''Aloe'' (; also written ''Aloë'') is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

containing over 650

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

flowering Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

succulent In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

s.WFO (2022): Aloe L. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-4000001341. Accessed on: 06 Nov 2022 The most widely known species is ''

Aloe vera ''Aloe vera'' () is a succulent plant species of the genus ''Aloe''. It is widely distributed, and is considered an invasive species in many world regions. An evergreen perennial plant, perennial, it originates from the Arabian Peninsula, but ...

'', or "true aloe". It is called this because it is cultivated as the standard source for assorted pharmaceutical purposes. Other species, such as ''

Aloe ferox ''Aloe ferox'', commonly known as bitter aloe, is a species of flowering plant in the family Asphodelaceae. This woody aloe is indigenous to southern Africa. It is one of several ''Aloe'' species used to make bitter aloes, a purgative medication ...

'', are also cultivated or harvested from the wild for similar applications. The

APG IV system The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was publish ...

(2016) places the genus in the family

Asphodelaceae Asphodelaceae is a family of flowering plants in the order Asparagales. Such a family has been recognized by most taxonomists, but the circumscription has varied widely. In its current circumscription in the APG IV system, it includes about 4 ...

, subfamily

Asphodeloideae Asphodeloideae is a subfamily of the monocot family Asphodelaceae in the order Asparagales. It has previously been treated as a separate family, Asphodelaceae ''sensu stricto''. The family Asphodelaceae has now been proposed to be a nomen conser ...

. Within the subfamily it may be placed in the tribe

Aloeae Aloeae is a tribe of succulent plants in the subfamily Asphodeloideae of the family Asphodelaceae, consisting of the aloes and their close relatives. The taxon may also be treated as the subfamily Alooideae by those botanists who retain the narr ...

.Stevens, P.F. (2001 onwards).
Asphodelaceae
. ''Angiosperm Phylogeny Website''. Retrieved 2016-06-09. In the past, it has been assigned to the family

Aloaceae Asphodeloideae is a subfamily of the monocot family Asphodelaceae in the order Asparagales. It has previously been treated as a separate family, Asphodelaceae ''sensu stricto''. The family Asphodelaceae has now been proposed to be a nomen conser ...

(now included in the Asphodeloidae) or to a broadly

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

family

Liliaceae The lily family, Liliaceae, consists of about 15 genera and 610 species of flowering plants within the order Liliales. They are monocotyledonous, perennial, herbaceous, often bulbous geophytes. Plants in this family have evolved with a fai ...

(the lily family). The plant ''

Agave americana ''Agave americana'', commonly known as the century plant, maguey, or American aloe, is a flowering plant species belonging to the family Asparagaceae. It is native to Mexico and the United States, specifically Texas. This plant is widely cultiv ...

'', which is sometimes called "American aloe", belongs to the

Asparagaceae Asparagaceae (), known as the asparagus family, is a family of flowering plants, placed in the order Asparagales of the monocots. The family name is based on the edible garden asparagus, '' Asparagus officinalis''. This family includes both ...

, a different family. The genus is native to tropical and southern

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

Jordan Jordan, officially the Hashemite Kingdom of Jordan, is a country in the Southern Levant region of West Asia. Jordan is bordered by Syria to the north, Iraq to the east, Saudi Arabia to the south, and Israel and the occupied Palestinian ter ...

, the

Arabian Peninsula The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world. Geographically, the ...

, and various islands in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

(

Mauritius Mauritius, officially the Republic of Mauritius, is an island country in the Indian Ocean, about off the southeastern coast of East Africa, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Ag ...

Réunion Réunion (; ; ; known as before 1848) is an island in the Indian Ocean that is an overseas departments and regions of France, overseas department and region of France. Part of the Mascarene Islands, it is located approximately east of the isl ...

Comoros The Comoros, officially the Union of the Comoros, is an archipelagic country made up of three islands in Southeastern Africa, located at the northern end of the Mozambique Channel in the Indian Ocean. Its capital and largest city is Moroni, ...

, etc.). A few species have also become naturalized in other regions (

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

, etc.).

Etymology

The genus name ''Aloe'' is derived from the

Arabic Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...

word ''al'uluh'', meaning "bitter and shiny substance" or from

Hebrew Hebrew (; ''ʿÎbrit'') is a Northwest Semitic languages, Northwest Semitic language within the Afroasiatic languages, Afroasiatic language family. A regional dialect of the Canaanite languages, it was natively spoken by the Israelites and ...

''ahalim'', plural of ''ahal''.

Description

Most ''Aloe'' species have a

rosette Rosette is the French diminutive of ''rose''. It may refer to: Flower shaped designs * Rosette (award), a mark awarded by an organisation * Rosette (design), a small flower design *hence, various flower-shaped or rotational symmetric forms: ** R ...

of large, thick, fleshy

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

. ''Aloe''

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are tubular, frequently yellow, orange, pink, or red, and 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; other varieties may have a branched or unbranched

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

from which the fleshy leaves spring. They vary in color from grey to bright-green and are sometimes striped or

mottle Mottle is a pattern of irregular marks, spots, streaks, blotches or patches of different shades or colours. It is commonly used to describe the surface of plants or the skin of animals. In plants, mottling usually consists of yellowish spots on ...

d. Some aloes native to South Africa are tree-like (arborescent).

Systematics

The

(2016) places the genus in the family

, subfamily

. In the past it has also been assigned to the families

and Aloeaceae, as well as the family Asphodelaceae

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

, before this was merged into the Asphodelaceae

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

. The

circumscription Circumscription may refer to: * Circumscribed circle * Circumscription (logic) *Circumscription (taxonomy) * Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthr ...

of the genus has varied widely. Many genera, such as ''Lomatophyllum'', have been brought into

synonymy A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

. Species at one time placed in ''Aloe'', such as ''

'', have been moved to other genera. Molecular phylogenetic studies, particularly from 2010 onwards, suggested that as then circumscribed, ''Aloe'' was not

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

and should be divided into more tightly defined genera. In 2014,

John Charles Manning John Charles Manning (born 1962) is a South African botanist based in the Compton Herbarium, South African National Biodiversity Institute The South African National Biodiversity Institute (SANBI) is an organisation tasked with research an ...

and coworkers produced a phylogeny in which ''Aloe'' was divided into six genera: ''

Aloidendron ''Aloidendron'' is a genus of succulent plants in the subfamily Asphodeloideae. It was split off from the much larger genus ''Aloe'' in 2013. Taxonomy Phylogenetics, Phylogenetic studies indicated that several species that were traditionally ...

'', ''

Kumara Kumara may refer to: Places * Kumara (Mali), a province * Kumara, New Zealand, a town * Kumara (New Zealand electorate), a Parliamentary electorate Other uses * Kumara Illangasinghe, an Anglican bishop in Sri Lanka * Kumara (surname) * The Fo ...

'', ''

Aloiampelos ''Aloiampelos'' (combination of 'Aloe' and 'ampelos'=vine or creeper), formerly ''Aloe'' ser. ''Macrifoliae'' (the climbing-aloes) is a genus of succulent plants in the subfamily Asphodeloideae, comprising seven species found in Southern Africa. ...

'', ''Aloe'', ''

Aristaloe ''Aristaloe'' is a genus of evergreen flowering perennial plants in the family Asphodelaceae from Southern Africa. Its sole species is ''Aristaloe aristata'', known as guinea-fowl aloe or lace aloe. Naming and taxonomy This species is known loc ...

'' and ''

Gonialoe ''Gonialoe'' (the partridge aloes) is a small genus of three succulent plant species—''Gonialoe dinteri, Gonialoe sladeniana and Gonialoe variegata''—Endemism, endemic to coastal South Africa, Namibia and Angola. They were formerly included w ...

''.

Species

Over 600 species are accepted in the genus ''Aloe'', plus even more synonyms and unresolved species, subspecies, varieties, and hybrids. Some of the accepted species are: *'' Aloe aculeata'' Pole-Evans *''

Aloe africana ''Aloe africana'' (known as the Uitenhage aloe) is an arborescent (tree-like) species of aloe plant, indigenous to the Eastern Cape Province, South Africa. Description The plant grows slowly and flowers when it is four to five years old. Flow ...

'' Mill. *''

Aloe albida ''Aloe albida'' is a dwarf species of succulent plant. Characteristics Its flowers are small, white and borne on a single inflorescence. Its flowering time is usually in early autumn (March–April in the Southern Hemisphere), although it may be ...

'' (Stapf) Reynolds *''

Aloe albiflora ''Aloe albiflora'' is a species of aloe indigenous to Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the south ...

'' Guillaumin *''

Aloe arborescens ''Aloe arborescens'', the krantz aloe or candelabra aloe, is a species of flowering succulent perennial plant that belongs to the genus ''Aloe'', which it shares with the well known and studied ''Aloe vera''. The specific epithet ''arborescens'' ...

'' Mill. *'' Aloe arenicola'' Reynolds *'' Aloe argenticauda'' Merxm. & Giess *'' Aloe bakeri'' Scott-Elliot *''

Aloe ballii ''Aloe ballii'' is a species of plant in the family Asphodelaceae, subfamily Asphodeloideae. It is found in Mozambique and Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zi ...

'' Reynolds *'' Aloe ballyi'' Reynolds *'' Aloe brevifolia'' Mill. *''

Aloe broomii ''Aloe broomii'', known as the mountain aloe or snake aloe on account of its odd inflorescence, is a species of flowering plant in the genus ''Aloe'', found in southern Africa. Distribution This aloe is widespread in South Africa and Lesotho. In ...

'' Schönland *'' Aloe buettneri'' A.Berger *'' Aloe camperi'' Schweinf. *''

Aloe capitata ''Aloe capitata'' is a species of flowering plant in the Asphodelaceae family. It is native to Madagascar. References capitata Capitata is a suborder of Hydrozoa, a class of marine invertebrates belonging to the phylum Cnidaria. Charact ...

'' Baker *'' Aloe comosa'' Marloth & A.Berger *'' Aloe cooperi'' Baker *'' Aloe corallina'' Verd. *'' Aloe dewinteri'' Giess ex Borman & Hardy *'' Aloe erinacea'' D.S.Hardy *'' Aloe excelsa'' A.Berger *''

'' Mill. *''

Aloe forbesii ''Aloe forbesii'' is a small stemless ''Aloe'' native to Socotra, Yemen Yemen, officially the Republic of Yemen, is a country in West Asia. Located in South Arabia, southern Arabia, it borders Saudi Arabia to Saudi Arabia–Yemen border, th ...

'' Balf.f. *'' Aloe helenae'' Danguy *'' Aloe hereroensis'' Engl. *''

Aloe inermis ''Aloe inermis'' is a small, stemless Aloe native to Yemen. See also *Succulent plant In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climat ...

'' Forssk. *''

Aloe inyangensis ''Aloe inyangensis'' is a succulent aloe plant species, found only in the mountainous Eastern Highlands of Zimbabwe. It grows best in shady conditions but in some areas is also found in the open in heaths on mountain tops. There are two subspecie ...

'' Christian *''

Aloe jawiyon ''Aloe jawiyon'' is a species of succulent plant in the genus '' Aloe'' first described in 2004. It is endemic to the island of Socotra, Yemen, located in the Indian Ocean (near to the mouth of the Gulf of Aden), approximately 200 miles (321 km) ...

'' S.J.Christie, D.P.Hannon & Oakman ex A.G.Mill. *'' Aloe jucunda'' Reynolds *''

Aloe khamiesensis ''Aloe khamiesensis'' (also called Khamiesberg aloe or tweederly in Afrikaans) is a species of plant in the genus ''Aloe''. It is endemic to South Africa, where it occurs in the dry, western interior regions of Namaqualand and Bushmanland. It i ...

'' Pillans *'' Aloe kilifiensis'' Christian *'' Aloe maculata'' All. *''

Aloe marlothii ''Aloe marlothii'' (also known as the mountain aloe or the flat-flowered aloe) is a large, single-stemmed Southern African aloe of rocky places and open flat country, occasionally growing up to tall. Description Named after Rudolf Marloth, ...

'' A.Berger *''

Aloe mubendiensis ''Aloe mubendiensis'' is a species of ''Aloe'' native to west Uganda Uganda, officially the Republic of Uganda, is a landlocked country in East Africa. It is bordered to the east by Kenya, to the north by South Sudan, to the west by the ...

'' Christian *'' Aloe namibensis'' Giess *'' Aloe nyeriensis'' Christian & I.Verd. *'' Aloe pearsonii'' Schönland *'' Aloe peglerae'' Schönland *''

Aloe perfoliata ''Aloe perfoliata'', the rubble aloe or mitre aloe, is a hardy creeping aloe, found in rocky, mountainous areas throughout the Western Cape, South Africa. Naming and classification ''Aloe perfoliata'' was formerly known as ''Aloe mitriformis''. ...

'' L. *''

Aloe perryi ''Aloe perryi'' is a species of plant in the genus ''Aloe''. It is endemic to the island of Socotra in Yemen, and may be known by the common name, Socotrine aloe.''Western Arabia and the Red Sea'', Naval Intelligence Division, London 2005, p. 208 ...

'' Baker *''

Aloe petricola ''Aloe petricola'' belongs to the genus ''Aloe'' in the family Asphodelaceae, and is commonly known as a stone aloe. This particular aloe is a flowering species with unique and distinct inflorescences, which make the plant easy to identify and d ...

'' Pole-Evans *'' Aloe polyphylla'' Pillans *'' Aloe rauhii'' Reynolds *''

Aloe reynoldsii '' Aloe reynoldsii '' is a species of plant in the Asphodelaceae family. Description ''Aloe reynoldsii'' is a succulent without a stem or with very short stems, with leaves gathered in a rosette. The leaves are bluish-green, elongated, fleshy, ...

'' Letty *'' Aloe scobinifolia'' Reynolds & Bally *''

Aloe sinkatana ''Aloe sinkatana'' is a small, stemless Aloe native to Sudan. The plant is sometimes confused for the more common, medicinal ''Aloe vera''. See also *Succulent plant In botany, succulent plants, also known as succulents, are plants with parts ...

'' Reynolds *''

Aloe squarrosa ''Aloe squarrosa'' is a species of flowering plant in the Asphodelaceae family. It is from the island of Socotra, Yemen. Description ''Aloe squarrosa'' has smooth, green, spotted leaves that curve backwards. These recurved leaves are kept only ...

'' Baker ex Balf.f. *''

Aloe striata ''Aloe striata'', with the common name coral aloe, is a small, stemless South African Aloe species. Distribution This species occurs quite widely over the southern parts of the Cape Floristic Region, in the Eastern Cape Province and Western Cape ...

'' Haw. *''

Aloe succotrina ''Aloe succotrina'', the Fynbos aloe, is an aloe which is endemic to Cape Town and the south-western corner of the Western Cape, South Africa. Distribution ''Aloe succotrina'' is naturally found on the Cape Peninsula, and as far as Mossel Bay to ...

'' Lam. *'' Aloe suzannae'' Decary *'' Aloe thraskii'' Baker *''

'' (L.) Burm.f. *''

Aloe viridiflora ''Aloe viridiflora'' is a species of plant in the genus ''Aloe''. The species is endemic to Namibia with a wide range (the extent of occurrence is greater than 20,000 km2) and is known from at least six different populations. Current trends ...

'' Reynolds *''

Aloe wildii ''Aloe wildii'' is a species of aloe. Unlike many members of its genus, this species has linear leaves. It is native to a small area in south-east Africa and, like other succulent plants, it is resistant to drought. It bears attractive bright ora ...

'' (Reynolds) Reynolds 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 ''Gasteria'' is a genus of succulent plants, native to South Africa and the far south-west corner of Namibia. Naming The genus is named for its stomach-shaped flowers (''"gaster"'' is Greek for "stomach") that result from the swollen base on the ...

'' ( × ''Gasteraloe''), and between ''Aloe'' and ''

Astroloba ''Astroloba'' is a genus of flowering plants in the family (biology), family Asphodelaceae, subfamily Asphodeloideae,Stevens, P.F. (2001 onwards)"Asphodeloideae" ''Angiosperm Phylogeny Website'', retrieved 2016-06-10 native to the Cape Province ...

'' ('' ×Aloloba''). Aloe diversity

Uses

Aloe species are frequently cultivated as ornamental plants both in gardens and in pots. Many aloe species are highly decorative and are valued by collectors of succulents. ''Aloe vera'' is used both internally and externally on humans as

folk Folk or Folks may refer to: Sociology *Nation *People * Folklore ** Folk art ** Folk dance ** Folk hero ** Folk horror ** Folk music *** Folk metal *** Folk punk *** Folk rock ** Folk religion * Folk taxonomy Arts, entertainment, and media * Fo ...

alternative Alternative or alternate may refer to: Arts, entertainment and media * Alternative (Kamen Rider), Alternative (''Kamen Rider''), a character in the Japanese TV series ''Kamen Rider Ryuki'' * Alternative comics, or independent comics are an altern ...

medicine. The ''Aloe'' species is known for its medicinal and cosmetic properties. Around 75% of ''Aloe'' species are used locally for medicinal uses. The plants can also be made into types of special soaps or used in other skin care products (see

natural skin care Natural skin care uses topical creams and lotions made of ingredients available in nature. Much of the recent literature reviews plant-derived ingredients, which may include herbs, roots, flowers and essential oils, but natural substances in skin ...

). Numerous cultivars with mixed or uncertain parentage are grown. Of these, ''Aloe'' 'Lizard Lips' has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

. ''Aloe variegata'' has been planted on graves in the belief that this ensures eternal life.

Historical uses

Historical use of various aloe species is well documented. Documentation of the clinical effectiveness is available, although relatively limited. Of the 500+ species, only a few were used traditionally as

herbal medicine Herbal medicine (also called herbalism, phytomedicine or phytotherapy) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. Scientific evidence for the effectiveness of many herbal treatments ...

s, ''Aloe vera'' again being the most commonly used species. Also 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 Laxatives, purgatives, or aperients are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation. Laxatives vary as to how they work and the side effects they may have. Certain stimulant, lubri ...

. Unprocessed aloe that contains

aloin Aloin, also known as barbaloin, is a bitter, yellow-brown colored compound noted in the exudate of at least 68 ''Aloe'' species at levels from 0.1 to 6.6% of leaf dry weight (making between 3% and 35% of the total exudate), and in another 17 spec ...

is generally used as a laxative, whereas processed juice does not usually contain significant aloin. According to

Cancer Research UK Cancer Research UK (CRUK) is the world's largest independent cancer research organisation. It is registered as a charity in the United Kingdom and Isle of Man, and was formed on 4 February 2002 by the merger of The Cancer Research Campaign and t ...

, a potentially deadly product called T-UP is made of concentrated aloe, and promoted as a cancer cure. They say "there is currently no evidence that aloe products can help to prevent or treat cancer in humans".

Aloin in OTC laxative products

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 Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid pres ...

products. Most aloe juices today do not contain significant aloin.

Chemical properties

According to W. A. Shenstone, two classes of aloins are recognized: (1) nataloins, which yield picric and

oxalic acid Oxalic acid is an organic acid with the systematic name ethanedioic acid and chemical formula , also written as or or . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name i ...

s with

nitric acid Nitric acid is an inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but samples tend to acquire a yellow cast over time due to decomposition into nitrogen oxide, oxides of nitrogen. Most com ...

, and do not give a red coloration with nitric acid; and (2)

barbaloin Aloin, also known as barbaloin, is a bitter, yellow-brown colored compound noted in the exudate of at least 68 ''Aloe'' species at levels from 0.1 to 6.6% of leaf dry weight (making between 3% and 35% of the total exudate), and in another 17 spec ...

s, which yield aloetic acid (C₇H₂N₃O₅), chrysammic acid (C₇H₂N₂O₆), picric and oxalic acids with nitric acid, being reddened by the acid. This second group may be divided into a-barbaloins, obtained from Barbados ''Aloe'', and reddened in the cold, and 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 (2C₁₇H₁₃O₇·H₂O) forms bright-yellow scales, barbaloin (C₁₇H₁₈O₇)

prism PRISM is a code name for a program under which the United States National Security Agency (NSA) collects internet communications from various U.S. internet companies. The program is also known by the SIGAD . PRISM collects stored internet ...

atic crystals. ''Aloe'' species are used in essential oils as a safety measure to dilute the solution before they are applied to the skin.

Flavoring

''Aloe perryi'', ''A. barbadensis'', ''A. ferox'', and 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 Chartreuse () may refer to: Common meanings * Chartreuse (liqueur), a French liqueur * Chartreuse (color), a yellow-green color named after the liqueur * Grande Chartreuse, the original Carthusian monastery Other uses * Chartreuse (dish), a ...

.John Tellman (1900
''The Practical Hotel Steward''
The Hotel Monthly, Chicago

Gallery

File:Aloe vossii - plant (aka).jpg, '' Aloe vossii'' File:Aloe rubroviolacea2.jpg, '' A. rubroviolacea'' File:Aloe albiflora flowers.png, Not all aloes only have tublar flowers File:Aloe africana 1.jpg, ''

'' (Uitenhage aloe) File:Gardenology-IMG 5394 hunt10mar.jpg, ''

'' (flat-flowered aloe) File:Aloe pluridens (3).jpg, ''

Aloe pluridens ''Aloe pluridens'' (also known as the French Aloe) is an arborescent aloe indigenous to southern Africa. Description This species can occasionally grow up to 6 meters in height. It is usually single-stemmed (however in cultivation conditions ...

'' (French aloe) File:Aloe excelsa at Mount Coot-tha.JPG, '' Aloe excelsa'' (Zimbabwe aloe) File:Aloe rupestris, vroeë bloeiwyse, Pretoria.jpg, '' Aloe rupestris'' (bottlebrush aloe) File:Aloe speciosa - tilt head aloe.jpg, '' Aloe hexapetala'' (tilt-headed aloe) File:Blooming aloes wide view alternate, with bright sun behind.jpg, Blooming ''

'' File:Aloe cooperi in flower IMG 1702e.JPG, ''Aloe cooperi'' (''Aloe plicatilis'' in background on the right) File:Aloe hereroensis Auob C15.JPG, '' Aloe hereroensis'' File:Aloe molederana.jpg, Aloe molederana File:Aloe dijboutiensis whole plant.jpg, Aloe dijboutiensis File:Aloe peglerae01.jpg, '' Aloe peglerae'' File:Aloe saponaria 1.jpg, '' Aloe maculata'' - prev. ''A. saponaria'' (soap aloe) File:Aloe reitzii flowers.jpg, '' Aloe reitzii'' File:Aloe arborescens leaf cross section.jpg, Aloe arborescens leaf cross section File:Aloe karasbergensis young plant.jpg, Aloe karasbergensis - Plant 2023-0010-3

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