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Orchids are plants that belong to the
family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Orchidaceae (), a diverse and widespread group 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 th ...
s with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering plants. The Orchidaceae have about 28,000 currently accepted
species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
, distributed in about 763 genera. (See ''External links'' below). The determination of which family is larger is still under debate, because verified data on the members of such enormous families are continually in flux. Regardless, the number of orchid species is nearly equal to the number of bony fishes, more than twice the number of
bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
species, and about four times the number of mammal species. The family encompasses about 6–11% of all species of seed plants. The largest genera are ''
Bulbophyllum ''Bulbophyllum'' is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is the largest genus in the orchid family and one of the largest genera of flowering plants with more than 2,000 species, exceeded in number o ...
'' (2,000 species), ''
Epidendrum ''Epidendrum'' , abbreviated Epi in the horticultural trade, is a large neotropical genus of the orchid family. With more than 1,500 species, some authors describe it as a mega-genus. The genus name (from Greek ''επί, epi'' and ''δένδρο ...
'' (1,500 species), ''
Dendrobium ''Dendrobium'' is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is a very large genus, containing more than 1,800 species that are found in diverse habitats throughout much of south, east and southeast Asi ...
'' (1,400 species) and ''
Pleurothallis ''Pleurothallis'' is a genus of orchids commonly called bonnet orchids. The genus name is derived from the Greek word , meaning "riblike branches". This refers to the rib-like stems of many species. The genus is often abbreviated as "Pths" in hor ...
'' (1,000 species). It also includes '' Vanilla'' (the genus of the vanilla plant), the type genus ''
Orchis ''Orchis'' is a genus in the orchid family (Orchidaceae), occurring mainly in Europe and Northwest Africa, and ranging as far as Tibet, Mongolia, and Xinjiang. The name is from the Ancient Greek ὄρχις ''orchis'', meaning "testicle", from ...
'', and many commonly cultivated plants such as ''
Phalaenopsis ''Phalaenopsis'' (), also known as moth orchids, is a genus of about seventy species of plants in the family Orchidaceae. Orchids in this genus are monopodial epiphytes or lithophytes with long, coarse roots, short, leafy stems and long-lasti ...
'' and ''
Cattleya ''Cattleya'' () is a genus of orchids from Costa Rica south to Argentina. The genus is abbreviated C in trade journals. Description Epiphytic or terrestrial orchids with cylindrical rhizome from which the fleshy noodle-like roots grow. Ps ...
''. Moreover, since the introduction of tropical species into cultivation in the 19th century, horticulturists have produced more than 100,000 hybrids and
cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...
s.


Description

Orchids are easily distinguished from other plants, as they share some very evident derived characteristics or synapomorphies. Among these are: bilateral symmetry of the flower ( zygomorphism), many resupinate flowers, a nearly always highly modified petal (labellum), fused stamens and
carpel 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' ...
s, and extremely small
seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s.


Stem and roots

All orchids are
perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wid ...
herbs that lack any permanent woody structure. They can grow according to two patterns: * Monopodial: The stem grows from a single bud, leaves are added from the apex each year, and the stem grows longer accordingly. The stem of orchids with a monopodial growth can reach several metres in length, as in ''
Vanda ''Vanda'', abbreviated in the horticultural trade as ''V.,'' is a genus in the orchid family, Orchidaceae. There are about 87 species, and the genus is commonly cultivated for the marketplace. This genus and its allies are considered to be among ...
'' and '' Vanilla''. *
Sympodial Sympodial growth is a bifurcating branching pattern where one branch develops more strongly than the other, resulting in the stronger branches forming the primary shoot and the weaker branches appearing laterally. A sympodium, also referred to a ...
: Sympodial orchids have a front (the newest growth) and a back (the oldest growth). The plant produces a series of adjacent shoots, which grow to a certain size, bloom and then stop growing and are replaced. Sympodial orchids grow horizontally, rather than vertically, following the surface of their support. The growth continues by development of new leads, with their own leaves and roots, sprouting from or next to those of the previous year, as in ''
Cattleya ''Cattleya'' () is a genus of orchids from Costa Rica south to Argentina. The genus is abbreviated C in trade journals. Description Epiphytic or terrestrial orchids with cylindrical rhizome from which the fleshy noodle-like roots grow. Ps ...
''. While a new lead is developing, the rhizome may start its growth again from a so-called 'eye', an undeveloped bud, thereby branching. Sympodial orchids may have visible
pseudobulb The pseudobulb is a storage organ found in many epiphytic and terrestrial sympodial orchids. It is derived from a thickening of the part of a stem between leaf nodes and may be composed of just one internode or several, termed heteroblastic and ...
s joined by a '' rhizome'', which creeps along the top or just beneath the soil. Terrestrial orchids may be
rhizomatous In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow ho ...
or form corms or tubers. The root caps of terrestrial orchids are smooth and white. Some sympodial terrestrial orchids, such as ''
Orchis ''Orchis'' is a genus in the orchid family (Orchidaceae), occurring mainly in Europe and Northwest Africa, and ranging as far as Tibet, Mongolia, and Xinjiang. The name is from the Ancient Greek ὄρχις ''orchis'', meaning "testicle", from ...
'' and '' Ophrys'', have two subterranean tuberous roots. One is used as a food reserve for wintry periods, and provides for the development of the other one, from which visible growth develops. In warm and constantly humid climates, many terrestrial orchids do not need pseudobulbs. Epiphytic orchids, those that grow upon a support, have modified
aerial root Aerial roots are roots above the ground. They are almost always adventitious. They are found in diverse plant species, including epiphytes such as orchids (''Orchidaceae''), tropical coastal swamp trees such as mangroves, banyan figs (''Fic ...
s that can sometimes be a few meters long. In the older parts of the roots, a modified spongy epidermis, called a
velamen Velamen or velamen radicum is a spongy, multiple epidermis that covers the roots of some epiphytic or semi-epiphytic plants, such as orchid and '' Clivia'' species. The velamen of an orchid is the white or gray covering of aerial roots (when dry ...
, has the function of absorbing humidity. It is made of dead cells and can have a silvery-grey, white or brown appearance. In some orchids, the velamen includes spongy and fibrous bodies near the passage cells, called tilosomes. The cells of the root epidermis grow at a right angle to the axis of the root to allow them to get a firm grasp on their support. Nutrients for epiphytic orchids mainly come from mineral dust, organic detritus, animal droppings and other substances collecting among on their supporting surfaces. The base of the stem of sympodial epiphytes, or in some species essentially the entire stem, may be thickened to form a
pseudobulb The pseudobulb is a storage organ found in many epiphytic and terrestrial sympodial orchids. It is derived from a thickening of the part of a stem between leaf nodes and may be composed of just one internode or several, termed heteroblastic and ...
that contains nutrients and water for drier periods. The pseudobulb has a smooth surface with lengthwise grooves, and can have different shapes, often conical or oblong. Its size is very variable; in some small species of ''
Bulbophyllum ''Bulbophyllum'' is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is the largest genus in the orchid family and one of the largest genera of flowering plants with more than 2,000 species, exceeded in number o ...
'', it is no longer than two millimeters, while in the largest orchid in the world, ''
Grammatophyllum speciosum ''Grammatophyllum speciosum'', also called giant orchid, tiger orchid, sugar cane orchid or queen of the orchids, is a species of orchid native to Laos, Myanmar, Thailand, Vietnam, Borneo, Indonesia (Sumatra, Java, Sulawesi) and Malaysia. It has ...
'' (giant orchid), it can reach three meters. Some ''
Dendrobium ''Dendrobium'' is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is a very large genus, containing more than 1,800 species that are found in diverse habitats throughout much of south, east and southeast Asi ...
'' species have long, canelike pseudobulbs with short, rounded leaves over the whole length; some other orchids have hidden or extremely small pseudobulbs, completely included inside the leaves. With ageing the pseudobulb sheds its leaves and becomes dormant. At this stage it is often called a backbulb. Backbulbs still hold nutrition for the plant, but then a pseudobulb usually takes over, exploiting the last reserves accumulated in the backbulb, which eventually dies off, too. A pseudobulb typically lives for about five years. Orchids without noticeable pseudobulbs are also said to have growths, an individual component of a sympodial plant.


Leaves

Like most monocots, orchids generally have simple leaves with parallel veins, although some
Vanilloideae Vanilloideae is one of the subfamilies of orchids belonging to the large family Orchidaceae. Lindley (1836) and Garay (1986)Garay,L. (1986), Olim Vanillaceae. Botanical Museum Leaflets. Harvard University 30 : 233-237. treated it as a separate f ...
have reticulate
venation Venation may refer to: * Venation (botany), the arrangement of veins in leaves * Wing venation, the arrangement of veins in insect wings See also * * Vernation Vernation (from ''vernal'' meaning ''spring'', since that is when leaves spring fort ...
. Leaves may be ovate, lanceolate, or orbiculate, and very variable in size on the individual plant. Their characteristics are often diagnostic. They are normally alternate on the stem, often folded lengthwise along the centre ("plicate"), and have no
stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...
s. Orchid leaves often have
siliceous Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
bodies called stegmata in the vascular bundle sheaths (not present in the
Orchidoideae The Orchidoideae, or the orchidoid orchids, are a subfamily of the orchid family (Orchidaceae) that contains around 3630 species. Species typically have a single ( monandrous), fertile anther which is erect and basitonic. Description The subf ...
) and are fibrous. The structure of the leaves corresponds to the specific habitat of the plant. Species that typically bask in sunlight, or grow on sites which can be occasionally very dry, have thick, leathery leaves and the laminae are covered by a waxy cuticle to retain their necessary water supply. Shade-loving species, on the other hand, have long, thin leaves. The leaves of most orchids are perennial, that is, they live for several years, while others, especially those with plicate leaves as in ''
Catasetum ''Catasetum'', abbreviated as Ctsm. in horticultural trade, is a genus of showy epiphytic Orchids, family Orchidaceae, subfamily Epidendroideae, tribe Cymbidieae, subtribe Catasetinae, with 166 species, many of which are highly prized in hortic ...
'', shed them annually and develop new leaves together with new pseudobulbs. The leaves of some orchids are considered ornamental. The leaves of '' Macodes sanderiana'', a semiterrestrial or rock-hugging (" lithophyte") orchid, show a sparkling silver and gold veining on a light green background. The cordate leaves of ''Psychopsis limminghei'' are light brownish-green with maroon-puce markings, created by flower pigments. The attractive mottle of the leaves of
lady's slipper Cypripedioideae is a subfamily of orchids commonly known as lady's slipper orchids, lady slipper orchids or slipper orchids. Cypripedioideae includes the genera '' Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium'' and ''Selenipedium''. T ...
s from tropical and subtropical Asia (''
Paphiopedilum ''Paphiopedilum'', often called the Venus slipper, is a genus of the lady slipper orchid subfamily '' Cypripedioideae'' of the flowering plant family Orchidaceae. The genus comprises some 80 accepted taxa including several natural hybrids. The ...
''), is caused by uneven distribution of chlorophyll. Also, '' Phalaenopsis schilleriana'' is a pastel pink orchid with leaves spotted dark green and light green. The jewel orchid (''Ludisia discolor'') is grown more for its colorful leaves than its white flowers. Some orchids, such as ''
Dendrophylax lindenii ''Dendrophylax lindenii'', the ghost orchid (a common name also used for ''Epipogium aphyllum'') is a perennial epiphyte from the orchid family (Orchidaceae). It is native to Florida, the Bahamas, and Cuba. Other common names include palm polly ...
'' (ghost orchid), '' Aphyllorchis'' and ''
Taeniophyllum ''Taeniophyllum'', commonly known as ribbon roots or 带叶兰属 (dai ye lan shu) is a genus of about 240 species of epiphytic or lithophytic plants from the orchid family, Orchidaceae. Plants in this genus are more or less leafless with a ver ...
'' depend on their green roots for photosynthesis and lack normally developed leaves, as do all of the
heterotrophic A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...
species. Orchids of the genus '' Corallorhiza'' (coralroot orchids) lack leaves altogether and instead wrap their roots around the roots of mature trees and use specialized fungi to harvest sugars.


Flowers

Orchid flowers have three
sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...
s, three petals and a three-chambered ovary. The three sepals and two of the petals are often similar to each other but one petal is usually highly modified, forming a "lip" or labellum. In most orchid genera, as the flower develops, it undergoes a twisting through 180°, called resupination, so that the labellum lies below the column. The labellum functions to attract insects, and in resupinate flowers, also acts as a landing stage, or sometimes a trap. The reproductive parts of an orchid flower are unique in that the stamens and
style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...
are joined to form a single structure, the column. Instead of being released singly, thousands of pollen grains are contained in one or two bundles called
pollinia A pollinium (plural pollinia) is a coherent mass of pollen grains in a plant that are the product of only one anther, but are transferred, during pollination, as a single unit. This is regularly seen in plants such as orchids and many species of mil ...
that are attached to a sticky disc near the top of the column. Just below the pollinia is a second, larger sticky plate called the stigma.


Reproduction


Pollination

The complex mechanisms that orchids have evolved to achieve cross-pollination were investigated by
Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended ...
and described in ''
Fertilisation of Orchids ''Fertilisation of Orchids'' is a book by English naturalist Charles Darwin published on 15 May 1862 under the full explanatory title ''On the Various Contrivances by Which British and Foreign Orchids Are Fertilised by Insects, and On the Good ...
'' (1862). Orchids have developed highly specialized
pollination Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...
systems, thus the chances of being pollinated are often scarce, so orchid flowers usually remain receptive for very long periods, rendering unpollinated flowers long-lasting in cultivation. Most orchids deliver pollen in a single mass. Each time pollination succeeds, thousands of ovules can be fertilized. Pollinators are often visually attracted by the shape and colours of the labellum. However, some ''
Bulbophyllum ''Bulbophyllum'' is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is the largest genus in the orchid family and one of the largest genera of flowering plants with more than 2,000 species, exceeded in number o ...
'' species attract male fruit flies ('' Bactrocera'' and '' Zeugodacus'' spp.) solely via a floral chemical which simultaneously acts as a floral reward (e.g.
methyl eugenol Methyl eugenol (allylveratrol) is a natural chemical compound classified as a phenylpropene, a type of phenylpropanoid. It is the methyl ether of eugenol and is important to insect behavior and pollination. It is found in various essential oils. ...
, raspberry ketone, or
zingerone Zingerone, also called vanillylacetone, is a major flavor component of ginger, providing the sweet flavor of cooked ginger. Zingerone is a crystalline solid that is sparingly soluble in water and soluble in ether. Zingerone is similar in chemica ...
) to perform pollination. The flowers may produce attractive odours. Although absent in most species, nectar may be produced in a
spur A spur is a metal tool designed to be worn in pairs on the heels of riding boots for the purpose of directing a horse or other animal to move forward or laterally while riding. It is usually used to refine the riding aids (commands) and to ba ...
of the labellum (8 in the illustration above), or on the point of the sepals, or in the septa of the ovary, the most typical position amongst the
Asparagales Asparagales (asparagoid lilies) is an order of plants in modern classification systems such as the Angiosperm Phylogeny Group (APG) and the Angiosperm Phylogeny Web. The order takes its name from the type family Asparagaceae and is placed in t ...
. In orchids that produce pollinia, pollination happens as some variant of the following sequence: when the pollinator enters into the flower, it touches a viscidium, which promptly sticks to its body, generally on the head or abdomen. While leaving the flower, it pulls the pollinium out of the anther, as it is connected to the viscidium by the caudicle or stipe. The caudicle then bends and the pollinium is moved forwards and downwards. When the pollinator enters another flower of the same species, the pollinium has taken such position that it will stick to the stigma of the second flower, just below the rostellum, pollinating it. In horticulture, artificial orchid pollination is achieved by removing the pollinia with a small instrument such as a toothpick from the pollen parent and transferring them to the seed parent. Some orchids mainly or totally rely on
self-pollination Self-pollination is a form of pollination in which pollen from the same plant arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen is transferred ...
, especially in colder regions where pollinators are particularly rare. The caudicles may dry up if the flower has not been visited by any pollinator, and the pollinia then fall directly on the stigma. Otherwise, the anther may rotate and then enter the stigma cavity of the flower (as in '' Holcoglossum amesianum''). The slipper orchid ''
Paphiopedilum parishii ''Paphiopedilum parishii'' is a species of orchid found in northern and western Thailand, Laos, Myanmar, Yunnan and Assam, in montane forests at 1200–2200 m above sea level. It is named after Charles Samuel Pollock Parish, an English botanist ...
'' reproduces by
self-fertilization Autogamy, or self-fertilization, refers to the fusion of two gametes that come from one individual. Autogamy is predominantly observed in the form of self-pollination, a reproductive mechanism employed by many flowering plants. However, species ...
. This occurs when the anther changes from a solid to a liquid state and directly contacts the stigma surface without the aid of any pollinating agent or floral assembly. The labellum of the
Cypripedioideae Cypripedioideae is a subfamily of orchids commonly known as lady's slipper orchids, lady slipper orchids or slipper orchids. Cypripedioideae includes the genera ''Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium'' and ''Selenipedium''. The ...
is poke bonnet-shaped, and has the function of trapping visiting insects. The only exit leads to the anthers that deposit pollen on the visitor. In some extremely specialized orchids, such as the Eurasian genus '' Ophrys'', the labellum is adapted to have a colour, shape, and odour which attracts male insects via mimicry of a receptive female. Pollination happens as the insect attempts to mate with flowers. Many neotropical orchids are pollinated by male orchid bees, which visit the flowers to gather volatile chemicals they require to synthesize pheromonal attractants. Males of such species as '' Euglossa imperialis'' or ''
Eulaema meriana ''Eulaema meriana'' is a large-bodied bee species in the tribe Euglossini, otherwise known as the orchid bees. The species is a solitary bee and is native to tropical Central and South America. The male collects fragrances from orchid flowers, wh ...
'' have been observed to leave their territories periodically to forage for aromatic compounds, such as cineole, to synthesize pheromone for attracting and mating with females. Each type of orchid places the pollinia on a different body part of a different species of bee, so as to enforce proper cross-pollination. A rare
achlorophyllous Myco-heterotrophy (from Greek μύκης , "fungus", ἕτερος ', "another", "different" and τροφή ', "nutrition") is a symbiotic relationship between certain kinds of plants and fungi, in which the plant gets all or part of its food fro ...
saprophytic Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ( ...
orchid growing entirely underground in Australia, '' Rhizanthella slateri'', is never exposed to light, and depends on
ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...
s and other terrestrial insects to pollinate it. ''
Catasetum ''Catasetum'', abbreviated as Ctsm. in horticultural trade, is a genus of showy epiphytic Orchids, family Orchidaceae, subfamily Epidendroideae, tribe Cymbidieae, subtribe Catasetinae, with 166 species, many of which are highly prized in hortic ...
'', a genus discussed briefly by Darwin, actually launches its viscid pollinia with explosive force when an insect touches a
seta In biology, setae (singular seta ; from the Latin word for " bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. ...
, knocking the pollinator off the flower. After pollination, the sepals and petals fade and wilt, but they usually remain attached to the ovary. In 2011, '' Bulbophyllum nocturnum'' was discovered to flower nocturnally.


Asexual reproduction

Some species, such as in the genera ''Phalaenopsis'', ''Dendrobium'', and ''Vanda'', produce offshoots or plantlets formed from one of the nodes along the stem, through the accumulation of growth hormones at that point. These shoots are known as
keiki In horticulture, a keiki ( ) is a plant produced asexually by an orchid plant, especially ''Dendrobium'', ''Epidendrum'' (''sensu lato''), and ''Phalaenopsis'' orchids. The baby plant is an exact clone of the mother plant, sometimes flowering w ...
.


Fruits and seeds

The ovary typically develops into a capsule that is dehiscent by three or six longitudinal slits, while remaining closed at both ends. The
seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s are generally almost microscopic and very numerous, in some species over a million per capsule. After ripening, they blow off like dust particles or spores. Most orchid species lack endosperm in their seed and must enter symbiotic relationships with various
mycorrhizal   A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the pla ...
basidiomyceteous
fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
that provide them the necessary nutrients to germinate, so almost all orchid species are
mycoheterotrophic Myco-heterotrophy (from Greek μύκης , "fungus", ἕτερος ', "another", "different" and τροφή ', "nutrition") is a symbiotic relationship between certain kinds of plants and fungi, in which the plant gets all or part of its food fro ...
during germination and reliant upon fungi to complete their lifecycles. Only a handful of orchid species have seed that can germinate without mycorrhiza, namely the species within the genus ''Disa'' with hydrochorous seeds. As the chance for a seed to meet a suitable fungus is very small, only a minute fraction of all the seeds released grow into adult plants. In cultivation, germination typically takes weeks. Horticultural techniques have been devised for germinating orchid seeds on an artificial nutrient medium, eliminating the requirement of the
fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from t ...
for germination and greatly aiding the propagation of ornamental orchids. The usual medium for the sowing of orchids in artificial conditions is agar gel combined with a
carbohydrate In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or m ...
energy source. The carbohydrate source can be combinations of discrete sugars or can be derived from other sources such as banana,
pineapple The pineapple (''Ananas comosus'') is a tropical plant with an edible fruit; it is the most economically significant plant in the family Bromeliaceae. The pineapple is indigenous to South America, where it has been cultivated for many centuri ...
, peach, or even
tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...
puree or coconut water. After the preparation of the agar medium, it is poured into
test tubes Test(s), testing, or TEST may refer to: * Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities Arts and entertainment * ''Test'' (2013 film), an American film * ''Test'' (2014 film), ...
or jars which are then autoclaved (or cooked in a pressure cooker) to sterilize the medium. After cooking, the medium begins to gel as it cools.


Taxonomy

The taxonomy of this family is in constant flux, as new studies continue to clarify the relationships between species and groups of species, allowing more
taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
at several ranks to be recognized. The Orchidaceae is currently placed in the order
Asparagales Asparagales (asparagoid lilies) is an order of plants in modern classification systems such as the Angiosperm Phylogeny Group (APG) and the Angiosperm Phylogeny Web. The order takes its name from the type family Asparagaceae and is placed in t ...
by the APG III system of 2009. Five subfamilies are recognised. The
cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...
below was made according to the
APG system The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved A ...
of 1998. It represents the view that most botanists had held up to that time. It was supported by morphological studies, but never received strong support in molecular phylogenetic studies. In 2015, a
phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
study showed strong statistical support for the following
topology In mathematics, topology (from the Greek words , and ) is concerned with the properties of a geometric object that are preserved under continuous deformations, such as stretching, twisting, crumpling, and bending; that is, without closing ...
of the orchid
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 ...
, using 9 kb of plastid and nuclear DNA from 7
gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
s, a topology that was confirmed by a
phylogenomic Phylogenomics is the intersection of the fields of evolution and genomics. The term has been used in multiple ways to refer to analysis that involves genome data and evolutionary reconstructions. It is a group of techniques within the larger fields ...
study in the same year.


Evolution

A study in the scientific journal ''
Nature Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are ...
'' has hypothesised that the origin of orchids goes back much longer than originally expected. An extinct species of stingless bee, ''Proplebeia dominicana'', was found trapped in
Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
amber Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In ...
from about 15-20 million years ago. The bee was carrying pollen of a previously unknown orchid taxon, '' Meliorchis caribea'', on its wings. This find is the first evidence of fossilised orchids to date and shows insects were active pollinators of orchids then. This extinct orchid, ''M. caribea'', has been placed within the extant tribe
Cranichideae Cranichideae is an orchid tribe in the subfamily Orchidoideae. See also * Taxonomy of the Orchidaceae The taxonomy of the Orchidaceae (orchid family) has evolved slowly during the last 250 years, starting with Carl Linnaeus who in 1753 recogni ...
, subtribe
Goodyerinae Goodyerinae is an orchid subtribe in the tribe Cranichideae. Certain orchids in this subtribe are referred to as jewel orchids, for instance ''Ludisia'', '' Goodyera'', '' Dossinia'', and '' Anoectochilus''. Genera Genera accepted in Chase et ...
(subfamily
Orchidoideae The Orchidoideae, or the orchidoid orchids, are a subfamily of the orchid family (Orchidaceae) that contains around 3630 species. Species typically have a single ( monandrous), fertile anther which is erect and basitonic. Description The subf ...
). An even older orchid species, ''
Succinanthera baltica ''Succinanthera baltica'' is an extinct, middle Eocene orchid known only from an anther cap with pollinarium attached to the base of the leg of a female fungus gnat, ''Bradysia'', trapped in Baltic amber. It is the only species in the genus ''Su ...
'', was described from the
Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...
Baltic amber The Baltic region is home to the largest known deposit of amber, called Baltic amber or succinite. It was produced sometime during the Eocene epoch, but exactly when is controversial. It has been estimated that these forests created more than ...
by Poinar & Rasmussen (2017). Genetic sequencing indicates orchids may have arisen earlier, 76 to 84 million years ago during the
Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...
. According to Mark W. Chase ''et al.'' (2001), the overall biogeography and phylogenetic patterns of Orchidaceae show they are even older and may go back roughly 100 million years. Using the molecular clock method, it was possible to determine the age of the major branches of the orchid family. This also confirmed that the subfamily
Vanilloideae Vanilloideae is one of the subfamilies of orchids belonging to the large family Orchidaceae. Lindley (1836) and Garay (1986)Garay,L. (1986), Olim Vanillaceae. Botanical Museum Leaflets. Harvard University 30 : 233-237. treated it as a separate f ...
is a branch at the basal dichotomy of the
monandrous In botanical terms, monandrous simply means to have a single stamen. In orchids A distinction between monandrous and other flowers is particularly relevant in the classification of orchids. The monandrous orchids form a clade consisting of the s ...
orchids, and must have evolved very early in the evolution of the family. Since this subfamily occurs worldwide in tropical and subtropical regions, from tropical America to tropical Asia, New Guinea and West Africa, and the continents began to split about 100 million years ago, significant biotic exchange must have occurred after this split (since the age of ''Vanilla'' is estimated at 60 to 70 million years). Genome duplication occurred prior to the divergence of this taxon.


Genera

There are around 800 genera of orchids. The following are amongst the most notable genera of the orchid family: * '' Aa'' * '' Abdominea'' * '' Acampe'' * '' Acanthophippium'' * ''
Aceratorchis ''Galearis'' is a genus of the orchid family (Orchidaceae) native to North America and eastern Asia. It contains about ten recognized species. The family name comes from the Greek word ''orchis'' ('testicle'), in reference to the shape of the roo ...
'' * '' Acianthus'' * ''
Acineta ''Acineta'', abbreviated as Acn in horticultural trade, is a small genus belonging to the orchid family ( Orchidaceae). The name is derived from the Greek word 'akinetos' (immobile), referring to the rigid labellum (lip). These epiphytic orch ...
'' * '' Acrorchis'' * '' Ada'' * '' Aerangis'' * '' Aeranthes'' * '' Aerides'' * '' Aganisia'' * '' Agrostophyllum'' * ''
Anacamptis ''Anacamptis'' is a genus of flowering plants in the orchid family ( Orchidaceae); it is often abbreviated as Ant in horticulture. This genus was established by Louis Claude Richard in 1817; the type species is the pyramidal orchid (''A. pyr ...
'' * ''
Ancistrochilus ''Ancistrochilus'' is a genus of the orchid family (biology), family (Orchidaceae), comprising only 2 species. Description These two species are cool to hot growing orchids, found from tropical West Africa to Tanzania and Uganda. They grow on tr ...
'' * ''
Angraecum The genus ''Angraecum'', abbreviated as Angcm in horticultural trade, common name comet orchid, contains about 220 species. Etymology Despite the genus's distribution being largely confined to Africa and its offshore islands, the genus name is a ...
'' * '' Anguloa'' * '' Ansellia'' * '' Aorchis'' * ''
Aplectrum ''Aplectrum hyemale'' is a species of orchid native to the eastern United States and Canada, from Oklahoma east to the Carolinas and north to Minnesota, Ontario, Quebec and Massachusetts. It is particularly common in the Appalachian Mountains, th ...
'' * '' Arachnis'' * '' Arethusa'' * '' Armodorum'' * ''
Ascocentrum ''Vanda'', abbreviated in the horticultural trade as ''V.,'' is a genus in the orchid family, Orchidaceae. There are about 87 species, and the genus is commonly cultivated for the marketplace. This genus and its allies are considered to be among ...
'' * '' Ascoglossum'' * ''
Australorchis ''Dendrobium'' is a genus of mostly Epiphyte, epiphytic and Lithophyte, lithophytic orchids in the Family (biology), family Orchidaceae. It is a very large genus, containing more than 1,800 species that are found in diverse habitats throughout m ...
'' * '' Auxopus'' * '' Baptistonia'' * ''
Barkeria ''Barkeria'', abbreviated Bark in horticultural trade, is a genus of orchids. It consists of about 17 currently recognized (May 2014) species native to Mexico and Central America. This genus was once considered part of ''Epidendrum''. Type specie ...
'' * ''
Barlia ''Himantoglossum'' is a genus of orchids native to the Canary Islands, Europe, southwest Asia and northern Africa. Its members generally have a Labellum (botany), labellum which is divided into three parts, of which the middle part is the longest ...
'' * ''
Bartholina ''Bartholina'' is an orchid genus native to South Africa and Namibia. A member of the Fynbos plant kingdom, ''Bartholina'' is also known as the "spider orchid". The common name comes from the array of long, narrow petal lobes that surround the ...
'' * '' Beloglottis'' * '' Biermannia'' * ''
Bletilla ''Bletilla'', common name urn orchid, is a temperate, terrestrial genus of orchids containing five currently recognized species distributed through China, Japan, Taiwan, south to Vietnam, Thailand and Myanmar. The name is actually a diminutive ...
'' * ''
Brassavola ''Brassavola'' is a genus of 21 orchids (family Orchidaceae). They were named in 1813 by the Scottish botanist Robert Brown. The name comes from the Italian nobleman and physician Antonio Musa Brassavola. This genus is abbreviated B. in trade jo ...
'' * ''
Brassia ''Brassia'' is a genus of orchids classified in the subtribe Oncidiinae. It is native to Mexico, Central America, the West Indies, and northern South America, with one species (''B. caudata'') extending into Florida. The genus was named aft ...
'' * ''
Bulbophyllum ''Bulbophyllum'' is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is the largest genus in the orchid family and one of the largest genera of flowering plants with more than 2,000 species, exceeded in number o ...
'' * '' Calanthe'' * '' Calypso'' * ''
Catasetum ''Catasetum'', abbreviated as Ctsm. in horticultural trade, is a genus of showy epiphytic Orchids, family Orchidaceae, subfamily Epidendroideae, tribe Cymbidieae, subtribe Catasetinae, with 166 species, many of which are highly prized in hortic ...
'' * ''
Cattleya ''Cattleya'' () is a genus of orchids from Costa Rica south to Argentina. The genus is abbreviated C in trade journals. Description Epiphytic or terrestrial orchids with cylindrical rhizome from which the fleshy noodle-like roots grow. Ps ...
'' * ''
Chiloschista ''Chiloschista'', commonly known as starfish orchids and abbreviated ''Chsch.'', is a genus of usually leafless, epiphytic or lithophytic orchids found in India, Southeast Asia and Australia. Description Orchids in the genus ''Chiloschista'' ar ...
'' * ''
Cirrhopetalum ''Bulbophyllum'' sect. ''Cirrhopetalum'' is a Section (biology), section of the genus ''Bulbophyllum''. The taxon name comes from Latin ''cirrus'' (''fringe'') and Greek language, Greek ''petalon'' (''petal''), hence meaning ''fringed-petaled'' ...
'' * '' Cleisostoma'' * '' Clowesia'' * ''
Coelogyne ''Coelogyne'' is a genus of over 200 sympodial epiphytes from the family Orchidaceae, distributed across India, China, Indonesia and the Fiji islands, with the main centers in Borneo, Sumatra and the Himalayas. They can be found from tropical l ...
'' * ''
Coryanthes ''Coryanthes'', commonly known as bucket orchids, is a genus of neotropical epiphytic orchids (family Orchidaceae). This genus is abbreviated as Crths in horticultural trade. They are native to South America, Central America, Mexico and Trinida ...
'' * '' Cycnoches'' * ''
Cymbidium ''Cymbidium'' , commonly known as boat orchids, is a genus of evergreen flowering plants in the orchid family Orchidaceae. Orchids in this genus are epiphytic, lithophytic, terrestrial or rarely leafless saprophytic herbs usually with pseudob ...
'' * '' Cyrtopodium'' * ''
Cypripedium ''Cypripedium'' is a genus of 58 species and nothospecies of hardy orchids; it is one of five genera that together compose the subfamily of lady's slipper orchids ( Cypripedioideae). They are widespread across much of the Northern Hemisphere, i ...
'' * '' Dactylorhiza'' * ''
Dendrobium ''Dendrobium'' is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is a very large genus, containing more than 1,800 species that are found in diverse habitats throughout much of south, east and southeast Asi ...
'' * ''
Disa Disa is the heroine of a Swedish legendary saga, which was documented by Olaus Magnus, in 1555. It is believed to be from the Middle Ages, but includes Old Norse themes. It was elaborated by Johannes Messenius in his drama ''Disa'', which was t ...
'' * '' Dracula'' * '' Encyclia'' * ''
Epidendrum ''Epidendrum'' , abbreviated Epi in the horticultural trade, is a large neotropical genus of the orchid family. With more than 1,500 species, some authors describe it as a mega-genus. The genus name (from Greek ''επί, epi'' and ''δένδρο ...
'' * '' Epipactis'' * '' Eria'' * '' Eulophia'' * ''
Gastrochilus ''Gastrochilus'', abbreviated Gchls in horticultural trade, is a genus of plant in family Orchidaceae. It is native to eastern and southeastern Asia, including China, Japan, Bangladesh, Thailand, Malaysia, Indonesia, the Philippines, etc. Speci ...
'' * '' Gongora'' * ''
Goodyera ''Goodyera'', commonly called rattlesnake plantain, jade orchids or ladies' tresses is a wide-ranging genus of orchids in the tribe Cranichideae. About 100 species of ''Goodyera'' have been formally described. With a center of diversity in East ...
'' * ''
Grammatophyllum ''Grammatophyllum'', sometimes abbreviated in horticultural trade as Gram, is a genus of 13 currently known orchid species. The name is derived from the Greek words 'gramma' (a line or streak or mark) and 'phyllon' (leaf), referring to the parall ...
'' * '' Gymnadenia'' * '' Habenaria'' * '' Herschelia'' * '' Ionopsis'' * ''
Laelia ''Laelia'' is a small genus of 25 species in the orchid family (Orchidaceae). ''Laelia'' species are found in areas of subtropical or temperate climate in Central and South America, but mostly in Mexico. ''Laelia'' is abbreviated ''L.'' in the ...
'' * '' Lepanthes'' * '' Liparis'' * '' Ludisia'' * '' Lycaste'' * ''
Masdevallia ''Masdevallia'', abbreviated Masd in horticultural trade, is a large genus of flowering plants of the Pleurothallidinae, a subtribe of the orchid family (Orchidaceae). There are over 500 species, grouped into several subgenera. The genus is nam ...
'' * ''
Maxillaria ''Maxillaria'', abbreviated as Max in the horticultural trade, is a large genus of orchids (family Orchidaceae). This is a diverse genus, with very different morphological forms. Their characteristics can vary widely. They are commonly called s ...
'' * '' Meliorchis'' * ''
Mexipedium ''Mexipedium'' is a monotypic genus of the Orchid family Orchidaceae, subfamily Cypripedioideae, consisting of only one species, ''Mexipedium xerophyticum''. It is also the single genus of tribe Mexipedieae and subtribe Mexipediinae. Taxonomy an ...
'' * '' Miltonia'' * '' Mormodes'' * '' Odontoglossum'' * '' Oeceoclades'' * '' Oncidium'' * '' Ophrys'' * ''
Orchis ''Orchis'' is a genus in the orchid family (Orchidaceae), occurring mainly in Europe and Northwest Africa, and ranging as far as Tibet, Mongolia, and Xinjiang. The name is from the Ancient Greek ὄρχις ''orchis'', meaning "testicle", from ...
'' * ''
Paphiopedilum ''Paphiopedilum'', often called the Venus slipper, is a genus of the lady slipper orchid subfamily '' Cypripedioideae'' of the flowering plant family Orchidaceae. The genus comprises some 80 accepted taxa including several natural hybrids. The ...
'' * '' Papilionanthe'' * ''
Paraphalaenopsis The genus ''Paraphalaenopsis'', abbreviated as Prphln in horticultural trade, is a member of the orchid family (Orchidaceae), consisting of 4 species Endemism, endemic to Borneo and one natural (unconfirmed) hybrid, ''Paraphalaenopsis × thornton ...
'' * '' Peristeria'' * '' Phaius'' * ''
Phalaenopsis ''Phalaenopsis'' (), also known as moth orchids, is a genus of about seventy species of plants in the family Orchidaceae. Orchids in this genus are monopodial epiphytes or lithophytes with long, coarse roots, short, leafy stems and long-lasti ...
'' * ''
Pholidota Pangolins, sometimes known as scaly anteaters, are mammals of the order Pholidota (, from Ancient Greek ϕολιδωτός – "clad in scales"). The one extant family, the Manidae, has three genera: ''Manis'', ''Phataginus'', and ''Smutsia'' ...
'' * '' Phragmipedium'' * '' Platanthera'' * '' Platystele'' * '' Pleione'' * ''
Pleurothallis ''Pleurothallis'' is a genus of orchids commonly called bonnet orchids. The genus name is derived from the Greek word , meaning "riblike branches". This refers to the rib-like stems of many species. The genus is often abbreviated as "Pths" in hor ...
'' * ''
Pomatocalpa ''Pomatocalpa'', commonly known as bladder orchids, or 鹿角兰属 (lu jiao lan shu), is a genus of about twenty five species from the orchid family, Orchidaceae. Plants in this genus are epiphytes or lithophytes with thick, leathery leaves and ...
'' * '' Promenaea'' * ''
Pterostylis ''Pterostylis'' is a genus of about 300 species of plants in the orchid family, Orchidaceae. Commonly called greenhood orchids, they are terrestrial, deciduous, perennial, tuberous, herbs found in Australia, New Zealand, New Guinea, New Caled ...
'' * '' Renanthera'' * ''
Renantherella ''Renanthera'', abbreviated as Ren in horticultural trade, is a genus of large scrambling monopodial epiphytic and terrestrial species of orchid found in China, the Himalayas, Southeast Asia, New Guinea, and Melanesia.Rice, R. (2008). Renanthera ...
'' * '' Restrepia'' * '' Restrepiella'' * '' Rhynchostylis'' * ''
Roezliella ''Oncidium'', abbreviated as Onc. in the horticultural trade, is a genus that contains about 330 species of orchids from the subtribe Oncidiinae of the orchid family (Orchidaceae). As presently conceived (May 2014), it is distributed across much ...
'' * '' Saccolabium'' * ''
Sarcochilus ''Sarcochilus'', commonly known as butterfly orchids or fairy bells is a genus of about twenty species of flowering plants in the orchid family, Orchidaceae. Most species are epiphytes but a few species only grow on rocks or in leaf litter. Or ...
'' * '' Satyrium'' * '' Seidenfadenia'' * '' Selenipedium'' * '' Serapias'' * '' Sobralia'' * ''
Sophronitis ''Cattleya'' () is a genus of orchids from Costa Rica south to Argentina. The genus is abbreviated C in trade journals. Description Epiphyte, Epiphytic or terrestrial orchids with cylindrical rhizome from which the fleshy noodle-like roots ...
'' * ''
Spiranthes ''Spiranthes'' is a genus of orchids in the subfamily Orchidoideae. They are known commonly as ladies tresses, ladies'-tresses, or lady's tresses.Stanhopea ''Stanhopea'' is a genus of the orchid family (Orchidaceae) from Central and South America. The abbreviation used in horticultural trade is ''Stan.'' The genus is named for the 4th Earl of Stanhope (Philip Henry Stanhope) (1781-1855), president ...
'' * '' Stelis'' * '' Thrixspermum'' * ''
Tolumnia ''Tolumnia'' is the scientific name of two genera of organisms and may refer to: * ''Tolumnia'' (bug), a genus of insects in the family Pentatomidae * ''Tolumnia'' (plant), a genus of plants in the family Orchidaceae {{Genus disambiguation ...
'' * '' Trias'' * '' Trichocentrum'' * '' Trichoglottis'' * ''
Vanda ''Vanda'', abbreviated in the horticultural trade as ''V.,'' is a genus in the orchid family, Orchidaceae. There are about 87 species, and the genus is commonly cultivated for the marketplace. This genus and its allies are considered to be among ...
'' * '' Vanilla'' * '' Yoania'' * '' Zeuxine'' * '' Zygopetalum''


Etymology

The type
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
(i.e. the genus after which the family is named) is ''
Orchis ''Orchis'' is a genus in the orchid family (Orchidaceae), occurring mainly in Europe and Northwest Africa, and ranging as far as Tibet, Mongolia, and Xinjiang. The name is from the Ancient Greek ὄρχις ''orchis'', meaning "testicle", from ...
''. The genus name comes from the
Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
('), literally meaning "
testicle A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testoste ...
", because of the shape of the twin tubers in some species of ''Orchis''. The term "orchid" was introduced in 1845 by John Lindley in ''School Botany'', as a shortened form of ''Orchidaceae''. In
Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English ...
, the name ''bollockwort'' was used for some orchids, based on " bollock" meaning testicle and "
wort Wort () is the liquid extracted from the mashing process during the brewing of beer or whisky. Wort contains the sugars, the most important being maltose and maltotriose, that will be fermented by the brewing yeast to produce alcohol. Wort als ...
" meaning plant.


Hybrids

Orchid species hybridize readily in cultivation, leading to a large number of hybrids with complex naming. Hybridization is possible across genera, and therefore many cultivated orchids are placed into nothogenera. For instance, the nothogenus × ''Brassocattleya'' is used for all hybrids of species from the genera ''
Brassavola ''Brassavola'' is a genus of 21 orchids (family Orchidaceae). They were named in 1813 by the Scottish botanist Robert Brown. The name comes from the Italian nobleman and physician Antonio Musa Brassavola. This genus is abbreviated B. in trade jo ...
'' and ''
Cattleya ''Cattleya'' () is a genus of orchids from Costa Rica south to Argentina. The genus is abbreviated C in trade journals. Description Epiphytic or terrestrial orchids with cylindrical rhizome from which the fleshy noodle-like roots grow. Ps ...
''. Nothogenera based on at least three genera may have names based on a person's name with the suffix '' -ara'', for instance × ''Colmanara'' = '' Miltonia'' × '' Odontoglossum'' × '' Oncidium''. (The suffix is obligatory starting at four genera.) Cultivated hybrids in the orchid family are also special in that they are named by using grex nomenclature, rather than nothospecies. For instance, hybrids between ''
Brassavola nodosa ''Brassavola nodosa'' is a small, tough species of orchid native to Mexico (from Tamaulipas south to Chiapas and the Yucatán Peninsula), Central America, the West Indies, and northern South America (Venezuela, Colombia, Guyana and French Guian ...
'' and ''
Brassavola acaulis ''Brassavola'' is a genus of 21 orchids ( family Orchidaceae). They were named in 1813 by the Scottish botanist Robert Brown. The name comes from the Italian nobleman and physician Antonio Musa Brassavola. This genus is abbreviated B. in trade ...
'' are placed in the grex ''Brassavola'' Guiseppi. The name of the grex ("Guiseppi" in this example) is written in a non-italic font without quotes.


Abbreviations

As a unique feature of the orchid family, a system of abbreviations exists that applies to names of genera and nothogenera. The system is maintained by 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 (Nor ...
. These abbreviations consist of at least one character, but may be longer. As opposed to the usual one-letter abbreviations used for names of genera, orchid abbreviations uniquely determine the (notho)genus. They are widely used in cultivation. Examples are ''Phal'' for ''
Phalaenopsis ''Phalaenopsis'' (), also known as moth orchids, is a genus of about seventy species of plants in the family Orchidaceae. Orchids in this genus are monopodial epiphytes or lithophytes with long, coarse roots, short, leafy stems and long-lasti ...
'', ''V'' for ''
Vanda ''Vanda'', abbreviated in the horticultural trade as ''V.,'' is a genus in the orchid family, Orchidaceae. There are about 87 species, and the genus is commonly cultivated for the marketplace. This genus and its allies are considered to be among ...
'' and ''Cleis'' for '' Cleisostoma''.


Distribution

Orchidaceae are cosmopolitan, occurring in almost every
habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
apart from glaciers. The world's richest diversity of orchid genera and species is found 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 referr ...
, but they are also found above the Arctic Circle, in southern
Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and g ...
, and two species of ''
Nematoceras ''Corybas'', commonly known as helmet orchids, is a genus of about 120 species of plants in the orchid family, Orchidaceae. Helmet orchids are small, perennial, deciduous herbs and are nearly always terrestrial. They have a single leaf at their ...
'' on
Macquarie Island Macquarie Island is an island in the southwestern Pacific Ocean, about halfway between New Zealand and Antarctica. Regionally part of Oceania and politically a part of Tasmania, Australia, since 1900, it became a Tasmanian State Reserve in 197 ...
at 54° south. The following list gives a rough overview of their distribution: * Oceania: 50 to 70 genera * North America: 20 to 26 genera * tropical America: 212 to 250 genera * tropical Asia: 260 to 300 genera * tropical Africa: 230 to 270 genera * Europe and temperate Asia: 40 to 60 genera


Ecology

A majority of orchids are
perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wid ...
epiphytes, which grow anchored to
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 or shrubs 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 referr ...
and subtropics. Species such as ''
Angraecum The genus ''Angraecum'', abbreviated as Angcm in horticultural trade, common name comet orchid, contains about 220 species. Etymology Despite the genus's distribution being largely confined to Africa and its offshore islands, the genus name is a ...
sororium'' are lithophytes, growing on rocks or very rocky soil. Other orchids (including the majority of
temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout ...
Orchidaceae) are terrestrial and can be found in habitat areas such as grasslands or forest. Some orchids, such as ''
Neottia ''Neottia'' is a genus of orchids. The genus now includes the former genus ''Listera'', commonly known as twayblades referring to the single pair of opposite leaves at the base of the flowering stem. The genus is native to temperate, subarctic ...
'' and '' Corallorhiza'', lack chlorophyll, so are unable to photosynthesise. Instead, these species obtain energy and nutrients by parasitising soil fungi through the formation of
orchid mycorrhiza Orchid mycorrhizae are endomycorrhizal fungi which develop symbiotic relationships with the roots and seeds of plants of the family Orchidaceae. Nearly all orchids are myco-heterotrophic at some point in their life cycle. Orchid mycorrhizae are cr ...
e. The fungi involved include those that form ectomycorrhizas with trees and other woody plants, parasites such as ''
Armillaria ''Armillaria'' is a genus of fungi that includes the ''Armillaria mellea, A. mellea'' species known as honey fungi that live on trees and woody shrubs. It includes about 10 species formerly categorized summarily as ''A. mellea''. ''Armill ...
'', and
saprotroph Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ( ...
s. These orchids are known as
myco-heterotroph Myco-heterotrophy (from Greek μύκης , "fungus", ἕτερος ', "another", "different" and τροφή ', "nutrition") is a symbiotic relationship between certain kinds of plants and fungi, in which the plant gets all or part of its food fro ...
s, but were formerly (incorrectly) described as saprophytes as it was believed they gained their nutrition by breaking down organic matter. While only a few species are achlorophyllous holoparasites, all orchids are myco-heterotrophic during germination and seedling growth, and even photosynthetic adult plants may continue to obtain carbon from their mycorrhizal fungi. The symbiosis is typically maintained throughout the lifetime of the orchid because they depend on the fungus for nutrients, sugars and minerals. However, some orchids have been found to switch fungal partners during extreme conditions.


Uses


Perfumery

The
scent An odor (American English) or odour (Commonwealth English; see spelling differences) is caused by one or more volatilized chemical compounds that are generally found in low concentrations that humans and animals can perceive via their sense ...
of orchids is frequently analysed by perfumers (using headspace technology and
gas-liquid chromatography Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, ...
/ mass spectrometry) to identify potential fragrance chemicals.


Horticulture

The other important use of orchids is their cultivation for the enjoyment of the flowers. Most cultivated orchids are tropical or subtropical, but quite a few that grow in colder climates can be found on the market. Temperate species available at nurseries include ''
Ophrys apifera ''Ophrys apifera'', known in Europe as the bee orchid, is a perennial herbaceous plant of the family Orchidaceae. It serves as an example of sexually deceptive pollination and floral mimicry, as well as of a highly selective and highly evolved ...
'' (bee orchid), '' Gymnadenia conopsea'' (fragrant orchid), '' Anacamptis pyramidalis'' (pyramidal orchid) and ''
Dactylorhiza fuchsii ''Dactylorhiza fuchsii'', the common spotted orchid, is a species of flowering plant in the orchid family Orchidaceae. ''Dactylorhiza fuchsii'' is one of Europe's commonest wild orchids. It is widespread across much of Europe, with the range ex ...
'' (common spotted orchid). Orchids of all types have also often been sought by collectors of both species and hybrids. Many hundreds of societies and clubs worldwide have been established. These can be small, local clubs, or larger, national organisations such as the American Orchid Society. Both serve to encourage cultivation and collection of orchids, but some go further by concentrating on conservation or research. The term "botanical orchid" loosely denotes those small-flowered, tropical orchids belonging to several genera that do not fit into the "florist" orchid category. A few of these genera contain enormous numbers of species. Some, such as ''
Pleurothallis ''Pleurothallis'' is a genus of orchids commonly called bonnet orchids. The genus name is derived from the Greek word , meaning "riblike branches". This refers to the rib-like stems of many species. The genus is often abbreviated as "Pths" in hor ...
'' and ''
Bulbophyllum ''Bulbophyllum'' is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is the largest genus in the orchid family and one of the largest genera of flowering plants with more than 2,000 species, exceeded in number o ...
'', contain approximately 1700 and 2000 species, respectively, and are often extremely vegetatively diverse. The primary use of the term is among orchid hobbyists wishing to describe unusual species they grow, though it is also used to distinguish naturally occurring orchid species from horticulturally created hybrids. New orchids are registered with the International Orchid Register, maintained by 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 (Nor ...
.


Food

The dried seed pods of one orchid genus, '' Vanilla'' (especially '' Vanilla planifolia''), are commercially important as a flavouring in baking, for
perfume Perfume (, ; french: parfum) is a mixture of fragrant essential oils or aroma compounds (fragrances), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agreeable scent. Th ...
manufacture and
aromatherapy Aromatherapy is based on the usage of aromatic materials including essential oils and other aroma compounds, with claims for improving psychological and physical well-being. It is offered as a complementary therapy or as a form of alternative ...
. The underground tubers of terrestrial orchids ainly_''Orchis_mascula''_(early_purple_orchid).html" ;"title="Orchis_mascula.html" ;"title="ainly ''Orchis mascula">ainly ''Orchis mascula'' (early purple orchid)">Orchis_mascula.html" ;"title="ainly ''Orchis mascula">ainly ''Orchis mascula'' (early purple orchid)are ground to a powder and used for cooking, such as in the hot beverage ''salep'' or in the Turkish cuisine, Turkish mastic ice cream ''dondurma''. The name ''salep'' has been claimed to come from the Arabic expression ', "fox testicles", but it appears more likely the name comes directly from the Arabic name '. The similarity in appearance to testes naturally accounts for ''salep'' being considered an aphrodisiac. The dried leaves of ''
Jumellea fragrans ''Jumellea fragrans'' is a species of orchid in the genus ''Jumellea''. It is native to the islands of Mauritius and Réunion. It grows as an epiphyte in the lowland rain forest up to 500 m above sea level. The species blooms in March-April wit ...
'' are used to flavour rum on
Reunion Island Reunion may refer to: * Class reunion * Family reunion Reunion, Réunion, Re-union, Reunions or The Reunion may also refer to: Places * Réunion, a French overseas department and island in the Indian Ocean * Reunion, Commerce City, Colorado, ...
. Some saprophytic orchid species of the group '' Gastrodia'' produce potato-like tubers and were consumed as food by native peoples in Australia and can be successfully cultivated, notably '' Gastrodia sesamoides''. Wild stands of these plants can still be found in the same areas as early Aboriginal settlements, such as Ku-ring-gai Chase National Park in Australia.
Aboriginal peoples Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...
located the plants in habitat by observing where
bandicoot Bandicoots are a group of more than 20 species of small to medium-sized, terrestrial, largely nocturnal marsupial omnivores in the order Peramelemorphia. They are endemic to the Australia–New Guinea region, including the Bismarck Archipelago t ...
s had scratched in search of the tubers after detecting the plants underground by scent.


Cultural symbolism

Orchids have many associations with symbolic values. For example, the orchid is the City Flower of
Shaoxing Shaoxing (; ) is a prefecture-level city on the southern shore of Hangzhou Bay in northeastern Zhejiang province, China. It was formerly known as Kuaiji and Shanyin and abbreviated in Chinese as (''Yuè'') from the area's former inhabitant ...
, China. '' Cattleya mossiae'' is the national Venezuelan flower, while ''
Cattleya trianae ''Cattleya trianae'' (Lind. & Rchb. fil), also known as ''Flor de Mayo'' ("May flower") or "Christmas orchid", is a plant of the family Orchidaceae. It grows as an epiphytic orchid, with succulent leaves, endemic to Colombia where it was nomin ...
'' is the national flower of Colombia. ''Vanda'' Miss Joaquim is the national flower of
Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, bor ...
, '' Guarianthe skinneri'' is the national flower of Costa Rica and '' Rhyncholaelia digbyana'' is the national flower of Honduras. '' Prosthechea cochleata'' is the national flower of
Belize Belize (; bzj, Bileez) is a Caribbean and Central American country on the northeastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a wate ...
, where it is known as the ''black orchid''. '' Lycaste skinneri'' has a white variety (alba) that is the national flower of Guatemala, commonly known as ''Monja Blanca'' (White Nun).
Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Co ...
's national flower is the ''Holy Ghost orchid'' ('' Peristeria elata''), or 'the flor del Espiritu Santo'. ''Rhynchostylis'' ''retusa'' is the state flower of the Indian state of
Assam Assam (; ) is a state in northeastern India, south of the eastern Himalayas along the Brahmaputra and Barak River valleys. Assam covers an area of . The state is bordered by Bhutan and Arunachal Pradesh to the north; Nagaland and Manipur ...
where it is known as ''Kopou Phul.'' Orchids native to the Mediterranean are depicted on the ''
Ara Pacis The Ara Pacis Augustae (Latin, "Altar of Augustan Peace"; commonly shortened to Ara Pacis) is an altar in Rome dedicated to Pax, the Roman goddess of Peace. The monument was commissioned by the Roman Senate on July 4, 13 BC to honour the return o ...
'' in Rome, until now the only known instance of orchids in ancient art, and the earliest in European art. A and B Larsen orchids - Cattleya Mrs Mahler Mem Fred Tompkins 659-9.jpg, ''Cattleya'' Mrs. Mahler 'Mem. Fred Tompkins' File:A and B Larsen orchids - Cattleya Queen Sirikhit Diamond Crown DSCN4414.JPG, ''Cattleya'' Queen Sirikit 'Diamond Crown' A and B Larsen orchids - Cattleya Hawaiian Wedding Song Virgin 674-23.jpg, ''Cattleya'' Hawaiian Wedding Song 'Virgin' Blc Chia-lin.jpg, ''Rhyncholaeliocattleya'' Chia Lin A and B Larsen orchids - Cattleya Hawaian Variable Prasan 336-2.jpg, ''Cattleya'' Hawaiian Variable 'Prasan' File:A and B Larsen orchids - Cattleya Barbara Belle DSCN8696.JPG, ''Cattlianthe'' Barbara Belle File:Cattleya Beaumesnil Parme 1001 Orchids.jpg, ''Cattleya'' Beaumesnil 'Parme' File:A and B Larsen orchids - Cattleya Chocolate Drop x Pao de Acucar 507-21.jpg, ''Cattlianthe'' Chocolate Drop x ''Cattleya'' Pão de Açúcar File:Cattleya Empress Frederick C mossiae.jpg, '' Cattleya mossiae'' 'Empress Frederick' File:Cattleya Hermine.jpg, 'Hermine' File:A and B Larsen orchids - Cattleya Little AngelDSCN3349.JPG, ''Cattleya'' Little Angel File:A and B Larsen orchids - Cattleya Marjorie Hausermann York 812-4.jpg, ''Cattleya'' Marjorie Hausermann 'York' File:A and B Larsen orchids - Cattleya Miva Breeze Alize 930-23.jpg, 'Miva Breeze Alize' File:Blc Nobiles carnival.jpg, ''Rhyncholaeliocattleya'' 'Nobile's carnival' File:Cattleya Pernell George Barnett "Yankee Clipper" (3072486817).jpg, ''Cattleya'' Pernel George Barnett 'Yankee Clipper' File:Cattleya Portia.jpg, ''Cattlianthe'' Portia


Conservation

Almost all orchids are included in Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade (including in their parts/derivatives) is regulated by the CITES permit system. A smaller number of orchids such as ''Paphiopedilum'' sp. are listed in CITES Appendix I meaning that commercial international trade in wild-sourced specimens is prohibited and all other trade is strictly controlled.


Assisted migration as conservation tool

In 2006 the
Longtan Dam Longtan Dam () is a large roller-compacted concrete (RCC) gravity dam on the Hongshui River in Tian'e County of the Guangxi Zhuang Autonomous Region, China, a tributary of the Xi River and the Pearl River. The dam is high and long; it is the ...
was constructed at the Hongshui River, near the Yachang Orchid Nature Reserve. In response to threats of
inundation A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrolog ...
of wild orchids at lower altitudes (350-400 m above sea level), 1000 endangered orchid plants of 16 genera and 29 species were translocated to higher elevation (approximately 1000 m above sea level). After relocation the 5 year survival of low and wide elevation species did not significantly differ and the mortality due to
transplant shock In agriculture and gardening, transplanting or replanting is the technique of moving a plant from one location to another. Most often this takes the form of starting a plant from seed in optimal conditions, such as in a greenhouse or protected n ...
was at only 10%. From this it was concluded that assisted migration might be a viable conservation tool for orchid species endangered by
climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
.


See also

* ''Adaptation'' (film), based on ''
The Orchid Thief ''The Orchid Thief'' is a 1998 non-fiction book by American journalist Susan Orlean, based on her investigation of the 1994 arrest of horticulturist John Laroche and a group of Seminoles in south Florida for poaching rare orchids in the Faka ...
'' * Distribution of orchid species * Orchid Conservation Coalition *
Orchid Pavilion Gathering The Orchid Pavilion Gathering of 353 CE, also known as the Lanting Gathering, was a cultural and poetic event during the Jin dynasty (266–420) of the Six Dynasties era, in China. This event itself has a certain inherent and poetic interest in reg ...
* Orchidelirium, the Victorian era of flower madness in which collecting and discovering orchids reached extraordinary levels *
Orchids of the Philippines There are about 141 genera of orchids representing about 1,100 orchid species, 900 of which are described as endemic to the Philippines. Many of them have showy, brightly colored and attractive flowers. '' Vanda sanderiana'' is unofficially dubb ...
* Orchids of Western Australia *
Shangsi Festival The Key Holiday () is a keyholiday originated from China, and is celebrated in multiple East Asian countries, including China and Korea. China The Double Third Festival () or Shangsi Festival () is a Chinese festival celebrated on the third ...
* Black rot on orchids * List of taxa named after human genitals


Notes


References


Bibliography

*


External links


Orchidaceae observations at iNaturalistOrchidaceae
a
''The Plant List''


at th
''Angiosperm Phylogeny Website''

World checklist of Orchidaceae species from the Catalogue of Life
29,572 species supplied by World Checklist of Selected Plant Families (R. Govaerts & al.)
Orchidaceae
at the onlin
''Flora of North America''

Orchidaceae
at the online ''Flora of China''
Orchidaceae
at the onlin
''Flora of Zimbabwe''

Orchidaceae
at the onlin
''Flora of the Western Australian''

Orchidaceae
at the onlin
''Flora of New Zealand''

The Global Orchid Information Network

Orchid Conservation Coalition
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