''Oncidium'', abbreviated as Onc. in the horticultural trade, is a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
that, , contains about 340
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
orchid
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan plants that are found in almost every habitat on Eart ...
s from the subtribe
Oncidiinae
The Oncidiinae is a subtribe within the Orchidaceae that consists of a number of genera that are closely related.
This subtribe consists of about 70 genera with over 1000 species, with ''Oncidium'' as its largest genus. These genera consist of a ...
of the orchid family Orchidaceae. It is distributed across tropical and subtropical America from
Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
,
Central America
Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...
and the
West Indies
The West Indies is an island subregion of the Americas, surrounded by the Atlantic Ocean, North Atlantic Ocean and the Caribbean Sea, which comprises 13 independent island country, island countries and 19 dependent territory, dependencies in thr ...
to northern
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
, with one species (''O. ensatum'') extending into Florida. Common names for plants in this genus include dancing-lady orchid and golden shower orchid.
A 2008
molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
study labeled the ''Oncidium'' alliance "grossly
polyphyletic
A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...
." In the same year, the American Orchid Society labeled the genus a "dumping ground".Lindleyana : The scientific journal of the American Orchid Society. December 2008 Pg 20 A consensus announced in April 2013 resulted in major taxonomic changes to ''Oncidium'', ''
Gomesa
''Gomesa'' is a genus of flowering plants from the orchid family, Orchidaceae. It contains about 80–100 species, all native to South America. The genus is abbreviated as ''Gom''.Odontoglossum
''Odontoglossum'', first named in 1816 by Karl Sigismund Kunth, is a formerly accepted genus of orchids that is now regarded as a synonym of '' Oncidium''. Several hundred species have previously been placed in ''Odontoglossum''. The scientific ...
'', ''
Miltonia
''Miltonia'', abbreviated Milt. in the horticultural trade, is an orchid genus comprising twelve epiphyte species and eight natural hybrids. The miltonias are exclusively inhabitants of Brazil, except for one species whose range extends from Braz ...
'', and others. Much of this debate and subsequent housekeeping was initiated by significant research for the scientific publication ''Genera Orchidacearum'' Volume 5. As a result, much of the information in this article is now
deprecated
Deprecation is the discouragement of use of something human-made, such as a term, feature, design, or practice. Typically something is deprecated because it is claimed to be inferior compared to other options available.
Something may be deprec ...
, but still of great value. One significant change is the move of most Brazilian ''Oncidium'' with a fused lateral sepal to the genus ''
Gomesa
''Gomesa'' is a genus of flowering plants from the orchid family, Orchidaceae. It contains about 80–100 species, all native to South America. The genus is abbreviated as ''Gom''.Olof Swartz
Olof Peter Swartz (21 September 1760 – 19 September 1818) was a Swedish botanist and taxonomist. He is best known for his taxonomic work and studies into pteridophytes, but also studied orchids, mosses and lichens.
Biography
Olof Swartz a ...
in 1800 with the orchid ''Oncidium altissimum'', which has become the type species. Its name is derived from the Greek word ὀγκος, ''onkos'', meaning "swelling". This refers to the callus at the lower lip.
Most species in the genus are
epiphytes
An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...
(growing on other plants), although some are
lithophyte
Lithophytes are plants that grow in or on rocks. They can be classified as either epilithic (or epipetric) or endolithic; epilithic lithophytes grow on the surfaces of rocks, while endolithic lithophytes grow in the crevices of rocks (and are als ...
s (growing on rocks) or terrestrials (growing in soil). They are widespread from northern
Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
, the
Caribbean
The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...
, and some parts of South
Florida
Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...
to South America. They usually occur in seasonally dry areas.
They can be divided into three categories, according to their growth pattern:
* Some have green
pseudobulb
In botany, a 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 ''heter ...
s and long
raceme
A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...
s with small flowers and a dominant
lip
The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...
. They are mostly golden yellow with or without reddish-brown barring, but some are brown or yellowish-brown. Other ''Oncidium'' species have white and pink blooms, while some even have startling, deep red colors in their flowers.
* Another group has extremely small pseudobulbs and stiff, erect, solitary
leaves
A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...
. These cylindrical leaves act as a water reserve. They have long racemes with yellow flowers that seem to fan out at the top. Sizes of these orchids can vary from miniature plants of a couple of centimetres to giants with 30 cm-long leaves and racemes of more than one metre long. These species, known as the Mule-Ears, are now classed as ''
Psychopsis
''Psychopsis'' is a genus of four known species of orchids native to northern South America, Central America and Trinidad. The genus name is abbreviated ''Pyp.'' in the horticultural trade.
Description
''Psychopsis'' are epiphytic orchids with ...
''.
* Formerly there was a third group, called the Variegata or equitant oncidiums. They have no pseudobulbs, giving fan-shaped shoots of less than 15 cm, with triangular section leaves. These oval, broad and spongy leaves act as storage organs. Their flowers are most complicated with exquisite colors. The sepals are somewhat fleshy. The petals and the lip are membranaceous. These orchids are now classified as '' Tolumnia''. ''Cyrtochilum'' is another
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
that many ''Oncidium'' species have been reclassified into; ''Cyrtochilum'' species have extremely long, winding inflorescences that can sometimes reach 20' or more, curled petals that result in three-pointed blooms, and rambling growth habits in which each new pseudobulb appears on top of the old one.
''Oncidium'' species are characterised by the following properties :
* presence of
column
A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member ...
wings,
* presence of a complicated callus on the
lip
The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...
(this can be used to separate the taxa),
*
pseudobulb
In botany, a 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 ''heter ...
s with one to three leaves,
* several basal
bract
In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale.
Bracts are usually different from foliage leaves in size, color, shape or texture. They also lo ...
s at the base of the pseudobulbs.
The
flower
Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...
s come in shades of yellow, red, white and pink. The petals are often ruffled on the edges, as is the
lip
The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...
. The lip is enormous, partially blocking the small petals and sepals.
Some ''Oncidium'' orchids are very tall: ''
Oncidium altissimum
''Oncidium altissimum'', Wydler's dancing-lady orchid, is a species of orchid native to the West Indies (Cuba, Puerto Rico and the Lesser Antilles), with an 18th-Century citation from Jamaica.
This name should not be confused with the illegitim ...
'' and ''
Oncidium baueri
''Oncidium baueri'' is a species of orchid native to Costa Rica and to South America as far south as Bolivia and Brazil
Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of ...
'' can grow to a height of 5 m.
They are known as 'spray orchids' among some florists. They are very varied and are easily hybridised with other closely related genera forming the ''Oncidium'' alliance (''Miltonia'', '' Cuitlauzina'', '' Miltoniopsis'', '' Leochilus'', '' Comparettia'', ''
Cyrtochilum
''Cyrtochilum'' is a genus of flowering plant in the family Orchidaceae, native to the Caribbean and to South America from Costa Rica to Peru. The genus was established by Carl Sigismund Kunth in 1978.
Species
, Plants of the World Online
P ...
'', '' Tolumnia'', '' Rhynchostele'' ormerly ''Lemboglossum'' ''Psychopsis'', etc.). Some of the best ''Oncidium'' alliance hybrids originate from '' Oncidium tigrinum'' and '' Oncidium incurvum'' when crossed with species formerly placed in ''Odontoglossum'', although hybridization possibilities of this group of orchids are endless, and there are literally hundreds of thousands of hybrids in the ''Oncidium'' alliance.
Selected species
Selected species accepted by Plants of the World Online :
*''
Oncidium altissimum
''Oncidium altissimum'', Wydler's dancing-lady orchid, is a species of orchid native to the West Indies (Cuba, Puerto Rico and the Lesser Antilles), with an 18th-Century citation from Jamaica.
This name should not be confused with the illegitim ...
Oncidium baueri
''Oncidium baueri'' is a species of orchid native to Costa Rica and to South America as far south as Bolivia and Brazil
Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of ...
Oncidium sphacelatum
''Oncidium sphacelatum'' is a species of orchid ranging from Mexico to Central America and southeastern Venezuela. It is known as Kandyan dancer orchid in Sri Lanka due to its resemblance to a Kandyan dance
Kandyan dance (Sinhala language, Si ...
'' (Mexico to C. America, SE. Venezuela)
*'' Oncidium strictum'' (Cogn.) M.W.Chase & N.H.Williams (Ecuador, Peru)
*'' Oncidium wentworthianum'' (Mexico – Chiapas to El Salvador)
Gomesa ciliata
''Gomesa'' is a genus of flowering plants from the orchid family, Orchidaceae. It contains about 80–100 species, all native to South America. The genus is abbreviated as ''Gom''.Oncidium concolor'' → ''
Gomesa concolor
''Gomesa'' is a genus of flowering plants from the orchid family, Orchidaceae. It contains about 80–100 species, all native to South America. The genus is abbreviated as ''Gom''.'' Oncidium cornigerum'' → ''
Many hybrids have been created artificially involving species of ''Oncidium'', often with species of other genera. Named hybrid genera (nothogenera) are listed in the table below, together with their parent genera. , ''Cochlioda'' and ''Odontoglossum'' are included within ''Oncidium'', and ''Baptistonia'' within ''Gomesa'', so that nothogenus names which include these three genera are redundant.
References
* Harry Zelenko :The Pictorial Encyclopaedia of Oncidium (1997)
* Koniger, W. 2003. New species of the genera Masdevallia, Oncidium and Sigmatostalix. Arcula no. 12: 298–311.
*