A greenhouse is a structure with walls and roof made chiefly of transparent material, such as glass, in which plants requiring regulated climatic conditions are grown. These structures range in size from small sheds to industrial-sized buildings. A miniature greenhouse is known as a cold frame; the interior of a greenhouse exposed to sunlight becomes warmer than the external ambient temperature, protecting its contents in cold weather. Many commercial glass greenhouses or hothouses are high tech production facilities for vegetables or flowers; the glass greenhouses are filled with equipment including screening installations, cooling and may be controlled by a computer to optimize conditions for plant growth. Different techniques are used to evaluate optimality-degrees and comfort ratio of greenhouse micro-climate in order to reduce production risk prior to cultivation of a specific crop; the idea of growing plants in environmentally controlled areas has existed since Roman times. The Roman emperor Tiberius ate a cucumber-like vegetable daily.
The Roman gardeners used artificial methods of growing to have it available for his table every day of the year. Cucumbers were planted in wheeled carts which were put in the sun daily taken inside to keep them warm at night; the cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as specularia or with sheets of selenite, according to the description by Pliny the Elder. The first description of a heated greenhouse is from the Sanga Yorok, a treatise on husbandry compiled by a royal physician of the Joseon dynasty of Korea during the 1450s, in its chapter on cultivating vegetables during winter; the treatise contains detailed instructions on constructing a greenhouse, capable of cultivating vegetables, forcing flowers, ripening fruit within an artificially heated environment, by utilizing ondol, the traditional Korean underfloor heating system, to maintain heat and humidity. The Annals of the Joseon Dynasty confirm that greenhouse-like structures incorporating ondol were constructed to provide heat for mandarin orange trees during the winter of 1438.
The concept of greenhouses appeared in the Netherlands and England in the 17th century, along with the plants. Some of these early attempts required enormous amounts of work to winterize. There were serious problems with providing balanced heat in these early greenhouses; the first'stove' greenhouse in the UK was completed at Chelsea Physic Garden by 1681. Today, the Netherlands has many of the largest greenhouses in the world, some of them so vast that they are able to produce millions of vegetables every year; the French botanist Charles Lucien Bonaparte is credited with building the first practical modern greenhouse in Leiden, during the 1800s to grow medicinal tropical plants. Only on the estates of the rich, the growth of the science of botany caused greenhouses to spread to the universities; the French called their first greenhouses orangeries, since they were used to protect orange trees from freezing. As pineapples became popular, pineries, or pineapple pits, were built. Experimentation with the design of greenhouses continued during the 17th century in Europe, as technology produced better glass and construction techniques improved.
The greenhouse at the Palace of Versailles was an example of their size and elaborateness. The golden era of the greenhouse was in England during the Victorian era, where the largest glasshouses yet conceived were constructed, as the wealthy upper class and aspiring botanists competed to build the most elaborate buildings. A good example of this trend is the pioneering Kew Gardens. Joseph Paxton, who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth, in Derbyshire, working for the Duke of Devonshire and built The Crystal Palace in London. Other large greenhouses built in the 19th century included the New York Crystal Palace, Munich’s Glaspalast and the Royal Greenhouses of Laeken for King Leopold II of Belgium. In Japan, the first greenhouse was built in 1880 by Samuel Cocking, a British merchant who exported herbs. In the 20th century, the geodesic dome was added to the many types of greenhouses. Notable examples are the Eden Project, in Cornwall, The Rodale Institute in Pennsylvania, the Climatron at the Missouri Botanical Garden in St. Louis and Toyota Motor Manufacturing Kentucky.
Greenhouse structures adapted in the 1960s when wider sheets of polyethylene film became available. Hoop houses were made by several companies and were frequently made by the growers themselves. Constructed of aluminum extrusions, special galvanized steel tubing, or just lengths of steel or PVC water pipe, construction costs were reduced; this resulted in many more greenhouses being constructed on garden centers. Polyethylene film durability increased when more effective UV-inhibitors were developed and added in the 1970s. Gutter-connected greenhouses became more prevalent in the 1990s; these greenhouses have
Euphorbia is a large and diverse genus of flowering plants called spurge, in the spurge family. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae, not just to members of the genus. Some euphorbias are commercially available, such as poinsettias at Christmas; some are cultivated as ornamentals, or collected and valued for the aesthetic appearance of their unique floral structures, such as the crown of thorns plant. Euphorbias from the deserts of Southern Africa and Madagascar have evolved physical characteristics and forms similar to cacti of North and South America, so they are incorrectly referred to as cacti; some are used as ornamentals in landscaping, because of beautiful or striking overall forms, drought and heat tolerance. Euphorbias range from tiny annual plants to long-lived trees; the genus has over or about 2,000 members, making it one of the largest genera of flowering plants. It has one of the largest ranges of chromosome counts, along with Rumex and Senecio.
Euphorbia antiquorum is the type species for the genus Euphorbia. It was first described by Carl Linnaeus in 1753 in Species Plantarum; the plants share the feature of having a poisonous, white, latex-like sap, unusual and unique floral structures. The genus may be described by properties of its members' gene sequences, or by the shape and form of its heads of flowers; when viewed as a whole, the head of flowers looks like a single flower. It has a unique kind of pseudanthium, called a cyathium, where each flower in the head is reduced to its barest essential part needed for sexual reproduction; the individual flowers are either male or female, with the male flowers reduced to only the stamen, the females to the pistil. These flowers have no sepals, petals, or other parts that are typical of flowers in other kinds of plants. Structures supporting the flower head and beneath have evolved to attract pollinators with nectar, with shapes and colors that function the way petals and other flower parts do in other flowers.
It is the only genus of plants that has all three kinds of photosynthesis, CAM, C3, C4. The genus can be found all over the world; the forms range from annual plants lying to well-developed tall trees. In deserts in Madagascar and southern Africa, convergent evolution has led to cactus-like forms where the plants occupy the same ecological niche as cacti do in deserts of North and South America; the genus is found in the tropical and subtropical regions of Africa and the Americas, but in temperate zones worldwide. Succulent species originate from Africa, the Americas, Madagascar. A wide range of insular species can be found. Among laypeople, Euphorbia species are among the plant taxa most confused with cacti the stem succulents. Euphorbias secrete a sticky, milky-white fluid with latex. Individual flowers of euphorbias are tiny and nondescript, without petals and sepals, unlike cacti, which have fantastically showy flowers. Euphorbias from desert habitats with growth forms similar to cacti have thorns, which are different from the spines of cacti.
The common name "spurge" derives from the Middle English/Old French espurge, due to the use of the plant's sap as a purgative. The botanical name Euphorbia derives from Euphorbos, the Greek physician of king Juba II of Numidia, who married the daughter of Anthony and Cleopatra. Juba was a prolific writer including natural history. Euphorbos wrote. In 12 BC, Juba named this plant after his physician Euphorbos, as Augustus Caesar had dedicated a statue to the brother of Euphorbos, Antonius Musa, the personal physician of Augustus. In 1753, botanist and taxonomist Carl Linnaeus assigned the name Euphorbia to the entire genus in the physician's honor; the plants are annual, biennial or perennial herbs, woody shrubs, or trees with a caustic, poisonous milky latex. The roots are thick and fleshy or tuberous. Many species are less succulent, thorny, or unarmed; the main stem and also the side arms of the succulent species are thick and fleshy, 15–91 cm tall. The deciduous leaves may be opposite, alternate, or in whorls.
In succulent species, the leaves are small and short-lived. The stipules are small transformed into spines or glands, or missing. Like all members of the family Euphorbiaceae, spurges have unisexual flowers. In Euphorbia, flowers occur in a head, called the cyathium; each male or female flower in the cyathium head has only its essential sexual part, in males the stamen, in females the pistil. The flowers do not have sepals, petals, or nectar to attract pollinators, although other nonflower parts of the plant have an appearance and nectar glands with similar roles. Euphorbias are the only plants known to have this kind of flower head. Nectar glands and nectar that attract pollinators are held in the involucre, a cuplike part below and supporting the cyathium head; the involucre is above and supported by bract-like modified leaf structures called cyathophylls', or cyathial leaves
Bolinas is an unincorporated coastal community in Marin County, California. The census designated place is located on the California coast 13 miles northwest of San Francisco by air; the community is known for its reclusive residents. It is only accessible via unmarked roads. Bolinas sits at an elevation of 36 feet above sea level, it is bound on the northeast by Bolinas Lagoon and Kent Island and on the south by Bolinas Bay and Duxbury Point. According to the United States Census Bureau, the CDP has a total area of 5.8 square miles, all of it land. The GNIS has cited archaic alternate town-names, including "Ballenas", "Baulenas", "Baulings", "Bawlines". Bolinas' downtown is located on the eastern side of town along Wharf Road, which ends at Bolinas Lagoon; the downtown buildings were built between 1850 and 1920. Brighton Avenue connects downtown to the south-facing Brighton Beach. In the southeast corner of town is the Little Mesa; the Big Mesa known as the Gridded Mesa, lies to the west, with Agate Beach at its western end.
By air, Bolinas is just 10 miles west-southwest of San Rafael, 13 miles northwest of San Francisco. While located just 2 miles from State Route 1, the area is not accessible by car; the driving time from San Rafael is 52 minutes, it takes over an hour to drive to downtown San Francisco. Bolinas lies west of the San Andreas Fault, which runs the length of Bolinas Lagoon and continues northward through Olema Valley and Tomales Bay. Bolinas and the Point Reyes peninsula are on the Pacific Plate, moving north relative to Stinson Beach and the North American Plate at an average rate of about 1 inch per year. Point Reyes National Seashore borders Bolinas to the northwest. Duxbury Reef State Marine Conservation Area encompasses Bolinas' western shoreline. Prior to the European colonization of California, the Coast Miwok lived in the area calling the area "Bali-N."Bolinas and present-day Stinson Beach were once encompassed by Rancho Las Baulines, a Mexican land grant given by Governor Pío Pico to Gregorio Briones in 1846.
The first post office in the town of Bolinas opened in 1863. In 1927, a 300-acre former dairy farm on the Big Mesa was subdivided into a grid of streets and 5,336 lots measuring 20' by 100'. Many of these lots were sold for $69.50 by the San Francisco Bulletin as a subscription promotion. Portions of the mesa, including sections of Ocean Parkway, have since eroded into the sea. A few streets on the mesa are paved and maintained by the county, but many are unpaved, either maintained by adjoining property owners or unmaintained; the Big Mesa has no sewer system, houses on the mesa have individual septic systems. In 1967, the Bolinas Community Public Utility District was formed by the Marin County Board of Supervisors, it merged two local water districts, the Bolinas Beach Public Utility District which served the Big Mesa, the Bolinas Public Utility District which served the Downtown and Little Mesa, with the Marin County Sanitary District #3, formed in 1908 to provide sewer service in the downtown.
The BCPUD provides water service and solid waste pickup throughout Bolinas, sewer service to the Downtown and Little Mesa. Bolinas' beaches were hit hard by the 1971 San Francisco Bay oil spill, with the community coming together to clean the beach of crude oil. In November 1971, the Bolinas Community Public Utility District instituted a moratorium on new water permits, which halted the construction of new homes; the moratorium was based on the limited local water supply during the summer months and in drought years, serves to limit new development in Bolinas. In 1990, the BCPUD enacted a moratorium on new sewer connections, to address the limited capacity of the sewage collection system. Many lots on the Big Mesa, remain undeveloped. Bolinas and its reclusive reputation are featured in the 1981 novel Ecotopia Emerging by Ernest Callenbach. In November 2003, Bolinas voters adopted Measure G, an advisory ballot measure declaring Bolinas "A acknowledged nature-loving town"; the Bolinas Museum was founded in 1983.
Today, it contains five galleries featuring contemporary art, historical information, works from local artists. Today, it puts on events for locals and visitors alike. Wildflowers, a film starring Daryl Hannah, was filmed in Bolinas. 2010The 2010 United States Census reported that the Bolinas CDP had a population of 1,620. The population density was 278.0 people per square mile. The racial makeup of Bolinas was 1,406 White, 27 African American, 10 Native American, 17 Asian, 14 Pacific Islander, 64 from other races, 82 from two or more races. Hispanic or Latino of any race were 260 persons; the Census reported that 88.4 percent of the population lived in households and 11.6 percent lived in non-institutionalized group quarters. There were 698 households, out of which 144 had children under the age of 18 living in them, 259 were opposite-sex married couples living together, 54 had a female householder with no husband present, 32 had a male householder with no wife present. There were 49 unmarried opposite-sex partnerships, nine same-sex married couples or partnerships.
There were 280 households made up of individuals and 98 had someone living alone, 65 y
A botanical garden or botanic garden is a garden dedicated to the collection, cultivation and display of a wide range of plants labelled with their botanical names. It may contain specialist plant collections such as cacti and other succulent plants, herb gardens, plants from particular parts of the world, so on. Visitor services at a botanical garden might include tours, educational displays, art exhibitions, book rooms, open-air theatrical and musical performances, other entertainment. Botanical gardens are run by universities or other scientific research organizations, have associated herbaria and research programmes in plant taxonomy or some other aspect of botanical science. In principle, their role is to maintain documented collections of living plants for the purposes of scientific research, conservation and education, although this will depend on the resources available and the special interests pursued at each particular garden; the origin of modern botanical gardens is traced to the appointment of professors of botany to the medical faculties of universities in 16th century Renaissance Italy, which entailed the curation of a medicinal garden.
However, the objectives and audience of today’s botanic gardens more resembles that of the grandiose gardens of antiquity and the educational garden of Theophrastus in the Lyceum of ancient Athens. The early concern with medicinal plants changed in the 17th century to an interest in the new plant imports from explorations outside Europe as botany established its independence from medicine. In the 18th century, systems of nomenclature and classification were devised by botanists working in the herbaria and universities associated with the gardens, these systems being displayed in the gardens as educational "order beds". With the rapid rise of European imperialism in the late 18th century, botanic gardens were established in the tropics, economic botany became a focus with the hub at the Royal Botanic Gardens, near London. Over the years, botanical gardens, as cultural and scientific organisations, have responded to the interests of botany and horticulture. Nowadays, most botanical gardens display.
The role of major botanical gardens worldwide has been considered so broadly similar as to fall within textbook definitions. The following definition was produced by staff of the Liberty Hyde Bailey Hortorium of Cornell University in 1976, it covers in some detail the many functions and activities associated with botanical gardens: A botanical garden is a controlled and staffed institution for the maintenance of a living collection of plants under scientific management for purposes of education and research, together with such libraries, herbaria and museums as are essential to its particular undertakings. Each botanical garden develops its own special fields of interests depending on its personnel, extent, available funds, the terms of its charter, it may include greenhouses, test grounds, an herbarium, an arboretum, other departments. It maintains a scientific as well as a plant-growing staff, publication is one of its major modes of expression; this broad outline is expanded: The botanic garden may be an independent institution, a governmental operation, or affiliated to a college or university.
If a department of an educational institution, it may be related to a teaching program. In any case, it is not to be restricted or diverted by other demands, it is not a landscaped or ornamental garden, although it may be artistic, nor is it an experiment station or yet a park with labels on the plants. The essential element is the intention of the enterprise, the acquisition and dissemination of botanical knowledge. A contemporary botanic garden is a protected natural urban green area, where a managing organization creates landscaped gardens and holds documented collections of living plants and/or preserved plant accessions containing functional units of heredity of actual or potential value for purposes such as scientific research, public display, sustainable use and recreational activities, production of marketable plant-based products and services for improvement of human well-being; the "New Royal Horticultural Society Dictionary of Gardening" points out that among the various kinds of organisations now known as botanical gardens are many public gardens with little scientific activity, it cites a more abbreviated definition, published by the World Wildlife Fund and IUCN when launching the ’’Botanic Gardens Conservation Strategy’’ in 1989: "A botanic garden is a garden containing scientifically ordered and maintained collections of plants documented and labelled, open to the public for the purposes of recreation and research."
This has been further reduced by Botanic Gardens Conservation International to the following definition which "encompasses the spirit of a true botanic garden": "A botanic garden is an institution holding documented collections of living plants for the purposes of scientific research, conservation and education." Worldwide, there are now about 1800 botanical gardens and arboreta in about 150 countries of which about 550 are in Europe, 2
A flower garden or floral garden is any garden where flowers are grown and displayed. Because flowers bloom at varying times of the year, some plants are annual, dying each winter, the design of flower gardens can take into consideration maintaining a sequence of bloom and consistent color combinations through varying seasons. Besides organizing the flowers in bedding-out schemes limited to annual and perennial flower beds, careful design takes the labour time, the color pattern of the flowers into account; the labour time can be decreased by using techniques such as mulching. In flower meadows, grass growth can be moderated by planting parasitic plants such as Rhinanthus. Flower color is another important feature of both the herbaceous border and the mixed border that includes shrubs as well as herbaceous plants. Flower gardens are sometimes tied in function to other kinds of gardens, like knot gardens or herb gardens, many herbs having decorative function, some decorative flowers being edible.
A simpler alternative to the designed flower garden is the "wildflower" seed mix, with assortments of seeds which will create a bed that contains flowers of various blooming seasons, so that some portion of them should always be in bloom. The best mixtures include combinations of perennial and biennials, which may not bloom until the following year, annuals that are "self-seeding", so they will return, creating a permanent flowerbed. Another more recent trend is the "flower garden in a box", where the entire design of a flower garden is pre-packaged, with separate packets of each kind of flower, a careful layout to be followed to create the proposed pattern of color in the garden-to-be. Many, if not most, plants considered decorative flowers originated as weeds, which if attractive enough would sometimes be tolerated by farmers because of their appeal; this led to an artificial selection process. This is thought to have occurred for the entire history of agriculture even earlier, when people tended to favor occurring food-gathering spots.
This may explain why many flowers function as companion plants to more useful agricultural plants. Once domesticated, most flowers were grown either separately or as part of gardens having some other primary function. In the West, the idea of gardens dedicated to flowers did not become common until the 19th century, though in fact many modern gardens are indeed flower gardens. Flower gardens are, indeed, a key factor in modern landscape design and architecture for large businesses, some of which pay to have large flower gardens torn out and replaced each season, in order to keep the color patterns consistent. A functional garden used to grow flowers for indoor use rather than outdoor display is known as a cutting garden, it is only a feature of large residences. The cutting garden is placed in a fertile and sunlight position out of public view and is not artistically arranged, as it contains flowers for cutting; the cutting garden may comprise a herb garden and ornamental vegetables as well. Raised-bed gardening Bedding Herbaceous border National Garden Bureau National Gardening Association Winnipeg In Bloom Documentary produced by Prairie Public Television
Marin County, California
Marin County is a county located in the San Francisco Bay Area of the U. S. state of California. As of the 2010 census, the population was 252,409, its county seat is San Rafael. Marin County is included in the San Francisco-Oakland-Hayward, CA Metropolitan Statistical Area across the Golden Gate Bridge from San Francisco; as of 2010, Marin County had the fifth highest income per capita in the United States at $91,483. The county is governed by the Marin County Board of Supervisors; the county is well known for its natural environment and liberal politics. San Quentin State Prison is located in the county. Autodesk, the publisher of AutoCAD, is located there, as well as numerous other high-tech companies; the Marin County Civic Center was designed by Frank Lloyd Wright and draws thousands of visitors a year to guided tours of its arch and atrium design. In 1994, a new county jail facility was embedded into the hillside nearby. Marin County's natural sites include the Muir Woods redwood forest, the Marin Headlands, Stinson Beach, the Point Reyes National Seashore, Mount Tamalpais.
The United States' oldest cross country running event, the Dipsea Race, takes place annually in Marin County, attracting thousands of athletes. Mountain biking was invented on the slopes of Mount Tamalpais in Marin. Marin County is one of the original 27 counties of California, created February 18, 1850, following adoption of the California Constitution of 1849 and just months before the state was admitted to the Union. According to General Mariano Vallejo, who headed an 1850 committee to name California's counties, the county was named for "Marin", great chief of the tribe Licatiut". Marin had been named Huicmuse until he was baptized as "Marino" at about age 20. Marin / Marino was born into the Huimen people, a Coast Miwok tribe of Native Americans who inhabited the San Rafael area. Vallejo believed. Marino did reside at Mission Dolores much of the time from his 1801 baptism and marriage until 1817 serving as a baptism witness and godfather. Starting in 1817, he served as an alcalde at the San Rafael Mission, where he lived from 1817 off and on until his death.
In 1821, Marino served as an expedition guide for the Spanish for a couple of years before escaping and hiding out for some months in the tiny Marin Islands. Another version of the origin of the county name is that the bay between San Pedro Point and San Quentin Point was named Bahía de Nuestra Señora del Rosario la Marinera in 1775, that Marin is an abbreviation of this name; the Coast Miwok Indians were hunters and gatherers whose ancestors had occupied the area for thousands of years. About 600 village sites have been identified in the county; the Coast Miwok numbered in the thousands. Today, there are few left and fewer with any knowledge of their Coast Miwok lineage. Efforts are being made. Francis Drake and the crew of the Golden Hind was thought to have landed on the Marin coast in 1579 claiming the land as Nova Albion. A bronze plaque inscribed with Drake's claim to the new lands, fitting the description in Drake's own account, was discovered in 1933; this so-called Drake's Plate of Brass was revealed as a hoax in 2003.
In 1595, Sebastian Cermeno lost the San Agustin, while exploring the Marin Coast. The Spanish explorer Vizcaíno landed about twenty years after Drake in what is now called Drakes Bay; however the first Spanish settlement in Marin was not established until 1817 when Mission San Rafael Arcángel was founded in response to the Russian-built Fort Ross to the north in what is now Sonoma County. Mission San Rafael Arcángel was founded in what is now downtown San Rafael as the 20th Spanish mission in the colonial Mexican province of Alta California by four priests, Father Narciso Duran from Mission San Jose, Father Abella from Mission San Francisco de Asís, Father Gil y Taboada and Father Mariano Payeras, the President of the Missions, on December 14, 1817, four years before Mexico gained independence from Spain. According to the U. S. Census Bureau, the county has a total area of 828 square miles, of which 520 square miles is land and 308 square miles is water, it is the fourth-smallest county in California by land area.
According to the records at the County Assessor-Recorder's Office, as of June 2006, Marin had 91,065 acres of taxable land, consisting of 79,086 parcels with a total tax basis of $39.8 billion. These parcels are divided into the following classifications: Geographically, the county forms a large, southward-facing peninsula, with the Pacific Ocean to the west, San Pablo Bay, San Francisco Bay to the east, – across the Golden Gate – the city of San Francisco to the south. Marin County's northern border is with Sonoma County. Most of the county's population resides on the eastern side, with a string of communities running along San Francisco Bay, from Sausalito to Tiburon to Corte Madera to San Rafael; the interior contains large areas of open space. West Marin has beaches which are popular destinations for tourists year-round. Notable features of the shoreline along the San Francisco Bay include the Sausalito shoreline, Richardson Bay, t
Aloe written Aloë, is a genus containing over 500 species of flowering succulent plants. The most known species is Aloe vera, or "true aloe", so called because it is cultivated as the standard source of so-called "aloe vera" for assorted pharmaceutical purposes. Other species, such as Aloe ferox are cultivated or harvested from the wild for similar applications; the APG IV system places the genus in the family Asphodelaceae, subfamily Asphodeloideae. Within the subfamily it may be placed in the tribe Aloeae. In the past, it has been assigned to the family Aloaceae or to a broadly circumscribed family Liliaceae; the plant Agave americana, sometimes called "American aloe", belongs to the Asparagaceae, a different family. The genus is native to tropical and southern Africa, Jordan, the Arabian Peninsula, various islands in the Indian Ocean. A few species have become naturalized in other regions. Most Aloe species have a rosette of large, fleshy leaves. Aloe flowers are tubular yellow, pink, or red, are borne, densely clustered and pendant, at the apex of simple or branched, leafless stems.
Many species of Aloe appear to be stemless, with the rosette growing directly at ground level. They are sometimes striped or mottled; some aloes native to South Africa are tree-like. The APG IV system places the genus in the family Asphodelaceae, subfamily Asphodeloideae. In the past it has been assigned to the families Liliaceae and Aloeaceae, as well as the family Asphodelaceae sensu stricto, before this was merged into the Asphodelaceae sensu lato; the circumscription of the genus has varied widely. Many genera, such as Lomatophyllum, have been brought into synonymy. Species at one time placed in Aloe, such as Agave americana, have been moved to other genera. Molecular phylogenetic studies from 2010 onwards, suggested that as circumscribed, Aloe was not monophyletic and should be divided into more defined genera. In 2014, John Charles Manning and coworkers produced a phylogeny in which Aloe was divided into six genera: Aloidendron, Aloiampelos, Aloe and Gonialoe. Over 500 species are accepted in the genus Aloe, plus more synonyms and unresolved species, subspecies and hybrids.
Some of the accepted species are: In addition to the species and hybrids between species within the genus, several hybrids with other genera have been created in cultivation, such as between Aloe and Gasteria, between Aloe and Astroloba. Aloe species are cultivated as ornamental plants both in gardens and in pots. Many aloe species are decorative and are valued by collectors of succulents. Aloe vera is used both internally and externally on humans as alternative medicine; the plants can be made into types of special soaps or used in other skin care products. Numerous cultivars with mixed or uncertain parentage are grown. Of these, Aloe ‘Lizard Lips’ has gained the Royal Horticultural Society’s Award of Garden Merit. Historical use of various aloe species is well documented. Documentation of the clinical effectiveness is available, although limited. Of the 500+ species, only a few were used traditionally as herbal medicines, Aloe vera again being the most used species. Included are A. perryi and A. ferox.
The Ancient Greeks and Romans used Aloe vera to treat wounds. In the Middle Ages, the yellowish liquid found inside the leaves was favored as a purgative. Unprocessed aloe that contains aloin is used as a laxative, whereas processed juice does not contain significant aloin; some species Aloe vera, are used in alternative medicine and first aid. Both the translucent inner pulp and the resinous yellow aloin from wounding the aloe plant are used externally for skin discomforts; as an herbal medicine, Aloe vera juice is used internally for digestive discomfort. According to Cancer Research UK, a deadly product called T-UP is made of concentrated aloe, promoted as a cancer cure, they say "there is no evidence that aloe products can help to prevent or treat cancer in humans". On May 9, 2002, the US Food and Drug Administration issued a final rule banning the use of aloin, the yellow sap of the aloe plant, for use as a laxative ingredient in over-the-counter drug products. Most aloe juices today do not contain significant aloin.
According to W. A. Shenstone, two classes of aloins are recognized: nataloins, which yield picric and oxalic acids with nitric acid, do not give a red coloration with nitric acid; this second group may be divided into a-barbaloins, obtained from Barbados Aloe, reddened in the cold, b-barbaloins, obtained from Aloe Socotrina and Zanzibar Aloe, reddened by ordinary nitric acid only when warmed or by fuming acid in the cold. Nataloin forms bright-yellow scales, barbaloin prismatic crystals. Aloe species contain a trace of volatile oil, to which their odour is due. Aloe perryi, A. barbadensis, A. ferox, hybrids of this species with A. africana and A. spicata are listed as natural flavoring substances in the US government Electronic Code of Federal Regulations. Aloe socotrina is said to be used in yellow Chartreuse. Aloe rubrolutea occurs as a charge in heraldry