the majority of the biomass produced comes from monocots and these include not only major grains, but also forage grasses, sugar cane, and the bamboos. Other economically important monocot crops include various palms, bananas, gingers and their relatives, turmeric and cardamom, asparagus and the onions and garlic family. Additionally most of the bulbs, plants cultivated for their blooms, such as lilies, daffodils, irises, amaryllis, cannas, bluebells. The monocots or monocotyledons have, as the name implies, a single cotyledon, or embryonic leaf, from a diagnostic point of view the number of cotyledons is neither a particularly useful characteristic, nor is it completely reliable. Nevertheless, monocots are sufficiently distinctive that there has rarely been disagreement as to membership of this group, however, morphological features that reliably characterise major clades are rare. Thus monocots are distinguishable from other angiosperms both in terms of their uniformity and diversity, although largely herbaceous, some arboraceous monocots reach great height, length and mass. The latter include agaves, palms, pandans, and bamboos and this creates challenges in water transport that monocots deal with in various ways. Some such as species of Yucca develop anomalous secondary growth, while palm trees, the axis undergoes primary thickening, that progresses from internode to internode, resulting in a typical inverted conical shape of the basal primary axis. The limited conductivity also contributes to limited branching of the stems, despite these limitations a wide variety of adaptive growth forms has resulted from epiphytic orchids and bromeliads to submarine Alismatales and mycotrophic Burmanniaceae and Triuridaceae. Other monocots, particularly Poales have adopted a life form. Leaves The cotyledon, the primordial Angiosperm leaf consists of a proximal leaf base or hypophyll, in moncots the hypophyll tends to be the dominant part in contrast to other angiosperms. Mature monocot leaves are narrow and linear, forming a sheathing around the stem at its base. There is usually only one leaf per node because the leaf base encompasses more than half the circumference, the evolution of this monocot characteristic has been attributed to developmental differences in early zonal differentiation rather than meristem activity
6.
Asparagales
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Asparagales is an order of plants in modern classification systems such as the Angiosperm Phylogeny Group and the Angiosperm Phylogeny Web. The order takes its name from the type family Asparagaceae and is placed in the monocots amongst the lilioid monocots, the order has only recently been recognized in classification systems. It was first put forward by Huber in 1977 and later taken up in the Dahlgren system of 1985 and then the APG in 1998,2003 and 2009. Before this, many of its families were assigned to the old order Liliales, DNA sequence analysis indicated that many of the taxa previously included in Liliales should actually be redistributed over three orders, Liliales, Asparagales and Dioscoreales. The boundaries of the Asparagales and of its families have undergone a series of changes in recent years, future research may lead to further changes and ultimately greater stability. In the APG circumscription, Asparagales is the largest order of monocots with 14 families,1,122 genera, the order is clearly circumscribed on the basis of molecular phylogenetics, but is difficult to define morphologically, since its members are structurally diverse. Most species of Asparagales are herbaceous perennials, although some are climbers, the order also contains many geophytes. According to telomere sequence, at least two evolutionary switch-points happened within the order, basal sequence is formed by TTTAGGG like in majority of higher plants. Basal motif was changed to vertebrate-like TTAGGG and finally the most divergent motif CTCGGTTATGGG appears in Allium, one of the defining characteristics of the order is the presence of phytomelanin, a black pigment present in the seed coat, creating a dark crust. Phytomelanin is found in most families of the Asparagales, the leaves of almost all species form a tight rosette, either at the base of the plant or at the end of the stem, but occasionally along the stem. The flowers are not particularly distinctive, being lily type, with six tepals, from an economic point of view, the order Asparagales is second in importance within the monocots to the order Poales. Species are used as food and flavourings, as cut flowers, and as garden ornamentals. Thus although most species in the order are herbaceous, some no more than 15 cm high, there are a number of climbers, as well as several genera forming trees, succulent genera occur in several families. Almost all species have a cluster of leaves, either at the base of the plant or at the end of a more-or-less woody stem as with Yucca. In some cases the leaves are produced along the stem, the flowers are in the main not particularly distinctive, being of a general lily type, with six tepals, either free or fused from the base and up to six stamina. They are frequently clustered at the end of the plant stem and they are generally geophytes, but with linear leaves, and a lack of fine reticular venation. The seeds characteristically have the external epidermis either obliterated, or if present, have a layer of black carbonaceous phytomelanin in species with dry fruits. The inner part of the coat is generally collapsed, in contrast to Liliales whose seeds have a well developed outer epidermis, lack phytomelanin
7.
Orchidaceae
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The Orchidaceae are a diverse and widespread family of flowering plants, with blooms that are often colourful and often fragrant, commonly known as the orchid family. Along with the Asteraceae, they are one of the two largest families of flowering plants, the Orchidaceae have about 28,000 currently accepted species, distributed in about 763 genera. The determination of which family is larger is still under debate, regardless, the number of orchid species nearly equals the number of bony fishes and is more than twice the number of bird species, and about four times the number of mammal species. The family also encompasses about 6–11% of all seed plants, the largest genera are Bulbophyllum, Epidendrum, Dendrobium and Pleurothallis. The family also includes Vanilla, Orchis, and many cultivated plants such as Phalaenopsis. Moreover, since the introduction of species into cultivation in the 19th century, horticulturists have produced more than 100,000 hybrids. Orchids are easily distinguished from plants, as they share some very evident, shared derived characteristics. Among these are, bilateral symmetry of the flower, many flowers, a nearly always highly modified petal, fused stamens and carpels. All orchids are perennial herbs that lack any permanent woody structure and they can grow according to two patterns, Monopodial, The stem grows from a single bud, leaves are added from the apex each year and the stem grows longer accordingly. The stem of orchids with a monopodial growth can reach several metres in length, as in Vanda, Sympodial, Sympodial orchids have a front and a back. The plant produces a series of adjacent shoots which grow to a size, bloom. Sympodial orchids grow laterally rather than vertically, following the surface of their support, the growth continues by development of new leads, with their own leaves and roots, sprouting from or next to those of the previous year, as in Cattleya. While a new lead is developing, the rhizome may start its growth again from a so-called eye, Sympodial orchids may have visible pseudobulbs joined by a rhizome, which creeps along the top or just beneath the soil. Terrestrial orchids may be rhizomatous or form corms or tubers, the root caps of terrestrial orchids are smooth and white. Some sympodial terrestrial orchids, such as Orchis and Ophrys, have two subterranean tuberous roots, one is used as a food reserve for wintry periods, and provides for the development of the other one, from which visible growth develops. In warm and constantly humid climates, many terrestrial orchids do not need pseudobulbs, epiphytic orchids, those that grow upon a support, have modified aerial roots that can sometimes be a few meters long. In the older parts of the roots, a modified spongy epidermis and it is made of dead cells and can have a silvery-grey, white or brown appearance. In some orchids, the velamen includes spongy and fibrous bodies near the passage cells, the cells of the root epidermis grow at a right angle to the axis of the root to allow them to get a firm grasp on their support
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.
Inflorescence
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An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the part of the shoot of seed plants where flowers are formed. Inflorescence can also be defined as the portion of a plant that bears a cluster of flowers in a specific pattern. The stem holding the whole inflorescence is called a peduncle and the major axis holding the flowers or more branches within the inflorescence is called the rachis, the stalk of each single flower is called a pedicel. A flower that is not part of an inflorescence is called a solitary flower, any flower in an inflorescence may be referred to as a floret, especially when the individual flowers are particularly small and borne in a tight cluster, such as in a pseudanthium. The fruiting stage of an inflorescence is known as an infructescence, inflorescences may be simple or complex. The rachis may be one of several types, including Single, Composite, Umbel and these terms are general representations as plants in nature can have a combination of types. Inflorescences usually have modified shoots foliage different from the part of the plant. Considering the broadest meaning of the term, any leaf associated with an inflorescence is called a bract. A bract is usually located at the node where the stem of the inflorescence forms, joined to the main stem of the plant. They serve a variety of functions which include attracting pollinators and protecting young flowers, according to the presence or absence of bracts and their characteristics we can distinguish, Ebracteate inflorescences, No bracts in the inflorescence. Bracteate inflorescences, The bracts in the inflorescence are very specialised, sometimes reduced to small scales and this use is not technically correct, as, despite their normal appearance, these leaves are considered, in fact, bracts, so that leafy inflorescence is preferable. Leafy-bracted inflorescences, Intermediate between bracteate and leafy inflorescence, if many bracts are present and they are strictly connected to the stem, like in the family Asteraceae, the bracts might collectively be called an involucre. If the inflorescence has a unit of bracts further up the stem. Plant organs can grow according to two different schemes, namely monopodial or racemose and sympodial or cymose, the terminal bud keeps growing and forming lateral flowers. A terminal flower is never formed, the terminal bud forms a terminal flower and then dies out. Other flowers then grow from lateral buds, indeterminate and determinate inflorescences are sometimes referred to as open and closed inflorescences respectively. In an indeterminate inflorescence there is no true terminal flower and the stem usually has a rudimentary end, in many cases the last true flower formed by the terminal bud straightens up, appearing to be a terminal flower
10.
Tepal
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A tepal is one of the outer parts of a flower when these parts cannot easily be divided into two kinds, sepals and petals. The term was first proposed by Augustin Pyramus de Candolle in 1827, undifferentiated tepals are believed to be the ancestral condition in flowering plants. For example, Amborella, which is thought to have separated earliest in the evolution of flowering plants, has flowers with undifferentiated tepals, distinct petals and sepals would therefore have arisen by differentiation, probably in response to animal pollination. Tepals formed by similar sepals and petals are common in monocotyledons, in tulips, for example, the first and second whorls both contain structures that look like petals. These are fused at the base to one large, showy. In lilies the organs in the first whorl are separate from the second, where sepals and petals can in principle be distinguished, usage of the term tepal is not always consistent – some authors will refer to sepals and petals where others use tepals in the same context. In some plants the flowers have no petals, and all the tepals are sepals modified to look like petals and these organs are described as petaloid, for example, the sepals of hellebores. When the undifferentiated tepals resemble petals, they are referred to as petaloid, as in petaloid monocots. Since they include Liliales, a name is lilioid monocots. Terms used in the description of tepals include pubescent, puberulent, tepal shape is described in similar terms to those used for leaves. Plant Systematics - Jones, Samuel - McGraw-Hill 1979 ISBN 0-07-032795-5
11.
Gansu
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Gansu is a province of the Peoples Republic of China, located in the northwest of the country. It lies between the Tibetan and Loess plateaus, and borders Mongolia, Inner Mongolia, and Ningxia to the north, Xinjiang and Qinghai to the west, Sichuan to the south, the Yellow River passes through the southern part of the province. Gansu has a population of 26 million and covers an area of 425,800 square kilometres, the capital is Lanzhou, located in the southeast part of the province. Gansu is a compound of the names of Ganzhou and Suzhou, Gansu is abbreviated as 甘 or 陇, and is also known as Longxi or Longyou, in reference to the Long Mountain east of Gansu. Gansu is a name first used during the Song dynasty of two Sui and Tang dynasty prefectures, Gan and Su. In prehistoric times, Gansu was host to Neolithic cultures, the Dadiwan culture, from where archaeologically significant artifacts have been excavated, flourished in the eastern end of Gansu from about 6000 BC to about 3000 BC. The Majiayao culture and part of the Qijia culture took root in Gansu from 3100 BC to 2700 BC and 2400 BC to 1900 BC respectively, the Yuezhi originally lived in the very western part of Gansu until they were forced to emigrate by the Xiongnu around 177 BCE. The State of Qin, later to become the state of the Chinese empire, grew out from the southeastern part of Gansu. The Qin name is believed to have originated, in part, Qin tombs and artifacts have been excavated from Fangmatan near Tianshui, including one 2200-year-old map of Guixian County. In imperial times, Gansu was an important strategic outpost and communications link for the Chinese empire, the Han dynasty extended the Great Wall across this corridor, building the strategic Yumenguan and Yangguan fort towns along it. Remains of the wall and the towns can be found there, the Ming dynasty built the Jiayuguan outpost in Gansu. By the Qingshui treaty, concluded in 823 between the Tibetan Empire and the Tang dynasty, China lost a part of Gansu province for a significant period. After the fall of the Uyghur Empire, an Uyghur state was established in parts of Gansu that lasted from 848 to 1036 AD, during that time, many of Gansus residents were converted to Islam. Along the Silk Road, Gansu was an important province. Temples and Buddhist grottoes such as those at Mogao Caves and Maijishan Caves contain artistically and historically revealing murals. An early form of paper inscribed with Chinese characters and dating to about 8 BC was discovered at the site of a Western Han garrison near the Yumen pass in August 2006, the province was also the origin of the Dungan Revolt of 1862-77. Among the Qing forces were Muslim generals like Ma Zhanao and Ma Anliang who helped Qing crush the rebel Muslims, the revolt spread into Gansu from neighbouring Qinghai. Frequent earthquakes, droughts and famines have tended to slow progress of the province until recently
12.
Hybrid (biology)
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In biology, a hybrid, also known as a cross breed, is the result of combining, through sexual reproduction, the qualities of two animals or plants of different breeds, varieties, species or genera. Hybrids are not always intermediate between their parents, but can show heterosis or hybrid vigour, often growing larger or taller than either parent, some act before fertilization, others after it. A few animal species and many plant species, however, are the result of hybrid speciation, doubling the number of chromosomes to create polyploids is important in hybrid speciation, because homoploid hybrids are rarely fertile, the polyploid hybrids are allopolyploids. Human impact on the environment has greatly increased the mixing of species, with introduced species worldwide, the genetic mixing may threaten many species with extinction, while genetic erosion in crop plants may be damaging the gene pools of many species for future breeding. Many commercially useful fruits, flowers, garden herbs and trees have been produced by hybridization, one flower, Oenothera lamarckiana, was central to early genetics research into polyploidy. The term hybrid is derived from Latin hybrida, used for such as of a tame sow and a wild boar, or the child of a freeman. The term came into use in English in the 19th century. Conspicuous hybrids are named with portmanteau words, starting in the 1920s with the breeding of tiger-lion hybrids. The cross between two different homozygous lines produces an F1 hybrid that is heterozygous, having two alleles, one contributed by each parent and typically one is dominant and the other recessive. Typically, the F1 generation is also phenotypically homogeneous, producing offspring that are all similar to each other, double cross hybrids result from the cross between two different F1 hybrids. Three-way cross hybrids result from the cross between an F1 hybrid and an inbred line, triple cross hybrids result from the crossing of two different three-way cross hybrids. Top cross hybrids result from the crossing of a top quality or pure-bred male, population hybrids result from the crossing of plants or animals in a population with those of another population. These include interspecific hybrids or crosses between different breeds. e, from the point of view of genetics, different kinds of hybrid can be distinguished as follows, A genetic hybrid carries two different alleles of the same gene. A structural hybrid results from the fusion of gametes that have differing structure in at least one chromosome, a numerical hybrid results from the fusion of gametes having different haploid numbers of chromosomes. A permanent hybrid results when only the heterozygous genotype occurs, as in Oenothera lamarckiana, from the point of view of taxonomy, hybrids differ according to their parentage, Hybrids between different subspecies are called intra-specific hybrids. Offspring resulting from interspecies mating, are called interspecific hybrids, these result in hybrid speciation. Intergeneric hybrids result from matings between different genera, such as sheep and goats. Interfamilial hybrids such as chickens and guineafowl or pheasants are reliably described but extremely rare
Media related to Spiranthes at Wikimedia Commons
Data related to Spiranthes at Wikispecies
