Euphorbiaceae, the spurge family, is a large family of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants t ...

s. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as '' Euphorbia paralias'', are

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicina ...

s, but some, especially in the

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also refer ...

, are

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from tree ...

s or

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s, such as ''

Hevea brasiliensis ''Hevea brasiliensis'', the Pará rubber tree, ''sharinga'' tree, seringueira, or most commonly, rubber tree or rubber plant, is a flowering plant belonging to the spurge family Euphorbiaceae originally native to the Amazon basin, but is now pa ...

''. Some, such as ''

Euphorbia canariensis ''Euphorbia canariensis'', commonly known as the Canary Island spurge, Hercules club or in Spanish ''cardón'', is a succulent member of the genus ''Euphorbia'' and family Euphorbiaceae endemic to the Canary Islands. It is the plant symbol of ...

'', are

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 ...

and resemble

cacti A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Gree ...

because of

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

. This family has a cosmopolitan global distribution. The greatest diversity of species is in the tropics, however, the Euphorbiaceae also have many species in nontropical areas of all continents except

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...

Description

The

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

are alternate, seldom opposite, with stipules. They are mainly simple, but where compound, are always

palmate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular ...

, never

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, an ...

. Stipules may be reduced to

hair Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals. The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and fi ...

s, glands, or

spine Spine or spinal may refer to: Science Biology * Vertebral column, also known as the backbone * Dendritic spine, a small membranous protrusion from a neuron's dendrite * Thorns, spines, and prickles, needle-like structures in plants * Spine (zoolo ...

s, or in succulent species are sometimes absent. The plants can be

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy. Monoecy is ...

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproducti ...

. The radially symmetrical

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanis ...

s are unisexual, with the male and female flowers usually on the same plant. As can be expected from such a large family, a wide variety exists in the structure of the flowers. The

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the fila ...

s (the male organs) number from one to 10 (or even more). The female flowers are hypogynous, that is, with superior

ovaries The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...

. The genera in tribe Euphorbieae, subtribe Euphorbiinae ('' Euphorbia'' and close relatives) show a highly specialized form of

pseudanthium A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...

("false flower" made up of several true flowers) called a cyathium. This is usually a small, cup-like involucre consisting of fused-together bracts and peripheral nectary glands, surrounding a ring of male flowers, each a single stamen. In the middle of the cyathium stands a female flower, a single

pistil Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) '' pistils ...

with branched stigmas. This whole arrangement resembles a single flower. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...

is usually a schizocarp, but sometimes a

drupe In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part ( exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or ''pyrena'') of hardened endocarp with a seed (''kernel ...

. A typical schizocarp is the regma, a capsular fruit with three or more cells, each of which splits open explosively at maturity, scattering the small seeds. The family contains a large variety of phytotoxins (toxic substances produced by plants), including diterpene

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of simila ...

s, and cyanogenic glycosides (e.g. root tubers of

cassava ''Manihot esculenta'', commonly called cassava (), manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America. Although a perennial plant, cassava is extensively cultivated ...

). The seeds of the castor oil plant ''Ricinus communis'' contain the highly

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a sub ...

carbohydrate-binding protein

ricin Ricin ( ) is a lectin (a carbohydrate-binding protein) and a highly potent toxin produced in the seeds of the castor oil plant, ''Ricinus communis''. The median lethal dose (LD50) of ricin for mice is around 22 micrograms per kilogram of bo ...

. A milky

latex Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well. In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...

is a characteristic of the subfamilies

Euphorbioideae The Euphorbioideae are a subfamily within the family Euphorbiaceae. See also * Taxonomy of the Euphorbiaceae Here is a full taxonomy of the family Euphorbiaceae, according to the most recent molecular research. This complex family previousl ...

and

Crotonoideae The Crotonoideae (crotonoids) are a subfamily within the family Euphorbiaceae. See also * Taxonomy of the Euphorbiaceae Here is a full taxonomy of the family Euphorbiaceae, according to the most recent molecular research. This complex fam ...

, and the latex of the rubber tree ''

'' is the primary source of natural rubber. The latex is

poison Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...

ous in the Euphorbioideae, but innocuous in the Crotonoideae. White mangrove, also known as blind-your-eye mangrove latex ('' Excoecaria agallocha''), causes blistering on contact and temporary blindness if it contacts the eyes, hence its name. The latex of spurge was used as a

laxative 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 ...

. Recent molecular studies have shown that the enigmatic family

Rafflesiaceae The Rafflesiaceae are a family of rare parasitic plants comprising 36 species in 3 genera found in the tropical forests of east and southeast Asia, including ''Rafflesia arnoldii'', which has the largest flowers of all plants. The plants are en ...

, which was only recently recognized to belong to order Malpighiales, is derived from within the Euphorbiaceae. Euphorbiaceae are monoecious and open pollinated and so self-incompatibility is rare - although it has been reported in the past, apparently this was in error. It is confirmed to be absent or incomplete in

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition o ...

'' Chamaesyce'' by Ehrenfeld 1976, ''

Hevea ''Hevea'' is a genus of flowering plants in the spurge family, Euphorbiaceae, with about ten members. It is also one of many names used commercially for the wood of the most economically important rubber tree, '' H. brasiliensis''. The genus ...

'' by Bouharmont 1962, and '' Manihot'' by Jennings 1963 and George & Shifriss 1967. . .

Taxonomy

The family Euphorbiaceae is the fifth-largest flowering plant family and has about 7,500 species organised into 300 genera, 37 tribes, and three subfamilies; ''

Acalyphoideae The Acalyphoideae are a subfamily within the family Euphorbiaceae with 116 genera in 20 tribes. See also * Taxonomy of the Euphorbiaceae Here is a full taxonomy of the family Euphorbiaceae, according to the most recent molecular research. T ...

'', ''Crotonoideae'' and ''Euphorbioideae''. Amongst the oldest fossils of the group include the permineralised fruit '' Euphorbiotheca deccanensis'' from the

Intertrappean Beds The Intertrappean Beds are a Late Cretaceous geologic formation in India. The beds are found as interbeds between Deccan Traps layers. Indeterminate theropod and pterosaur remains have been recovered from the formation, as well as dinosaur eggs. ...

of India, dating to the late

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the inte ...

at the end of the Cretaceous, around 66 million years ago.

Uses and toxicity

Some species of Euphorbiaceae have economic significance, such as cassava (''Manihot esculenta''), castor oil plant (''Ricinus communis''), Barbados nut ('' Jatropha curcas''), and the Pará rubber tree (''Hevea brasiliensis''). Many are grown as

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that ...

s, such as poinsettia ('' Euphorbia pulcherrima'') or garden croton (''Codiaeum variegatum''). Leafy spurge (''

Euphorbia esula ''Euphorbia esula'', commonly known as green spurge or leafy spurge, is a species of spurge native to central and southern Europe (north to England, the Netherlands, and Germany), and eastward through most of Asia north of the Himalaya to Kor ...

'') and Chinese tallow (''Triadica sebifera'') are invasive weeds in North America. Seeds of the castor oil plant (''Ricinus communis'' L.) contain the extremely potent toxin, ricin. Although some species of the Euphorbiaceae have been used in

traditional medicine Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...

, , there is no rigorous clinical evidence that euphorbia extracts are effective for treating any disease. Numerous Euphorbiaceae species are listed on the poisonous plant database of the US

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

mainly because of the toxic sap.

Phytochemistry

Phytochemicals Phytochemicals are chemical compounds produced by plants, generally to help them resist fungi, bacteria and plant virus infections, and also consumption by insects and other animals. The name comes . Some phytochemicals have been used as pois ...

found in Euphorbiaceae species include diterpenoids, terpenoids,

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

s, alkaloids,

tannin Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids. The term ''tannin'' (from Anglo-Norman ''tanner'' ...

s, neriifolins (also found in

oleander ''Nerium oleander'' ( ), most commonly known as oleander or nerium, is a shrub or small tree cultivated worldwide in temperate and subtropical areas as an ornamental and landscaping plant. It is the only species currently classified in the ge ...

cycloartenol Cycloartenol is an important triterpenoid of the sterol class which is found in plants. It is the starting point for the synthesis of almost all plant steroids, making them chemically distinct from the steroids of fungi and animals, which are, ...

, lectin, and taraxerol, among others.

Conservation

Some species of this family are facing the risk of extinction. These include the ''Euphorbia'' species ''E. appariciana'', ''E. attastoma'', ''E. crossadenia'', and ''E. gymnoclada''.

References

External links

Marc Altenloh collection (photos)

International Euphorbia SocietyCactus and Succulent Society of AmericaData from GRIN Taxonomy
i
L. Watson and M.J. Dallwitz (1992 onwards). The families of flowering plants: descriptions, illustrations, identification, information retrieval.
https://web.archive.org/web/20070103200438/http://delta-intkey.com/ {{Authority control Malpighiales families