The term cultivar most refers to an assemblage of plants selected for desirable characters that are maintained during propagation. More cultivar refers to the most basic classification category of cultivated plants in the International Code of Nomenclature for Cultivated Plants. Most cultivars arose in cultivation. Popular ornamental garden plants like roses, daffodils and azaleas are cultivars produced by careful breeding and selection for floral colour and form; the world's agricultural food crops are exclusively cultivars that have been selected for characters such as improved yield and resistance to disease, few wild plants are now used as food sources. Trees used in forestry are special selections grown for their enhanced quality and yield of timber. Cultivars form a major part of Liberty Hyde Bailey's broader group, the cultigen, defined as a plant whose origin or selection is due to intentional human activity. A cultivar is not the same as a botanical variety, a taxonomic rank below subspecies, there are differences in the rules for creating and using the names of botanical varieties and cultivars.
In recent times, the naming of cultivars has been complicated by the use of statutory patents for plants and recognition of plant breeders' rights. The International Union for the Protection of New Varieties of Plants offers legal protection of plant cultivars to persons or organisations that introduce new cultivars to commerce. UPOV requires that a cultivar be "distinct, uniform", "stable". To be "distinct", it must have characters that distinguish it from any other known cultivar. To be "uniform" and "stable", the cultivar must retain these characters in repeated propagation; the naming of cultivars is an important aspect of cultivated plant taxonomy, the correct naming of a cultivar is prescribed by the Rules and Recommendations of the International Code of Nomenclature for Cultivated Plants. A cultivar is given a cultivar name, which consists of the scientific Latin botanical name followed by a cultivar epithet; the cultivar epithet is in a vernacular language. For example, the full cultivar name of the King Edward potato is Solanum tuberosum'King Edward'.'King Edward' is the cultivar epithet, according to the Rules of the Cultivated Plant Code, is bounded by single quotation marks.
The word cultivar originated from the need to distinguish between wild plants and those with characteristics that arose in cultivation, presently denominated cultigens. This distinction dates to the Greek philosopher Theophrastus, the "Father of Botany", keenly aware of this difference. Botanical historian Alan Morton noted that Theophrastus in his Historia Plantarum "had an inkling of the limits of culturally induced changes and of the importance of genetic constitution"; the International Code of Nomenclature for algae and plants uses as its starting point for modern botanical nomenclature the Latin names in Linnaeus' Species Plantarum and Genera Plantarum. In Species Plantarum, Linnaeus enumerated all plants known to him, either directly or from his extensive reading, he recognised the rank of varietas and he indicated these varieties with letters of the Greek alphabet, such as α, β, λ, before the varietal name, rather than using the abbreviation "var." as is the present convention. Most of the varieties that Linnaeus enumerated were of "garden" origin rather than being wild plants.
In time the need to distinguish between wild plants and those with variations, cultivated increased. In the nineteenth century many "garden-derived" plants were given horticultural names, sometimes in Latin and sometimes in a vernacular language. From circa the 1900s, cultivated plants in Europe were recognised in the Scandinavian and Slavic literature as stamm or sorte, but these words could not be used internationally because, by international agreement, any new denominations had to be in Latin. In the twentieth century an improved international nomenclature was proposed for cultivated plants. Liberty Hyde Bailey of Cornell University in New York, United States created the word cultivar in 1923 when he wrote that: The cultigen is a species, or its equivalent, that has appeared under domestication – the plant is cultigenous. I now propose another name, for a botanical variety, or for a race subordinate to species, that has originated under cultivation, it is the equivalent of the botanical variety except in respect to its origin.
In that essay, Bailey used only the rank of species for the cultigen, but it was obvious to him that many domesticated plants were more like botanical varieties than species, that realization appears to have motivated the suggestion of the new category of cultivar. Bailey created the word cultivar, assumed to be a portmanteau of cultivated and variety. Bailey never explicitly stated the etymology of cultivar, it has been suggested that it is instead a contraction of cultigen and variety, which seems correct; the neologism cultivar was promoted as "euphonious" and "free from ambiguity". The first Cultivated Plant Code of 1953 subsequently commended its use, by 1960 it had achieved common international acceptance; the words cultigen and cultivar may be confused with
Agriculture is the science and art of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in cities; the history of agriculture began thousands of years ago. After gathering wild grains beginning at least 105,000 years ago, nascent farmers began to plant them around 11,500 years ago. Pigs and cattle were domesticated over 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. Industrial agriculture based on large-scale monoculture in the twentieth century came to dominate agricultural output, though about 2 billion people still depended on subsistence agriculture into the twenty-first. Modern agronomy, plant breeding, agrochemicals such as pesticides and fertilizers, technological developments have increased yields, while causing widespread ecological and environmental damage. Selective breeding and modern practices in animal husbandry have increased the output of meat, but have raised concerns about animal welfare and environmental damage.
Environmental issues include contributions to global warming, depletion of aquifers, antibiotic resistance, growth hormones in industrial meat production. Genetically modified organisms are used, although some are banned in certain countries; the major agricultural products can be broadly grouped into foods, fibers and raw materials. Food classes include cereals, fruits, meat, milk and eggs. Over one-third of the world's workers are employed in agriculture, second only to the service sector, although the number of agricultural workers in developed countries has decreased over the centuries; the word agriculture is a late Middle English adaptation of Latin agricultūra, from ager, "field", which in its turn came from Greek αγρός, cultūra, "cultivation" or "growing". While agriculture refers to human activities, certain species of ant and ambrosia beetle cultivate crops. Agriculture is defined with varying scopes, in its broadest sense using natural resources to "produce commodities which maintain life, including food, forest products, horticultural crops, their related services".
Thus defined, it includes arable farming, animal husbandry and forestry, but horticulture and forestry are in practice excluded. The development of agriculture enabled the human population to grow many times larger than could be sustained by hunting and gathering. Agriculture began independently in different parts of the globe, included a diverse range of taxa, in at least 11 separate centres of origin. Wild grains were eaten from at least 105,000 years ago. From around 11,500 years ago, the eight Neolithic founder crops and einkorn wheat, hulled barley, lentils, bitter vetch, chick peas and flax were cultivated in the Levant. Rice was domesticated in China between 11,500 and 6,200 BC with the earliest known cultivation from 5,700 BC, followed by mung and azuki beans. Sheep were domesticated in Mesopotamia between 11,000 years ago. Cattle were domesticated from the wild aurochs in the areas of modern Turkey and Pakistan some 10,500 years ago. Pig production emerged in Eurasia, including Europe, East Asia and Southwest Asia, where wild boar were first domesticated about 10,500 years ago.
In the Andes of South America, the potato was domesticated between 10,000 and 7,000 years ago, along with beans, llamas and guinea pigs. Sugarcane and some root vegetables were domesticated in New Guinea around 9,000 years ago. Sorghum was domesticated in the Sahel region of Africa by 7,000 years ago. Cotton was domesticated in Peru by 5,600 years ago, was independently domesticated in Eurasia. In Mesoamerica, wild teosinte was bred into maize by 6,000 years ago. Scholars have offered multiple hypotheses to explain the historical origins of agriculture. Studies of the transition from hunter-gatherer to agricultural societies indicate an initial period of intensification and increasing sedentism. Wild stands, harvested started to be planted, came to be domesticated. In Eurasia, the Sumerians started to live in villages from about 8,000 BC, relying on the Tigris and Euphrates rivers and a canal system for irrigation. Ploughs appear in pictographs around 3,000 BC. Farmers grew wheat, vegetables such as lentils and onions, fruits including dates and figs.
Ancient Egyptian agriculture relied on its seasonal flooding. Farming started in the predynastic period at the end of the Paleolithic, after 10,000 BC. Staple food crops were grains such as wheat and barley, alongside industrial crops such as flax and papyrus. In India, wheat and jujube were domesticated by 9,000 BC, soon followed by sheep and goats. Cattle and goats were domesticated in Mehrgarh culture by 8,000–6,000 BC. Cotton was cultivated by the 5th-4th millennium BC. Archeological evidence indicates an animal-drawn plough from 2,500 BC in the Indus Valley Civilisation. In China, from the 5th century BC there was a nationwide granary system and widespread silk farming. Water-powered grain mills were in use followed by irrigation. By the late 2nd century, heavy ploughs had been developed with iron mouldboards; these spread westwards across Eurasia. Asian rice was domesticated 8,200–13,500 years ago – depending on the molecular clock estimate, used – on the Pearl River in southern China with a single genetic origin from the wild rice Oryza rufipogon
Horticulture has been defined as the culture of plants for food and beauty. A more precise definition can be given as "The cultivation and sale of fruits, vegetables, ornamental plants, flowers as well as many additional services", it includes plant conservation, landscape restoration, soil management and garden design and maintenance, arboriculture. In contrast to agriculture, horticulture does not include large-scale crop production or animal husbandry. Horticulturists apply their knowledge and technologies used to grow intensively produced plants for human food and non-food uses and for personal or social needs, their work involves plant propagation and cultivation with the aim of improving plant growth, quality, nutritional value, resistance to insects and environmental stresses. They work as gardeners, therapists and technical advisors in the food and non-food sectors of horticulture. Horticulture refers to the growing of plants in a field or garden; the word horticulture is modeled after agriculture, comes from the Latin hortus "garden" and cultūra "cultivation", from cultus, the perfect passive participle of the verb colō "I cultivate".
Hortus is cognate with the native English word yard and the borrowed word garden. The major areas of Horticulture include: Arboriculture is the study of, the selection, plant and removal of, individual trees, shrubs and other perennial woody plants. Turf management includes all aspects of the production and maintenance of turf grass for sports, leisure use or amenity use. Floriculture includes the marketing of floral crops. Study of flower cultivation. Landscape horticulture includes the production and maintenance of landscape plants. Olericulture includes the marketing of vegetables. Pomology includes the marketing of pome fruits. Viticulture includes the marketing of grapes. Oenology includes all aspects of winemaking. Postharvest physiology involves maintaining the quality of and preventing the spoilage of plants and animals. Horticulture has a long history; the study and science of horticulture dates all the way back to the times of Cyrus the Great of ancient Persia, has been going on since, with present-day horticulturists such as Freeman S. Howlett and Luther Burbank.
The practice of horticulture can be retraced for many thousands of years. The cultivation of taro and yam in Papua New Guinea dates back to at least 6950–6440 cal BP; the origins of horticulture lie in the transition of human communities from nomadic hunter-gatherers to sedentary or semi-sedentary horticultural communities, cultivating a variety of crops on a small scale around their dwellings or in specialized plots visited during migrations from one area to the next. In the Pre-Columbian Amazon Rainforest, natives are believed to have used biochar to enhance soil productivity by smoldering plant waste. European settlers called it Terra Preta de Indio. In forest areas such horticulture is carried out in swiddens. A characteristic of horticultural communities is that useful trees are to be found planted around communities or specially retained from the natural ecosystem. Horticulture differs from agriculture in two ways. First, it encompasses a smaller scale of cultivation, using small plots of mixed crops rather than large fields of single crops.
Secondly, horticultural cultivations include a wide variety of crops including fruit trees with ground crops. Agricultural cultivations however as a rule focus on one primary crop. In pre-contact North America the semi-sedentary horticultural communities of the Eastern Woodlands contrasted markedly with the mobile hunter-gatherer communities of the Plains people. In Central America, Maya horticulture involved augmentation of the forest with useful trees such as papaya, cacao and sapodilla. In the cornfields, multiple crops were grown such as beans, squash and chilli peppers, in some cultures tended or by women. Since 1804 The Royal Horticultural Society, a UK charity, leads on the encouragement and improvement of the science and practice of horticulture in all its branches and shares this knowledge through its community and learning programmes, world class gardens and shows; the oldest Horticultural society in the world, founded in 1768, is the Ancient Society of York Florists. They still have four shows a year in York, UK.
The professional body representing horticulturists in Great Britain and Ireland is the Institute of Horticulture. The IOH has an international branch for members outside of these islands; the International Society for Horticultural Science promotes and encourages research and education in all branches of horticultural science. The American Society of Horticultural Science promotes and encourages research and education in all branches of horticultural science in the Americas; the Australian Society of Horticultural Science was established in 1990 as a professional society for the promotion and enhancement of Australian horticultural science and industry. The National Junior Horticultural Association was established in 1934 and was the first organisation in the world dedicated to youth and horticulture. NJHA programs are designed to help young people obtain a basic understanding of, develop skills in, the ever-expanding art and science of horticulture; the New Zealand Horticulture Institute. The Global Horticulture Initiative (GlobalHo
Lilium is a genus of herbaceous flowering plants growing from bulbs, all with large prominent flowers. Lilies are a group of flowering plants which are important in culture and literature in much of the world. Most species are native to the temperate northern hemisphere, though their range extends into the northern subtropics. Many other plants are not related to true lilies. Lilies are tall perennials ranging in height from 2–6 ft, they form naked or tunicless scaly underground bulbs which are their organs of perennation. In some North American species the base of the bulb develops into rhizomes, on which numerous small bulbs are found; some species develop stolons. Most bulbs are buried deep in the ground. Many species form stem-roots. With these, the bulb grows at some depth in the soil, each year the new stem puts out adventitious roots above the bulb as it emerges from the soil; these roots are in addition to the basal roots. The flowers are large fragrant, come in a wide range of colors including whites, oranges, pinks and purples.
Markings include spots and brush strokes. The plants are late spring- or summer-flowering. Flowers are borne in racemes or umbels at the tip of the stem, with six tepals spreading or reflexed, to give flowers varying from funnel shape to a "Turk's cap"; the tepals are free from each other, bear a nectary at the base of each flower. The ovary borne above the point of attachment of the anthers; the fruit is a three-celled capsule. Seeds ripen in late summer, they exhibit varying and sometimes complex germination patterns, many adapted to cool temperate climates. Most cool temperate species are deciduous and dormant in winter in their native environment, but a few species which distribute in hot summer and mild winter area lose leaves and remain short dormant in Summer or Autumn, sprout from Autumn to winter, forming dwarf stem bearing a basal rosette of leaves until, after they have received sufficient chilling, the stem begins to elongate in warming weather. The basic chromosome number is twelve.
Taxonomical division in sections follows the classical division of Comber, species acceptance follows the World Checklist of Selected Plant Families, the taxonomy of section Pseudolirium is from the Flora of North America, the taxonomy of Section Liriotypus is given in consideration of Resetnik et al. 2007, the taxonomy of Chinese species follows the Flora of China and the taxonomy of Section Sinomartagon follows Nishikawa et al. as does the taxonomy of Section Archelirion. The World Checklist of Selected Plant Families, as of January 2014, considers Nomocharis a separate genus in its own right, however some authorities consider Nomocharis to be embedded within Lilium, rather than treat it as a separate genus. There are seven sections: Martagon Pseudolirium Liriotypus Archelirion Sinomartagon Leucolirion DaurolirionFor a full list of accepted species with their native ranges, see List of Lilium species Some species included within this genus have now been placed in other genera; these genera include Cardiocrinum, Notholirion and Fritillaria.
The botanic name Lilium is a Linnaean name. The Latin name is derived from the Greek λείριον, leírion assumed to refer to true, white lilies as exemplified by the Madonna lily; the word was borrowed from Coptic hleri, from standard hreri, from Demotic hrry, from Egyptian hrṛt "flower". Meillet maintains that both the Egyptian and the Greek word are possible loans from an extinct, substratum language of the Eastern Mediterranean; the Greeks used the word κρῖνον, krīnon, albeit for non-white lilies. The term "lily" has in the past been applied to numerous flowering plants with only superficial resemblance to the true lily, including water lily, fire lily, lily of the Nile, calla lily, trout lily, kaffir lily, cobra lily, lily of the valley, ginger lily, Amazon lily, leek lily, Peruvian lily, others. All English translations of the Bible render the Hebrew shūshan, shōshan, shōshannā as "lily", but the "lily among the thorns" of Song of Solomon, for instance, may be the honeysuckle. For a list of other species described as lilies, see Lily.
The range of lilies in the Old World extends across much of Europe, across most of Asia to Japan, south to India, east to Indochina and the Philippines. In the New World they extend from southern Canada through much of the United States, they are adapted to either woodland habitats montane, or sometimes to grassland habitats. A few can survive in marshland and epiphytes are known in tropical southeast Asia. In general they prefer moderately lime-free soils. Lilies are used as food plants by the larvae of some Lepidoptera species including the Dun-bar. Many species are grown in the garden in temperate and sub-tropical regions, they may be grown as potted plants. Numerous ornamental hybrids have been developed, they can be used in herbaceous borders and shrub plantings, as patio plants. Some lilies Lilium longiflorum, form important cut flower crops; these may be forced for particular markets. Lilies are planted as bulbs in the dormant season, they are best planted in a south-facing sloping aspect, in sun or part shade, at a depth 2½ times the height of the bulb.
Most prefer a porous, loamy soil
Polyploidy is the state of a cell or organism having more than two paired sets of chromosomes. Most species whose cells have nuclei are diploid, meaning they have two sets of chromosomes—one set inherited from each parent. However, polyploidy is found in some organisms and is common in plants. In addition, polyploidy occurs in some tissues of animals that are otherwise diploid, such as human muscle tissues; this is known as endopolyploidy. Species whose cells do not have nuclei, that is, may be polyploid, as seen in the large bacterium Epulopiscium fishelsoni. Hence ploidy is defined with respect to a cell. Most eukaryotes produce haploid gametes by meiosis. A monoploid has only one set of chromosomes, the term is only applied to cells or organisms that are diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals and multicellular algae have life cycles with two alternating multicellular generations; the gametophyte generation is haploid, produces gametes by mitosis, the sporophyte generation is diploid and produces spores by meiosis.
Polyploidy refers to a numerical change in a whole set of chromosomes. Organisms in which a particular chromosome, or chromosome segment, is under- or over-represented are said to be aneuploid. Aneuploidy refers to a numerical change in part of the chromosome set, whereas polyploidy refers to a numerical change in the whole set of chromosomes. Polyploidy may occur due to abnormal cell division, either during mitosis, or during metaphase I in meiosis. In addition, it can be induced in plants and cell cultures by some chemicals: the best known is colchicine, which can result in chromosome doubling, though its use may have other less obvious consequences as well. Oryzalin will double the existing chromosome content. Polyploidy occurs in differentiated human tissues in the liver, heart muscle, bone marrow and the placenta, it occurs in the somatic cells of some animals, such as goldfish and salamanders, but is common among ferns and flowering plants, including both wild and cultivated species. Wheat, for example, after millennia of hybridization and modification by humans, has strains that are diploid, tetraploid with the common name of durum or macaroni wheat, hexaploid with the common name of bread wheat.
Many agriculturally important plants of the genus Brassica are tetraploids. Polyploidization is a mechanism of sympatric speciation because polyploids are unable to interbreed with their diploid ancestors. An example is the plant Erythranthe peregrina. Sequencing confirmed that this species originated from E. × robertsii, a sterile triploid hybrid between E. guttata and E. lutea, both of which have been introduced and naturalised in the United Kingdom. New populations of E. peregrina arose on the Scottish mainland and the Orkney Islands via genome duplication from local populations of E. × robertsii. Because of a rare genetic mutation, E. peregrina is not sterile. Polyploid types are labeled according to the number of chromosome sets in the nucleus; the letter x is used to represent the number of chromosomes in a single set. Triploid, for example sterile saffron crocus, or seedless watermelons common in the phylum Tardigrada tetraploid, for example Salmonidae fish, the cotton Gossypium hirsutum pentaploid, for example Kenai Birch hexaploid, for example wheat, kiwifruit heptaploid or septaploid octaploid or octoploid, for example Acipenser, dahlias decaploid, for example certain strawberries dodecaploid, for example the plants Celosia argentea and Spartina anglica or the amphibian Xenopus ruwenzoriensis.
Examples in animals are more common in non-vertebrates such as flatworms and brine shrimp. Within vertebrates, examples of stable polyploidy include many cyprinids; some fish have as many as 400 chromosomes. Polyploidy occurs in amphibians. Polyploid lizards are quite common, but are sterile and must reproduce by parthenogenesis. Polyploid mole salamanders are all female and reproduce by kleptogenesis, "stealing" spermatophores from diploid males of related species to trigger egg development but not incorporating the males' DNA into the offspring. While mammalian liver cells are polyploid, rare instances of polyploid mammals are known, but most result in prenatal death. An octodontid rodent of Argentina's harsh desert regions, known as the plains viscacha rat has been reported as an exception to this'rule'. However, careful analysis using chromosome paints shows that there are only two copies of each chromosome in T. barrerae, not the four expected if it were a tetraploid. This rodent kin to guinea pigs and chinchillas.
Its "new" diploid number is 102 and so its cells are twice normal size. Its closest living relation is Octomys mimax, the Andean Viscacha-Rat of the same family, whose 2n = 56, it was therefore surmised that an Octomys-like ancestor produced tetraploid offspring that were, by virtue of their doubled chromosomes, reproductively isolated from their parents. Polyploidy was induced in fish by Har Swarup using a cold-shock treatment of the eggs close to the time o
Botanical nomenclature is the formal, scientific naming of plants. It is distinct from taxonomy. Plant taxonomy is concerned with classifying plants; the starting point for modern botanical nomenclature is Linnaeus' Species Plantarum of 1753. Botanical nomenclature is governed by the International Code of Nomenclature for algae and plants, which replaces the International Code of Botanical Nomenclature. Fossil plants are covered by the code of nomenclature. Within the limits set by that code there is another set of rules, the International Code of Nomenclature for Cultivated Plants which applies to plant cultivars that have been deliberately altered or selected by humans. Botanical nomenclature has a long history, going back beyond the period when Latin was the scientific language throughout Europe, to Theophrastus and other Greek writers. Many of these works have come down to us in Latin translations; the principal Latin writer on botany was Pliny the Elder. From Mediaeval times, Latin became the universal scientific language in Europe.
Most written plant knowledge was the property of monks Benedictine, the purpose of those early herbals was medicinal rather than plant science per se. It would require the invention of the printing press to make such information more available. Leonhart Fuchs, a German physician and botanist is considered the originator of Latin names for the increasing number of plants known to science. For instance he coined the name Digitalis in his De Historia Stirpium Commentarii Insignes. A key event was Linnaeus’ adoption of binomial names for plant species in his Species Plantarum. In the nineteenth century it became clear that there was a need for rules to govern scientific nomenclature, initiatives were taken to refine the body of laws initiated by Linnaeus; these were published in successively more sophisticated editions. For plants, key dates are 1867 and 1906; the most recent is the Melbourne Code, adopted in 2011. Another development was the insight into the delimitation of the concept of'plant'. More and more groups of organisms are being recognised as being independent of plants.
The formal names of most of these organisms are governed by the today. Some protists that do not fit into either plant or animal categories are treated under either or both of the ICN and the ICZN. A separate Code was adopted to govern the nomenclature of Bacteria, the International Code of Nomenclature of Bacteria. Botanical nomenclature is linked to plant taxonomy, botanical nomenclature serves plant taxonomy, but botanical nomenclature is separate from plant taxonomy. Botanical nomenclature is the body of rules prescribing which name applies to that taxon and if a new name may be coined. Plant taxonomy is an empirical science, a science that determines what constitutes a particular taxon: e.g. "What plants belong to this species?" and "What species belong to this genus?". The definition of the limits of a taxon is called its'circumscription'. For a particular taxon, if two taxonomists agree on its circumscription and position there is only one name which can apply under the ICN. Where they differ in opinion on any of these issues and the same plant may be placed in taxa with different names.
As an example, consider Siehe's Glory-of-the-Snow, Chionodoxa siehei: Taxonomists can disagree as to whether two groups of plants are sufficiently distinct to be put into one species or not. Thus Chionodoxa siehei and Chionodoxa forbesii have been treated as a single species by some taxonomists or as two species by others. If treated as one species, the earlier published name must be used, so plants called Chionodoxa siehei become Chionodoxa forbesii. Taxonomists can disagree as to whether two genera are sufficiently distinct to be kept separate or not. While agreeing that the genus Chionodoxa is related to the genus Scilla the bulb specialist Brian Mathew considers that their differences warrant maintaining separate genera. Others disagree, would refer to Chionodoxa siehei as Scilla siehei; the earliest published genus name must be used. Taxonomists can disagree as to the limits of families; when the Angiosperm Phylogeny Group first published its classification of the flowering plants in 1998, Chionodoxa siehei would have been placed in the family Hyacinthaceae.
In the 2009 revision of their classification, the APG no longer recognize the Hyacinthaceae as a separate family, merging it into a enlarged family Asparagaceae. Thus Chionodoxa siehei moves from the Hyacinthaceae to the Asparagaceae. Taxonomists can disagree as to the rank of a taxon. Rather than allow the Hyacinthaceae to disappear altogether, Chase et al. suggested that it be treated as a subfamily within the Asparagaceae. The ICN requires family names to end with "-aceae" and subfamily names to end with "-oideae", thus a possible name for the Hyacinthaceae when treated as a subfamily would be'Hyacinthoideae'. However, the name Scilloideae had been published in 1835 as the name for a subfamily containing the genus Scilla, so this name has priority and must be used. Hence for those taxonomists who accept the APG system of 2009, Chionodoxa siehei can be placed in the subfamily Scil
The term grex, derived from the Latin noun grex, gregis meaning'flock', has been coined to expand botanical nomenclature to describe hybrids of orchids, based on their parentage. Grex names are one of the three categories of plant names governed by the International Code of Nomenclature for Cultivated Plants; the horticultural nomenclature of grexes exists within the framework of the botanical nomenclature of hybrid plants. Interspecific hybrids occur in nature, are treated under the International Code of Nomenclature for algae and plants as nothospecies, they can optionally be given Linnean binomials with a multiplication sign "×" before the species epithet for example Crataegus × media. An offspring of a nothospecies, either with a member of the same nothospecies or any of the parental species as the other parent, has the same nothospecific name; the nothospecific binomial is an alias for a list of the ancestral species, whether the ancestry is known or not. For example: a hybrid between Cattleya warscewiczii Rchb.f.
1854 and Cattleya aurea Linden 1883 can be called Cattleya × hardyana Sander 1883 or Cattleya hardyana. An offspring of a Cattleya × hardyana pollenized by another Cattleya × hardyana would be called Cattleya × hardyana. Cattleya × hardyana would be the name of an offspring of a Cattleya × hardyana pollenized by either a Cattleya warscewiczii or a Cattleya aurea, or an offspring of either a Cattleya warscewiczii or a Cattleya aurea pollenized by a Cattleya × hardyana. × Brassocattleya is a nothogenus including all hybrids between Cattleya. It includes the species Brassocattleya × arauji known as Brassocattleya arauji, which includes all hybrids between Brassavola tuberculata and Cattleya forbesii. An earlier term was nothomorph for subordinate taxa to nothospecies. Since the 1982 meeting of the International Botanical Congress, such subordinate taxa are considered varieties; because many interspecific barriers to hybridization in the Orchidaceae are maintained in nature only by pollinator behavior, it is easy to produce complex interspecific and intergeneric hybrid orchid seeds: all it takes is a human motivated to use a toothpick, proper care of the mother plant as it develops a seed pod.
Germinating the seeds and growing them to maturity is more difficult, however. When a hybrid cross is made, all of the seedlings grown from the resulting seed pod are considered to be in the same grex. Any additional plants produced from the hybridization of the same two parents belong to the grex. Reciprocal crosses are included within the same grex. If two members of the same grex produce offspring, the offspring receive the same grex name as the parents. If a parent of a grex becomes a synonym, any grex names that were established by specifying the synonym are not discarded. All of the members of a specific grex may be loosely thought of as "sister plants", just like the brothers and sisters of any family, may share many traits or look quite different from one another; this is due to the randomization of genes passed on to progeny during sexual reproduction. The hybridizer who created a new grex chooses to register the grex with a registration authority, thus creating a new grex name, but there is no requirement to do this.
Individual plants may be given cultivar names to distinguish them from siblings in their grex. Cultivar names are given to superior plants with the expectation of propagating that plant; the rules for the naming of greges are defined by the International Code of Nomenclature for Cultivated Plants. The grex name differs from a species name in that the gregaric part of the name is capitalized, is not italicized, may consist of more than one word. Furthermore, names of greges are to be in a living language rather than Latin. For example: an artificially produced hybrid between Cattleya warscewiczii and C. dowiana is called C. Hardyana gx. An artificially produced seedling that results from pollinating a C. Hardyana gx with another C. Hardyana gx is a C. Hardyana gx. However, the hybrid produced between Cattleya Hardyana gx and C. dowiana is not C. Hardyana gx, but C. Prince John gx. In summary: C. Hardyana gx = C. warscewiczii × C. dowiana C. Eleanor gx = C. Hardyana gx × C. warscewiczii C. Prince John gx = C. dowiana × C.
Hardyana gx When the name of a grex is first established, a description is required that specifies two particular parents, where each parent is specified either as a species or as a grex. The grex name applies to all hybrids between those two parents. There is a permitted exception if the full name of one of the parents is known but the other is known only to genus level or nothogenus level. New grex names are now established by the Royal Horticultural Society, which receives applications from orchid hybridizers; the concept of grex and nothospecies are not equivalent. While greges are only used within the orchid family, nothospecies are used for any plant. Forthermore, a grex and nothospecie