Orchidaceae - Revision history

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{{Taxobox
| color = lightgreen
| name = Orchids
| image = Haeckel Orchidae.jpg
| image_caption = Color plate from [[Ernst Haeckel]]'s ''[[Kunstformen der Natur]]''
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Monocotyledon|Liliopsida]]
| ordo = [[Asparagales]]
| familia = '''Orchidaceae'''
| familia_authority = [[Antoine Laurent de Jussieu|Juss.]]
| subdivision_ranks = Subfamilies
| subdivision =
* [[Apostasioideae]]
* [[Cypripedioideae]]
* [[Epidendroideae]]
* [[Orchidoideae]]
* [[Vanilloideae]]
For genera, see [[list of Orchidaceae genera]].
}}
'''Orchids''' ('''Orchidaceae''' family) are the largest and most diverse of the [[flowering plant]] ([[Angiospermae]]) families, with over 800 described [[genus|genera]] and 25,000 [[species]]. Some sources give 30,000 species, but the exact number is unknown since classification differs greatly in the academic world. Revisions of different genera occur on a monthly basis and this will increase with the growing use of genetic research and biochemistry. There are another 100,000+ [[hybrid]]s and [[cultivar]]s produced by [[horticulture|horticulturists]], created since the introduction of tropical species in the 19th century. The Kew ''World Checklist of Orchids'' includes about 24,000 accepted species. About 800 new species are added each year. Orchids, through their interactions with [[pollinator]]s and their [[symbiosis]] with [[Orchid mycorrhiza|orchid mycorrhizal]] fungi, are considered by some, along with the [[Poaceae|grasses]], to be examples of the most advanced (derived) floral [[evolution]] known.

All orchid species are protected for the purposes of international commerce under [[CITES]] as potentially threatened or endangered in their natural habitat, with most species listed under Appendix II. A number of species and genera are afforded protection under Appendix I, including all ''[[Paphiopedilum]]'', ''[[Phragmipedium]]'', ''[[Mexipedium]]'', ''[[Cypripedium]]'', and ''[[Selenipedium]]'' species. Many other species are protected by both international and national legislation, while hybrids are supposed to be specifically exempted, hybrid orchids are not allowed into the United States without a CITES permit. Reason that is given is that the authorities can not distinguish the difference between hybrids and species.{{Fact|date=February 2007}}

==Naming==
Orchids get their name from the [[Greek language|Greek]] ορχις ''orchis'', meaning "testicle", from the appearance of subterranean tuberoids of the genus ''[[Orchis]]''. The word "orchis" was first used by [[Theophrastos]] ([[372 BC|372]]/[[371 BC|371]] – [[287 BC|287]]/[[286 BC]]), in his book "De historia plantarum" (The natural history of plants). He was a student of [[Aristotle]] and is considered the father of [[botany]] and [[ecology]].

==Appearance and Structure==
Orchids like the [[Grass|grasses]] and the [[palm]]s, which they resemble in some ways—for instance the form of their leaves—are [[monocotyledon]]s. They have one [[cotyledon]], or embryo leaf, in contrast to the two of most flowering plants.

Orchids are [[cosmopolitan distribution|cosmopolitan]] in distribution, occurring in every [[Habitat (ecology)|habitat]], except [[Antarctica]] and deserts. The great majority are to be found in the [[tropics]], mostly [[Asia]], [[South America]] and [[Central America]]. They are found above the Arctic Circle, in southern [[Patagonia]] and even on [[Macquarie Island]], close to Antarctica.

The following list gives a rough overview of their distribution:
* Eurasia: 40–60 genera
* North America: 20–30 genera
* tropical America: 300–350 genera
* tropical Africa: 125–150 genera
* tropical Asia: 250–300 genera
* Oceania: 50–70 genera

Orchids can be grouped according to the way they retrieve nutrients:
* A majority of species are [[perennial]] [[epiphyte]]s; they are found in [[tropical moist broadleaf forests]] or mountains and subtropics. These are anchored on other plants, mostly [[tree]]s, someti
mes [[shrub]]s. However, they are not [[parasite]]s.
* A few are [[lithophyte]]s, similar to epiphytes but growing naturally on rocks or on very rocky soil. They derive their nutrients from the atmosphere, rain water, litter, [[humus]], and even their own dead tissue.
* Others are [[terrestrial plant]]s. They grow in the soil or in the loose substrate atop the ground and obtain their nutrients from the soil or the substrate. This group includes nearly all temperate orchids.
* Some lack [[chlorophyll]] and are [[myco-heterotrophs]] (formerly incorrectly called [[saprophytes]]). These achlorophyllous orchids have an ectomycorrhizal relationship, i.e. they are completely dependent on soil [[fungi]] feeding on decaying plant matter (usually fallen [[leaf|leaves]]) to provide them with nutrients. Typical examples include the [[Bird's-nest Orchid]] (''Neottia nidus-avis'') and Spotted Coral-root (''[[Corallorrhiza maculata]]'').

Most advanced orchids have these five basic features:
*The presence of a [[column (botany)|column]], also called gynostemium
*The flower is [[symmetry (biology)#Bilateral symmetry|bilaterally symmetric]] ([[zygomorphic]])
*The [[pollen]] are glued together into the [[pollinium|pollinia]], a mass of waxy pollen on filaments.
*The [[seed]]s are microscopically small, lacking [[endosperm]] (food reserves) in the overall majority of the species. There are notable exceptions, such as ''[[Disa (orchid)|Disa]] cardinalis'', whose seeds may grow to a length of 1.1 mm. Seeds of ''[[Vanilla (orchid)|Vanilla]]'' may weigh 20 times or more than that of other orchids. They and their surrounding pulp within the seed pod are used in the food industry as the extremely popular flavoring "vanilla extract".
*The seeds can, under natural circumstances, only germinate in [[symbiosis]] with specialized fungi. Under artificial circumstances, however, germination is possible "''in vitro''" on sterile substrates of [[agar]] in specialized laboratories. Germinating seeds in agar, usually done in flasks, is an advanced technique, requiring sterility at all costs. It takes anywhere from one–up to five to ten years for an orchid seedling to mature. An alternative type artificial germination, however, is done by cultivating the fungus and sowing the seeds on them. This is called in-vitro symbiotic culture and is used most commonly for terrestrial orchids.

==Leaves==

[[image:Dendrobium crumenatum.jpg|thumb|250px|right|This small orchid demonstrates a typical [[zygomorphic]] flower with three petal-like [[sepal]]s (top, lower right, lower left), two normal [[petal]]s on either side of the dorsal (upper) sepal, and the [[labellum]], a modified lower petal in three parts surrounding and below the shiny column.]]
Orchids have simple [[Leaf|leaves]] with parallel [[vein]]s. Their shape is highly variable between species; ovate, lanceolate, or orbiculate. Their size and shape can be an aid in identifying the orchid, since it reflects the taxonomic position. The leaves can be enormous or minute, or they can even be lacking (as in the [[Ghost Orchid]] (''Dendrophylax lindenii''), a mycoheterotrophic species, and ''[[Aphyllorchis]]'' and ''[[Taeniophyllum]]'', which depend on their roots, which contain chlorophyll for [[photosynthesis]]).

The structure of the leaves corresponds to the specific habitat of the orchid. Species that typically bask in sunlight, or grow on sites which can be occasionally very dry, have thick, leathery leaves. The [[lamina]]s are covered by a waxy [[cuticle]]. These retain their necessary water supply. Shade species, on the other hand, have tall, thin leaves. They cannot tolerate a drop in atmospheric humidity or exposure to direct sunlight. Between these two extremes, there is a whole range of intermediate forms.

The leaves of most orchids live on, attached to their [[pseudobulbs]], for several years. Some species, especially those with plicate leaves, shed their aged leaves annually, through an articulation between the lamina and the [[Petiole (botany)|petiole]] sheath, and develop new leaves together with
new pseudobulbs (as in the genus ''[[Catasetum]]'').

The leaves of some species can be most beautiful. The leaves of the ''Macodes sanderiana'', a semiterrestrial or lithophyte, show a sparkling silver and gold veining on a light green background. The cordate leaves of ''Psychopsiella limminghei'' are light brownish green with maroon-puce markings, created by flower pigments. The attractive mottle of the leaves of [[Lady's Slipper]]s from temperate zones (''[[Paphiopedilum]]'') is caused by uneven distribution of chlorophyll. Also ''Phalaenopsis schilleriana'' is a lovely 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 fairly inconspicuous white flowers.

==Stem==
The stem of an orchid determines the habit of the species. Each type of stem can grow in one of these two ways:
*[[monopodial]] ("one-footed") growth. The new shoots grow upwards from a single stem, originating in the end bud of the old shoots. It then produces leaves and flowers along this stem. The stem of these orchids can reach a length of several meters (as in the genera ''[[Vanda]]'' and ''[[Vanilla]]'').
*[[sympodial]] ("many-footed") growth. The plant produces a series of adjacent shoots which grow to a certain size, bloom, then stop growing, to be replaced by the next growth. Plants of this type grow laterally 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 the genus ''[[Cattleya]]''). While this lead is developing, the rhizome may start its growth again, this time from an 'eye', or undeveloped bud, thereby causing the rhizome to branch.

==Plant thallus and roots==

[[image:Pseudobulbs_new.jpg|thumb|right|[[Pseudobulb]]s of an [[epiphytic]] orchid]]
All orchids are [[perennial]] herbs, lacking any permanent [[wood]]y structure.
*Some orchids are terrestrial, growing rooted in the [[soil]]. Terrestrial orchids may be [[rhizome|rhizomatous]], forming '''[[corm]]s''' or '''[[tuber]]s'''. These act as storage organs for food and water. The root caps of terrestrials are smooth and white. Terrestrials are mostly found in colder climates.
*A great many orchids are [[epiphyte]]s, which do not require soil and use trees for support. They occur in warmer regions. Epiphytic orchids have modified [[aerial root]]s and, in the older parts of the root, an [[Epidermis (botany)|epidermis]] modified into a spongy, water-absorbing '''[[velamen]]''', which can have a silvery-gray, white or brown appearance. The cells of the root epidermis grow at a right angle to the axis of the root. This allows them to get a firm grasp on their support. These roots can sometimes be a few meters long, in order to take up as much moisture as possible. Nutrients mainly come from animal droppings on their supporting tree that are washed down when it rains. The aerial roots of epiphytes that lack leaves have an additional function. They contain chlorophyll and take up [[carbon dioxide]].
*Several species are [[lithophyte]]s, especially in rocky mountain ranges in [[Australia]] and [[Tasmania]], central [[Brazil]] and [[Africa]].

The base of the stem of sympodial epiphytes, or in some species essentially the entire stem, may be thickened to form what is called a ''',[[pseudobulb]]'''. These contain nutrients and water for drier periods. Pseudobulbs have a smooth surface with lengthwise grooves. They typically stay alive for five or six years. They look on the inside more like a corm than the embryonal stage of leaf sheaths. They have different sizes and shapes. They can be conical or oblong. In the Black Orchids (''[[Bulbophyllum]]''), the pseudobulbs are no longer than 2 mm. The largest orchid in the world, the [[Giant Orchid]] (''Grammatophyllum speciosum''), has pseudobulbs with lengths of 2–3 m. When the orchid has aged and the pseudobulb has shed its leaves, the pseudobulb becomes dormant and is called
a '''backbulb'''. The next year's pseudobulb then takes over, exploiting the last reserves of the backbulb. Eventually, the backbulb also dies off, having given life to newer growths. At the end of the pseudobulb typically appear one or two leaves, though there may be up to a dozen or more. Some ''[[Dendrobium]]'' have long, canelike pseudobulbs with short, rounded leaves over the whole length. Some orchids have hidden or extremely small pseudobulbs hidden completely inside leaves.

Some sympodial terrestrials, such as ''Orchis'' and ''[[Ophrys]]'', have two subterranean tubers (more like [[tuberous root]]s) between the [[root]]s. One is used as a food reserve for wintery periods, and provides for the development of the other pseudobulb, from which visible growth develops.

In warm and humid climates, many terrestrial orchids do not need pseudobulbs.

==Orchid flowers==
[[Image:Calopogon.web.jpg|thumb|right|250px|Calopogon orchid]]
[[Image:Rainforestorchid.jpg|thumb|right|250px|Wild orchid from Sumatran Rainforest]]
There are many types of [[specialization]]s within the Orchidaceae. Best known are the seemingly endless structural variations in the [[flower]]s that encourage [[pollination]] by particular species of [[insect]]s, [[bat]]s, or [[bird]]s.

Most African orchids are white, while Asian orchids are often multicolored. Some orchids only grow one flower on each stem, others sometimes more than a hundred together on a single spike.

The typical orchid flower is [[zygomorphic]], i.e. [[symmetry (biology)#Bilateral symmetry|bilaterally symmetric]]. Notable exceptions are the genera ''Mormodes'', ''Ludisia'' and ''Macodes''.

The flowers grow on [[raceme]]s or [[panicle]]s. These can be :
* basal (i.e. produced from the base of the pseudobulb, as in ''[[Cymbidium]]'')
* apical (i.e. produced from the apex of the orchid, as in ''[[Cattleya]]'')
* or axillary (i.e. coming from a node between the leaf axil and the plant axis, as in ''[[Vanda]]'').

The basic orchid flower is composed of three [[sepal]]s in the outer whorl, and three [[petal]]s in the inner whorl. The medial petal is usually modified and enlarged (then called the '''[[labellum]]''' or lip), forming a platform for pollinators near the center of the [[corolla]]. Together, except the lip, they are called '''[[tepal]]s'''.

Sepals form the exterior of the bud. They are green in this stage, but sometimes, if the orchid blossom is, for example, purple, the buds can show a purple tint. When the flower opens, the sepals become intensely colored. Sepals may mimic petals such as in some phalaenopsis or be completely distinct. In many orchids, the sepals are mutually different and generally resemble the petals. It is not always easy to distinguish sepals and petals. The normal form can be found in ''[[Cattleya]]'', with three sepals forming a triangle. But in Venus Slippers (''Paphiopedilum'') the lower two sepals are concrescent (fused together into a [[synsepal]]), while the lip has taken the form of a slipper. In ''[[Masdevallia]]'' all the sepals are fused into a [[calyx (flower)|calyx]]. In an example like this the sepals are very prominent, especially in lycaste orchids, the actual petals become diminished and inconspicuous.

The [[reproductive organ]]s in the center ([[stamen]]s and [[carpel|pistil]]) have adapted to become a cylindrical structure called the [[column (botany)|column]] or gynandrium. On top of the column lies the [[Carpel|stigma]], the vestiges of stamens and the [[Pollinium|pollinia]], a mass of waxy [[pollen]] on filaments. These filaments can be a '''[[caudicle]]''' (as in ''[[Habenaria]]'') or a '''[[stipe (botany)|stipe]]''' (as in ''[[Vanda]]''). These filaments hold the pollinia to the '''[[viscidium]]''' (sticky pad). The pollen are held together by the [[alkaloid]] [[viscine]]. This viscidium adheres to the body of a visiting insect. The type of pollinia is useful in determining the genus. On top of the pollinia is the '''[[anther cap]]''', preventing self-pollination. At the upper edge of the stigma of single-anthered orchids,
in front of the anther cap, is the '''[[rostellum]]''', a slender beaklike extension.

==Reproduction==
[[Image:Ophrys-bombyliflora.web.jpg|thumb|right|250px|[[Bumblebee Orchid]] (''Ophrys bombyliflora'')]]
It is in the variety and the refinement of their [[Reproduction|reproductive]] methods that orchids truly amaze. On many orchids, the lip ([[labellum]]) serves as a landing pad for flying insects. The labellum is sometimes adapted to have a color and shape which attracts particular male insects via mimicry of a receptive female insect. Some orchids are reliant solely on this deception for pollination. After pollination, the epigynous [[ovary (plants)|ovary]] starts developing and produces a many-seeded [[capsule (fruit)|capsule]].
*The Lady's Slipper (''[[Paphiopedilum]]'') has a deep pocket that traps visiting insects, with just one exit. Passage through this exit leads to [[pollinium|pollinia]] being deposited on the insect.
*Many neotropical orchids are pollinated by male [[euglossini|orchid bees]], which visit the flowers to gather volatile chemicals they require to synthesize [[pheromone|pheromonal]] attractants. 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 Eurasian genus ''Ophrys'' has some species that look and smell so much like female [[bumblebee]]s that male bees flying nearby are irresistibly drawn in and attempt to mate with the flower, such as with the [[Bumblebee Orchid]] (''Ophrys bombyliflora''). The viscidium, and thus pollinia, stick to the head or the abdomen of the bumblebee. On visiting another orchid of the same species, the bumblebee pollinates the sticky stigma with the pollinia. The filaments of the pollinia have, during transport, taken such position that the waxy pollen are able to stick in the second orchid to the stigma, just below the rostellum. Such is the refinement of the reproduction. If the filaments had not taken the new position on the bee, the pollinia could not have pollinated the original orchid. Other species of ''Ophrys'' are mimics of different bees or wasps, and are also pollinated by males attempting to mate with the flowers, and other orchid genera practice similar deception.
*An underground orchid in Australia, ''[[Rhizanthella slateri]]'', never sees the light of day, but depends on [[ant]]s and other terrestrial insects to pollinate it.
*Many ''[[Bulbophyllum]]'' species stink like [[Decomposition|rotting]] [[carcass]]es, and the [[Fly|flies]] they attract assist their reproduction.
*''Catasetum saccatum'', a species discussed briefly by [[Charles Darwin|Darwin]] actually launches its viscid pollen sacs with explosive force, when an insect touches a [[seta]]. He was ridiculed for reporting this by the naturalist [[Thomas Huxley]].
*Some ''[[Phalaenopsis]]'' species in [[Malaysia]] are known to use subtle weather cues to coordinate mass flowering.
*Some ''Phalaenopsis'', ''Dendrobium'' and ''Vanda'' species produce [[keiki]], offshoots or plantlets formed from one of the [[node (botany)|node]]s along the [[Plant stem|stem]], through the accumulation of growth hormones at that point.
The filaments of the pollinia of some orchids dry up if they haven’t been visited by an insect. This way, the waxy pollen falls on the stigma causing the orchid to self-fertilize.
*''[[Holcoglossum]] amesianum'', native to China's [[Yunnan]] province, reproduces in a hermaphroditic manner, fertilizing itself by rotating its anther and insert it into the flower's stigma cavity. This mode of pollination is likely due to the lack of wind and insects in the region where this species grows. The [[Bee orchid]] uses a similar method of selfpollination.

==Fruits and seeds==
[[Image:Kapselquerschnitte Orchideen.png|thumb|right|200px|cross-section of an orchid capsule, showing 3 or 6 longitudinal slits]]
The orchid [[ovary (plants)|ovary]] is always inferior (located behind the flower), three-[[carpel]]ate and one or three-partitioned, with parietal [[placenta]]tion (but axile in the [[Apostasioidea
e]]).

If pollination was successful, the sepals and petals fade and wilt but they remain attached to the ovary. The epigynous ovary typically develops into a [[capsule (fruit)|capsule]] that is [[dehiscent]] by 3 or 6 longitudinal slits, while remaining closed at both ends. The [[ripe]]ning of a capsule can take 2–18 months. The microscopic [[seed]]s are very numerous (over a million per capsule in most species). They blow off after ripening like dust particles or spores, barely visible to the human eye. Since they lack [[endosperm]], they must enter symbiotic relationship with mycorrhizal fungi to germinate. These fungi provide the necessary nutrients to the seeds.
[[Image:Random 010e.jpg|thumb|left|150px|An orchid seed capsule]]

All orchid species are reliant upon [[Orchid mycorrhiza|mycorrhizal]] associations with various [[basidiomycete]]ous [[fungi]] to complete their lifecycle. Although all orchids are mycoheterotrophic during germination, some achlorophyllous (lacking chlorophyll) species are entirely dependent upon these fungi for nutrients. In general, orchid mycorrhizal fungi [[Decomposition|decompose]] organic matter and subsequently [[translocate]] the obtained nutrients via their [[hyphae]] to the orchid. Because most orchid seeds are extremely tiny with no food reserves ([[endosperm]] lacking), they will not germinate without such a [[symbiosis|symbiont]] to supply nutrients in the wild. Some fungi continue to live in the roots of the adult orchid. This enables an orchid such as ''[[Neottia nidus-avis]]'' to function without chlorophyll. The chance for a seed to meet a fitting fungus is very small. Of all the seeds released, only a minute fraction grow into new orchids. This process can take years; in some cases up to fifteen years.

[[Horticultural]] techniques have been devised for germinating seeds on a nutrient-containing gel, eliminating the requirement of the fungus for germination, and greatly aiding the propagation of rare and endangered species.

==Orchids in commerce==
[[Image:Orchid.jpg|thumb|left|250px|Phalaenopsis hybrid]]
One orchid genus, ''Vanilla'', is commercially important, used as a foodstuff flavoring, the source of [[vanilla]]. The underground tubers of terrestrial orchids are ground to a powder and used for cooking, such as in the hot beverage [[salep]] or the so-called "fox-testicle ice cream" [[salepi dondurma]]. The scent of orchids is frequently used by [[Perfume|perfumists]] (using [[Gas-liquid chromatography]]) to identify potential fragrance chemicals. With these exceptions, orchids have virtually no commercial value other than for the enjoyment of the flowers (see also [[Botanical orchids]]).

There are a great number of [[tropical]] and [[subtropical]] orchids, and these are the most commonly known, as they are available at nurseries and through orchid clubs across the world. There are also quite a few orchids which grow in colder climates, although these are less often seen on the market. Temperate species available at nurseries include ''[[Ophrys apifera]]'' (bee orchid), ''[[Gymnadenia conopsea]]'' (fragrant orchid), ''[[Anacamptis pyramidalis]]'' (pyramidal orchid) and ''[[Dactylorhiza fuchsii]]'' (common spotted orchid).

The family of orchids is remarkably diverse. The plants found in "casual" culture, such as ''[[Phalaenopsis]]'', ''[[Cattleya]]'', ''[[Dendrobium]]'', and so forth, represent a tiny fraction of the thousands of species of orchids. Also within the Orchidaceae are "[[leaf]]less" orchids, which often appear as nothing more than masses of [[root]]s, achlorophyllous orchids that are entirely reliant upon their mycorrhizal symbiont for their nutrition, "jewel" orchids with foliage that is as pretty as their flowers, and so many others that are capable of affecting the most dedicated of growers very deeply. Ranging in size from tiny moss-like ''[[Pleurothallis]]'' species to massive (7 m) ''[[Grammatophyllum]]'' species in [[New Guinea]], their beauty and sophistication have captivated many.

The National Orchid Garden in the [[Singapore]] [[Sing
apore Botanic Gardens|Botanic Gardens]] is considered by some to be among the finest collections of orchids in cultivation open to the public. In [[2004]], [[Taiwan]] established the [[Taiwan Orchid Plantation]], a science-based [[industrial park]], to develop its commercial orchid exports in the future. See also [[botanical orchids]].

Orchids, like [[tulip]]s, have become a major market throughout the world. Buyers now bid hundreds of dollars on new hybrids or improved ones. Because of their apparent ease in hybridization, they are now becoming one of the most popular cut-flowers on the market. Though orchid hybridization has been happening for many years, only recently has new technology made it into what it is.

==Vanilla==
[[Image:Vanilla fragrans 2.jpg|thumb|250px|Vanilla fruit]]

[[Vanilla]], ''Vanilla planifolia'' (and two other ''Vanilla'' species less commonly grown), is the only orchid which is grown for any other use besides its beauty (with a few minor exceptions). Vanilla was first cultivated in [[Central America]] where it was used, like today, as a flavoring. Vanilla cultivation was introduced to other parts of the world in the 1800s and it is now an important crop in much of the tropics. [[Madagascar]] is the leading producer, producing in 2005, 3 million metric tons (of a world total of 7.3 million metric tons).

The [[Coca-Cola]] Company is the world's largest user of vanilla. Besides its use as a flavoring, it is also used in fragrances and perfumes.

Vanilla is a very labor intensive crop since the flowers have to be pollinated by hand. It is considered as one of the most profitable enterprises for small family farms. [http://news.bbc.co.uk/1/hi/business/3017876.stm]

==Taxonomy==
The taxonomy of this family is in constant flux, as [[DNA]] studies give new information. An in-depth treatment of the taxonomy is given in [[Taxonomy of the Orchid family]].

The following genera have been described (for a full list, see [[List of Orchidaceae genera]] with more than 800 genera and many pictures):

''[[Aa (plant)|Aa]]'';
''[[Abdominea]]'';
''[[Acampe]]'';
''[[Acanthephippium]]'';
''[[Aceratorchis]]'';
''[[Acianthus]]'';
''[[Acineta]]'';
''[[Acrorchis]]'';
''[[Ada (orchid)|Ada]]'';
''[[Aerangis]]'';
''[[Aeranthes]]'';
''[[Aerides]]'';
''[[Aganisia]]'';
''[[Agrostophyllum]]'';
''[[Amitostigma]]'';
''[[Anacamptis]]'';
''[[Ancistrochilus]]'';
''[[Angraecum]]'';
''[[Anguloa]]'';
''[[Ansellia]]'';
''[[Aorchis]]'';
''[[Aplectrum]]'';
''[[Arethusa (plant)|Arethusa]]'';
''[[Armodorum]]'';
''[[Ascocenda]]'';
''[[Ascocentrum]]'';
''[[Ascoglossum]]'';
''[[Australorchis]]'';
''[[Auxopus]]'';
''[[Baptistonia]]'';
''[[Barbrodia]]'';
''[[Barkeria]]'';
''[[Barlia]]'';
''[[Bartholina]]'';
''[[Beloglottis]]'';
''[[Biermannia]]'';
''[[Bletilla]]'';
''[[Brassavola]]'';
''[[Brassia]]'';
''[[Bulbophyllum]]'';
''[[Calypso Orchid|Calypso]]'';
''[[Catasetum]]'';
''[[Cattleya]]'';
''[[Cirrhopetalum]]'';
''[[Cleisostoma]]'';
''[[Clowesia]]'';
''[[Coelogyne]]'';
''[[Coryanthes]]'';
''[[Cymbidium]]'';
''[[Cyrtopodium]]'';
''[[Cypripedium]]'';
''[[Dactylorhiza]]'';
''[[Dendrobium]]'';
''[[Disa (orchid)|Disa]]'';
''[[Dracula (biology)|Dracula]]'';
''[[Encyclia]]'';
''[[Epidendrum]]'';
''[[Epipactis]]'';
''[[Eria]]'';
''[[Eulophia]]'';
''[[Gongora]]'';
''[[Goodyera]]'';
''[[Grammatophyllum]]'';
''[[Gymnadenia]]'';
''[[Habenaria]]'';
''[[Herschelia]]'';
''[[Laelia]]'';
''[[Lepanthes]]'';
''[[Liparis]]'';
''[[Ludisia]]'';
''[[Lycaste]]'';
''[[Masdevallia]]'';
''[[Maxillaria]]'';
''[[Mexipedium]]'';
''[[Miltonia]]'';
''[[Mormodes]]'';
''[[Odontoglossum]]'';
''[[Oncidium]]'';
''[[Ophrys]]'';
''[[Orchis]]'';
''[[Paphiopedilum]]'';
''[[Paraphalaenopsis]]'';
''[[Peristeria]]'';
''[[Phaius]]'';
''[[Phalaenopsis]]'';
''[[Pholidota (orchid)|Pholidota]]'';
''[[Phragmipedium]]'';
''[[Platanthera]]'';
''[[Pleione (orchid)|Pleione]]'';
''[[Pleurothallis]]'';
''[[Promenaea]]'';
''[[Pterostylis]]'';
''[[Renanthera]]'';
''[[Renantherella]]'';
''[[Restrepia]]'';
''[[Restrepiella]]'';
''[[Rhynchostylis]]'';
''[[Saccolabium]]'';
''[[Sarcochilus]]'
';
''[[Satyrium]]'';
''[[Selenipedium]]'';
''[[Serapias]]'';
''[[Sophronitis]]'';
''[[Spiranthes]]'';
''[[Stanhopea]]'';
''[[Stelis]]'';
''[[Thrixspermum]]'';
''[[Trias]]'';
''[[Trichocentrum]]'';
''[[Trichoglottis]]'';
''[[Vanda]]'';
''[[Vanilla (orchid)|Vanilla]]'';
''[[Zeuxine]]'';
''[[Zygopetalum]]''.

==See also==
*[[Moyobamba]] - the 'City of Orchids', which has some 3,500 species of orchid native to the area
*[[Semi-hydroponic for growing orchids]]

==References==

*Batygina, T. B., Bragina, E. A., and Vasilyeva, E. 2003. ''The reproductive system and germination in orchids''. Acta Biol. Cracov. ser. Bot. 45: 21-34.
*Berg Pana, H. 2005. ''Handbuch der Orchideen-Namen. Dictionary of Orchid Names. Dizionario dei nomi delle orchidee''. Ulmer, Stuttgart
*Kreutz, C. A. J. 2004. ''Kompendium der Europaischen Orchideen. Catalogue of European Orchids''. Kreutz Publishers, Landgraaf, Netherlands
* D. Lee Taylor and Thomas D. Bruns : ''Ectomycorrhizal mutualism by two nonphotosynthetic orchids''; Proc. Natl. Acad. Sci. USA; Vol. 94, pp. 4510-4515, April 1997 ([http://plantbio.berkeley.edu/~bruns/papers/taylor1997b.html on line]).

==External links==
*[http://www.anbg.gov.au/cpbr/orchids/index.html Revealing the secret life of orchids ( Centre for plant biodiversity research - CSIRO and Botanic Gardens Australia )]
*[http://www.apstas.com/groundorchids.htm Tasmanian terrestrial orchids (Hobart District Group of The Australian Plants Society)]
{{commonscat|Orchidaceae}}
*[http://www.kew.org/wcsp/home.do Kew checklist]
* [http://www.digitalcloseups.com Orchid Picture Gallery]
*[http://www.ocos.net Orange County (California) Orchid Society]
*[http://www.orchidspecies.com/index.htm Orchid Photo Encyclopedia]
*[http://news.nationalgeographic.com/news/2004/03/0308_040308_cheatingorchids.html#main Report on pollination tactics by orchids]
*[http://www.orchideen.at/english/frames_e.htm Austrian Orchid Society]
*[http://www.orchidean.com/videos Orchid Videos]
*[http://www.orchidworks.com/ OrchidWorks] - a photo album and overview of a variety of orchids
*[http://orchid.unibas.ch/ Swiss Orchid Foundation at the Herbarium Jany Renz]
*[http://www.nativeorchid.org/ Native Orchid Conservation Inc]
*[http://www.pharmanatur.com/orchid.htm Orchids of Europe]
*[http://www.mayumihashi.com/blog-en/ Peruvian Orchids] - Mayumi Hashi, a botanical illustrator's report on a trip to Peru, which was partly funded by the [[Royal Horticultural Society]] (RHS).
*[http://www.fieldmuseum.org/vanishing_treasures/V_Wwaling.htm Waling-waling, an endangered orchid]
*[http://www.coloridellamurgia.it/gall/schedebotorc/index.htm Wild orchids of "Alta Murgia" (Apulia - Southern Italy)]
*[http://www.alpine-plants-jp.com/art/index_ranka.htm Wild orchid of Japan] - Flavon's art gallery

[[Category:Flowers]]
[[Category:Plant families]]
[[Category:Orchids| ]]

@@ Line 246: / Line 246: @@
 Where closed pots are used , nearly one-half of the space should be devoted to drainage and the remainder to compost, consisting of about equal parts of peat fiber, chopped sphagnum and leaf-mold for most genera, adding a few pieces of charcoal in potting, and a piece beneath the rhizome of the tender ones. Care must be exercised in potting to distribute the roots properly and make the compost moderately firm about them, leaving the finished surface convex, to throw off surplus water and protect the rhizome from an overabundance of wet. Top-dressing with live sphagnum is beneficial to many orchids, such as Odonioglossum crispum and allies, and gives the surface a neat appearance. Fig. 2668 illustrates a finished pot, the dotted line in Fig. 2666 indicating the amount of drainage required.
- When perforated or open-work pots or baskets are employed, no direct drainage is necessary. Rough, broken pieces of charcoal should be freely used in the compost while potting, as it helps to keep the mass firm and the roots of nearly all species attach to it freely; also it lessens the quantity of compost and so modifies its texture as to allow it to dry out more readily than when packed in a solid body.
+When perforated or open-work pots or baskets are employed, no direct drainage is necessary. Rough, broken pieces of charcoal should be freely used in the compost while potting, as it helps to keep the mass firm and the roots of nearly all species attach to it freely; also it lessens the quantity of compost and so modifies its texture as to allow it to dry out more readily than when packed in a solid body.
 Cattleyas of the C. intermedia type, coryanthes, cypripediums of the C. Lowei and C. Stonei sections, some dendrobiums, Oncidium carthaginense, O. crispum, O. macranthum, 0. Papilio and their allies should have the leaf-mold omitted, while aerides, phalaenopsis, saccolabiums, vandas and kindred genera require only chopped live sphagnum and charcoal as a compost.
@@ Line 357: / Line 357: @@
- It is often said that orchids need a well-marked period of rest. This is not always possible with specimens newly received from the wilds, as the flowering period has to be changed to accord with our winter or summer which in time governs their well-being. We will assume that the flowers have been pollinated by insect agency, and the seeds have matured. This maturation usually requires about a year. No one knows the number of seeds that will be contained in a healthy capsule. There must be tens of thousands, a very small proportion of which ever reach maturity when sown under glass; but here is apparently a reason for the time taken to ripen the capsule, that it may take place about the period for the plants to bloom again, which is presumably the most favorable or rainy season, and the seeds are distributed by the breeze to suitable media, and a proportion germinates and grows. We learn by sowing under glass that very few, even under the most careful treatment, ever live through the vicissitudes of initial stages, the tiny green globes or thalli having no true roots for months. It is perhaps a year after sowing the seeds before true roots are visible, but in the mean- tune, a hot drying day, if no gentle spraying of moisture is given, will blast all the hopes of many months' waiting: but we have the compensation of knowing that each plant we raise will be eminently fitted to survive under greenhouse conditions. The recent careful laboratory investigations have suggested rational methods of procedure in the growing of seedlings, and the subject will probably gradually pass out of the region of accident and doubt. (See page 2387.)
+It is often said that orchids need a well-marked period of rest. This is not always possible with specimens newly received from the wilds, as the flowering period has to be changed to accord with our winter or summer which in time governs their well-being. We will assume that the flowers have been pollinated by insect agency, and the seeds have matured. This maturation usually requires about a year. No one knows the number of seeds that will be contained in a healthy capsule. There must be tens of thousands, a very small proportion of which ever reach maturity when sown under glass; but here is apparently a reason for the time taken to ripen the capsule, that it may take place about the period for the plants to bloom again, which is presumably the most favorable or rainy season, and the seeds are distributed by the breeze to suitable media, and a proportion germinates and grows. We learn by sowing under glass that very few, even under the most careful treatment, ever live through the vicissitudes of initial stages, the tiny green globes or thalli having no true roots for months. It is perhaps a year after sowing the seeds before true roots are visible, but in the mean- tune, a hot drying day, if no gentle spraying of moisture is given, will blast all the hopes of many months' waiting: but we have the compensation of knowing that each plant we raise will be eminently fitted to survive under greenhouse conditions. The recent careful laboratory investigations have suggested rational methods of procedure in the growing of seedlings, and the subject will probably gradually pass out of the region of accident and doubt. (See page 2387.)
 Variation that obtains among wild orchids is also present in various degrees among crosses and hybrids raised under cultivation. This was proved by the raising of over eighty plants of Cattteya Thayeriana, no two of which were alike, and some could not have been attributed to the same origin were it not for the connecting-links that rounded out the series.

← Older revision		Revision as of 14:13, 23 February 2010
Line 282:		Line 282:


−	The pseudobulbous species, such as cattleyas, odontoglossums, coelogynes, are propagated by cutting part way through the rhizome three or more pseudobulbs behind the lead with a sharp knife. This will usually retard the sap and force the dormant eye behind the cut to grow. The back portion may then be removed and potted or basketed separately, or left on the plant to mature the new growth, and be removed when it starts action the following season.	+	The pseudobulbous species, such as cattleyas, odontoglossums, coelogynes, are propagated by cutting part way through the rhizome three or more pseudobulbs behind the lead with a sharp knife. This will usually retard the sap and force the dormant eye behind the cut to grow. The back portion may then be removed and potted or basketed separately, or left on the plant to mature the new growth, and be removed when it starts action the following season.

	With the deciduous calanthes, the old bulbs should be removed when potting them in spring and put, several together, in pans or flats and partly covered with sphagnum or potting compost until they start to grow, when they should be potted in the regular way. Thunias are easily propagated after the young growths are well advanced, by cutting the last year's stems into pieces 4 or 5 inches long and inserting the ends hi chopped sphagnum and sand, placing them in the propagating-house until they grow, when they may have their normal heat. Dendrobiums are managed in much the same way, or the old canes can be laid on wet sphagnum, when many will produce new growths from the side eyes on the nodes. Aerides and vandas are increased by removing the upper portion with a sharp knife, leaving a few roots and at least a foot of stem to each top. The old bases of the stems usually break new growths freely, often producing several new shoots from each. Cypripediums should be divided between the older growths, leaving at least one old growth with each lead; and potted separately, allowing them a little extra moisture until they start to grow. Masdevallias and allied genera can be separated in the same manner, leaving several leaves and one or more new growths or leads to each piece. All species should be propagated at the commencement of the growing season.		With the deciduous calanthes, the old bulbs should be removed when potting them in spring and put, several together, in pans or flats and partly covered with sphagnum or potting compost until they start to grow, when they should be potted in the regular way. Thunias are easily propagated after the young growths are well advanced, by cutting the last year's stems into pieces 4 or 5 inches long and inserting the ends hi chopped sphagnum and sand, placing them in the propagating-house until they grow, when they may have their normal heat. Dendrobiums are managed in much the same way, or the old canes can be laid on wet sphagnum, when many will produce new growths from the side eyes on the nodes. Aerides and vandas are increased by removing the upper portion with a sharp knife, leaving a few roots and at least a foot of stem to each top. The old bases of the stems usually break new growths freely, often producing several new shoots from each. Cypripediums should be divided between the older growths, leaving at least one old growth with each lead; and potted separately, allowing them a little extra moisture until they start to grow. Masdevallias and allied genera can be separated in the same manner, leaving several leaves and one or more new growths or leads to each piece. All species should be propagated at the commencement of the growing season.

@@ Line 54: / Line 54: @@
 ==Leaves==
 [[image:Dendrobium crumenatum.jpg|thumb|250px|right|This small orchid demonstrates a typical [[zygomorphic]] flower with three petal-like [[sepal]]s (top, lower right, lower left), two normal [[petal]]s on either side of the dorsal (upper) sepal, and  the [[labellum]], a modified lower petal in three parts surrounding and below the shiny column.]]
 Orchids have simple [[Leaf|leaves]] with parallel [[vein]]s. Their shape is highly variable between species; ovate, lanceolate, or orbiculate. Their size and shape can be an aid in identifying the orchid, since it reflects the taxonomic position. The leaves can be enormous or minute, or they can even be lacking (as in the [[Ghost Orchid]] (''Dendrophylax lindenii''), a mycoheterotrophic species, and ''[[Aphyllorchis]]'' and ''[[Taeniophyllum]]'', which depend on their roots, which contain chlorophyll for [[photosynthesis]]).
@@ Line 60: / Line 59: @@
 The structure of the leaves corresponds to the specific habitat of the orchid. Species that typically bask in sunlight, or grow on sites which can be occasionally very dry, have thick, leathery leaves. The [[lamina]]s are covered by a waxy [[cuticle]]. These retain their necessary water supply. Shade species, on the other hand, have tall, thin leaves. They cannot tolerate a drop in atmospheric humidity or exposure to direct sunlight. Between these two extremes, there is a whole range of intermediate forms.
-The leaves of most orchids live on, attached to their [[pseudobulbs]], for several years. Some species, especially those with plicate leaves, shed their aged leaves annually, through an articulation between the lamina and the [[Petiole (botany)|petiole]] sheath, and develop new leaves together with
+The leaves of most orchids live on, attached to their [[pseudobulbs]], for several years. Some species, especially those with plicate leaves, shed their aged leaves annually, through an articulation between the lamina and the [[Petiole (botany)|petiole]] sheath, and develop new leaves together with new pseudobulbs (as in the genus ''[[Catasetum]]'').
 The leaves of some species can be most beautiful. The leaves of the ''Macodes sanderiana'', a semiterrestrial or lithophyte, show a sparkling silver and gold veining on a light green background. The cordate leaves of ''Psychopsiella limminghei'' are light brownish green with maroon-puce markings, created by flower pigments. The attractive mottle of the leaves of [[Lady's Slipper]]s from temperate zones (''[[Paphiopedilum]]'') is caused by uneven distribution of chlorophyll. Also ''Phalaenopsis schilleriana'' is a lovely 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 fairly inconspicuous white flowers.
@@ Line 71: / Line 69: @@
 ==Plant thallus and roots==
 [[image:Pseudobulbs_new.jpg|thumb|right|[[Pseudobulb]]s of an [[epiphytic]] orchid]]
 All orchids are [[perennial]] herbs, lacking any permanent [[wood]]y structure.
@@ Line 78: / Line 75: @@
 *Several species are [[lithophyte]]s, especially in rocky mountain ranges in [[Australia]] and [[Tasmania]], central [[Brazil]] and [[Africa]].
-The base of the stem of sympodial epiphytes, or in some species essentially the entire stem, may be thickened to form what is called a ''',[[pseudobulb]]'''. These contain nutrients and water for drier periods. Pseudobulbs have a smooth surface with lengthwise grooves. They typically stay alive for five or six years. They look on the inside more like a corm than the embryonal stage of leaf sheaths. They have different sizes and shapes. They can be conical or oblong. In the Black Orchids (''[[Bulbophyllum]]''), the pseudobulbs are no longer than 2&nbsp;mm. The largest orchid in the world, the [[Giant Orchid]] (''Grammatophyllum speciosum''), has pseudobulbs with lengths of 2&ndash;3&nbsp;m. When the orchid has aged and the pseudobulb has shed its leaves, the pseudobulb becomes dormant and is called
+The base of the stem of sympodial epiphytes, or in some species essentially the entire stem, may be thickened to form what is called a ''',[[pseudobulb]]'''. These contain nutrients and water for drier periods. Pseudobulbs have a smooth surface with lengthwise grooves. They typically stay alive for five or six years. They look on the inside more like a corm than the embryonal stage of leaf sheaths. They have different sizes and shapes. They can be conical or oblong. In the Black Orchids (''[[Bulbophyllum]]''), the pseudobulbs are no longer than 2&nbsp;mm. The largest orchid in the world, the [[Giant Orchid]] (''Grammatophyllum speciosum''), has pseudobulbs with lengths of 2&ndash;3&nbsp;m. When the orchid has aged and the pseudobulb has shed its leaves, the pseudobulb becomes dormant and is called a '''backbulb'''. The next year's pseudobulb then takes over, exploiting the last reserves of the backbulb. Eventually, the backbulb also dies off, having given life to newer growths. At the end of the pseudobulb typically appear one or two leaves, though there may be up to a dozen or more. Some ''[[Dendrobium]]'' have long, canelike pseudobulbs with short, rounded leaves over the whole length. Some orchids have hidden or extremely small pseudobulbs hidden completely inside leaves.
 Some sympodial terrestrials, such as ''Orchis'' and ''[[Ophrys]]'', have two subterranean tubers (more like [[tuberous root]]s) between the [[root]]s. One is used as a food reserve for wintery periods, and provides for the development of the other pseudobulb, from which visible growth develops.
@@ Line 103: / Line 99: @@
 Sepals form the exterior of the bud. They are green in this stage, but sometimes, if the orchid blossom is, for example, purple, the buds can show a purple tint. When the flower opens, the sepals become intensely colored. Sepals may mimic petals such as in some phalaenopsis or be completely distinct. In many orchids, the sepals are mutually different and generally resemble the petals. It is not always easy to distinguish sepals and petals. The normal form can be found in ''[[Cattleya]]'', with three sepals forming a triangle. But in Venus Slippers (''Paphiopedilum'') the lower two sepals are concrescent (fused together into a [[synsepal]]), while the lip has taken the form of a slipper. In ''[[Masdevallia]]'' all the sepals are fused into a [[calyx (flower)|calyx]]. In an example like this the sepals are very prominent, especially in lycaste orchids, the actual petals become diminished and inconspicuous.
-The [[reproductive organ]]s in the center ([[stamen]]s and [[carpel|pistil]]) have adapted to become a cylindrical structure called the [[column (botany)|column]] or gynandrium. On top of the column lies the [[Carpel|stigma]], the vestiges of stamens and the [[Pollinium|pollinia]], a mass of waxy [[pollen]] on filaments. These filaments can be a '''[[caudicle]]''' (as in ''[[Habenaria]]'') or a '''[[stipe (botany)|stipe]]''' (as in ''[[Vanda]]''). These filaments hold the pollinia to the '''[[viscidium]]''' (sticky pad). The pollen are held together by the [[alkaloid]] [[viscine]]. This viscidium adheres to the body of a visiting insect. The type of pollinia is useful in determining the genus. On top of the pollinia is the '''[[anther cap]]''', preventing self-pollination. At the upper edge of the stigma of single-anthered orchids,
+The [[reproductive organ]]s in the center ([[stamen]]s and [[carpel|pistil]]) have adapted to become a cylindrical structure called the [[column (botany)|column]] or gynandrium. On top of the column lies the [[Carpel|stigma]], the vestiges of stamens and the [[Pollinium|pollinia]], a mass of waxy [[pollen]] on filaments. These filaments can be a '''[[caudicle]]''' (as in ''[[Habenaria]]'') or a '''[[stipe (botany)|stipe]]''' (as in ''[[Vanda]]''). These filaments hold the pollinia to the '''[[viscidium]]''' (sticky pad). The pollen are held together by the [[alkaloid]] [[viscine]]. This viscidium adheres to the body of a visiting insect. The type of pollinia is useful in determining the genus. On top of the pollinia is the '''[[anther cap]]''', preventing self-pollination. At the upper edge of the stigma of single-anthered orchids, in front of the anther cap, is the '''[[rostellum]]''', a slender beaklike extension.
 ==Reproduction==
@@ Line 122: / Line 117: @@
 ==Fruits and seeds==
 [[Image:Kapselquerschnitte Orchideen.png|thumb|right|200px|cross-section of an orchid capsule, showing 3 or 6 longitudinal slits]]
-The orchid [[ovary (plants)|ovary]] is always inferior (located behind the flower), three-[[carpel]]ate and one or three-partitioned, with parietal [[placenta]]tion (but axile in the [[Apostasioidea
+The orchid [[ovary (plants)|ovary]] is always inferior (located behind the flower), three-[[carpel]]ate and one or three-partitioned, with parietal [[placenta]]tion (but axile in the [[Apostasioideae]]).
 If pollination was successful, the sepals and petals fade and wilt but they remain attached to the ovary. The epigynous ovary typically develops into a [[capsule (fruit)|capsule]] that is [[dehiscent]] by 3 or 6 longitudinal slits, while remaining closed at both ends. The [[ripe]]ning of a capsule can take 2&ndash;18 months. The microscopic [[seed]]s are very numerous (over a million per capsule in most species). They blow off after ripening like dust particles or spores, barely visible to the human eye. Since they lack [[endosperm]], they must enter symbiotic relationship with mycorrhizal fungi to germinate. These fungi provide the necessary nutrients to the seeds.
@@ Line 146: / Line 140: @@
 ==Vanilla==
- [[Image:Vanilla fragrans 2.jpg|thumb|250px|Vanilla fruit]]
+[[Image:Vanilla fragrans 2.jpg|thumb|250px|Vanilla fruit]]
 [[Vanilla]], ''Vanilla planifolia'' (and two other ''Vanilla'' species less commonly grown), is the only orchid which is grown for any other use besides its beauty (with a few minor exceptions).   Vanilla was first cultivated in [[Central America]] where it was used, like today, as a flavoring.  Vanilla cultivation was introduced to other parts of the world in the 1800s and it is now an important crop in much of the tropics.  [[Madagascar]] is the leading producer, producing in 2005, 3 million metric tons (of a world total of 7.3 million metric tons).