View source for Bifrenaria

{{Short description|Genus of orchids}}
{{Automatic taxobox
| image = Bifrenaria tyrianthina Orchi 01.jpg
| image_caption = ''Bifrenaria tyrianthina''
| display_parents = 3
| taxon = Bifrenaria
| authority = [[John Lindley|Lindl..]]
| type_species = ''[[Bifrenaria atropurpurea]]''
| type_species_authority = [[Lindl.]]
| synonyms_ref = <ref name="WCSP">{{WCSP | 22037 | ''Bifrenaria'' }}</ref>
| synonyms =
* ''Colax'' {{small|[[Lindl.]] ex [[Spreng.]]}}
* ''Adipe'' {{small|[[Constantine Samuel Rafinesque|Raf.]]}}
* ''Stenocoryne'' {{small|[[Lindl.]]}}
* ''Cydoniorchis'' {{small|[[Senghas]]}}
| range_map = Bifrenaria distribution map.png
| range_map_caption = Distribution of ''Bifrenaria''
| subdivision_ranks = Species
| subdivision =
see text
}}

'''''Bifrenaria''''', abbreviated '''Bif.''' in horticultural trade, is a genus of [[plant]]s in family [[Orchidaceae]]. It contains  20 species found in [[Panama]], [[Trinidad]] and [[South America]]. There are no known uses for them, but their abundant, and at first glance artificial, [[flower]]s, make them favorites of orchid growers.

The genus can be split in two clearly distinct groups:<ref name="Cogn">Cogniaux, Celestin A.(1902). ''Bifrenaria'' in Flora Brasiliensis K.F.P.von Martius & auct. suc. (eds.) vol.3 p. 5: 476. [http://florabrasiliensis.cria.org.br/search?taxon_id=237 published on Internet.]</ref> one of highly robust plants with large flowers, that encompass the first species to be classified under the genus ''Bifrenaria''; other of more delicate plants with smaller flowers occasionally classified as ''Stenocoryne'' or ''Adipe''. There are two additional species that are normally classified as ''Bifrenaria'', but which molecular analysis indicate to belong to different orchid groups entirely. One is ''Bifrenaria grandis'' which is endemic to [[Bolívia]] and which is now placed in ''[[Lacaena]]'',<ref>Kraenzlin, Friedrich Wilhelm Ludwig (1928). While ''Lacaena grandis'' in Repertorium specierum novarum regni vegetabilis. Ed. Selbstverlag des Herausgebers, Berlin, at vol.25: 25.</ref> and ''[[Bifrenaria steyermarkii]]'', an inhabitant of the northern [[Amazon Forest]],<ref>Dunsterville, Galfried Clement Keyworth & Garay, Leslie A. (1976). ''Bifrenaria steyermarkii'' in Venezuelan Orchids Illustrated vol.6: 56. London.</ref> which does not have an alternative classification.

==Description==
[[Image:Bifrenaria tyrianthina plant.jpg|thumb|left|''[[Bifrenaria tyrianthina]]'' showing the prominent [[banana]]-like pseudobulbs of larger species.]]
[[Image:Bifrenaria silvana.jpg|thumb|left|By contrast, the pseudobulbs of smaller species, such as this ''[[Bifrenaria racemosa]]'', a much less noticeable.]]

''Bifrenaria'' are generally robust plants, of [[sympodial]] growth, between ten and sixty centimeters tall. They are characterized by round-section root with thick [[velamen]], four-angled fleshy [[pseudobulb]]s of one internode, often basally protected by dried sheaths and with only one apical [[leaf]] (except for ''Bifrenaria steyermarkii'', which occasionally has two),<ref>Foldats, Ernesto (1970). ''Xylobium steyermarkii'' em Novedades Cientificas, Contribuciones Occasionales del Museo de Historia Natural La Salle vol.35: 1. Serie Botanica. Caracas.</ref> plicate (fan-folded) enervated leathery leaves, yet malleable and not exceedingly thick, with a pseudo-petiole of basal round section, and a basal [[inflorescence]]s bearing up to ten flowers, which seldom surpass the leaves' length.<ref name="FB"/>

''Bifrenaria'' flowers are strongly scented, they have sepals slightly larger than the petals, with the lateral ones basally united to the [[column (botany)|column]] foot forming a [[calcar]] with truncated extremity. The column is slightly arching, generally without wings or any other appendages, bearing a foot  which the labellum is hinged to, whose shape varies, articulated to the column, with a longitudinal channeled callus often with a basal claw. Flowers show two elongated [[stipe (botany)|stipe]]s, hardy ever one, at least twice longer than wide, with salient [[viscidium]], visible [[caudicle]]s and [[retinacle]]{{typo help inline|date=July 2020}} in inverted positions. The superposed [[pollinia]] number four, and are protected by a deciduous incumbent [[anther]].<ref name="Tese"/> Fruits are green, erect or pendulous; they take about eight months to ripe and hold hundreds of thousand yellowish or brownish elongated seeds up to 0.35&nbsp;mm long.<ref>Dressler, Robert L. (1993). Phylogeny and classification of the orchid family. Cambridge University Press.</ref> Among all the mentioned, the main characteristic distinguishing ''Bifrenaria'' from its closest relatives is the presence of the calcar.<ref name="FB">Frederico C. Hoehne (1953). ''Bifrenaria'' in Flora Brasílica, Vol 12, 7. Instituto de Botânica de São Paulo.</ref> Other important characters are the four-sided single-leaved pseudobulbs besides the raceme inflorescence with two to ten flowers.<ref name="Campa">Campacci, Marcos A. (2003). Coletânea de Orquídeas Brasileiras II, ''Bifrenaria''. Ed. Brasil Orquídeas. {{ISSN|1678-5606}}</ref>

Little is known about pollination in ''Bifrenaria''. Apparently the only existing records report the presence of some large species' pollinia observed on the back of male ''[[Eufriesea violacea]]'' bees ([[Euglossinae]]),<ref>Dressler, Robert L. (1990). The orchids natural history and classification. London: Harvard University Press.</ref> and of ''[[Bombus brasiliensis]]'' ([[Bombini]]).<ref>Singer, Rodrigo B. & Koehler, S. (2004). Pollinarium morphology and floral rewards in Brazilian Maxillariinae (Orchidaceae). Annals of Botany 93: 39–51.</ref> Although there are no reports of flower pollination being directly observed, a paper published in 2006 studied the micromorphology of the labellum in ''Bifrenaria'' species, looking for substances useful to [[insect]]s as food.<ref name="Pol">Davies, K.L. & Stpiczynska, M. (2006). Labellar Micromorphology of Bifrenariinae Dressler (Orchidaceae). Annals of Botany Company. Oxford University Press. [https://web.archive.org/web/20081122050252/http://aob.oxfordjournals.org/cgi/reprint/mcl204v1 published on the Internet]</ref> The absence of such substances on the densely pubescent surface of most ''Bifrenaria'' labelli seems to indicate possible pollination by large bees as the major mean. Another indicator of this possibility is the strong smell emanated by species like ''B. tetragona'' which are similar to those of plants in other families which are also pollinated by these bees. The smaller pubescent species may be pollinated by smaller bees, while the smooth ones, which have strong colored flowers, as ''B. aureofulva'', might be pollinated by [[hummingbird]]s.<ref name="Pol"/>

==Taxonomy and phylogeny==
{{Multiple image|direction=vertical|align=left|image1=Bifrenaria charlesworthii 2.jpg|image2=Bifrenaria racemosa 004.jpg|width=200|caption1=''[[Bifrenaria charlesworthii]]'' is a small, pubescent species very similar to ''B. racemosa''.|caption2=Although ''B. racemosa'' can sometimes be separated from ''B charlesworthii'', the large numbers of intermediate forms make some taxonomists think that they might be better treated as a single species.}}
The first ''Bifrenaria'' species to be described was in 1824 by English Botanist [[William Jackson Hooker]], under the name ''[[Bifrenaria harrisoniae|Dendrobium harrisoniae]]''.<ref>Hooker, William Jackson (1824). ''Dendrobium harrisoniae'' in Exotic Flora. 2: t. 120. Edinburgh.</ref> Three years later, he also described the first small-flowered species, ''B. racemosa'', but placed it in ''[[Maxillaria]]''.<ref>Hooker, William Jackson (1827). ''Maxillaria racemosa'' in Botanical Magazine vol. 54: t. 2789. Curtis Ed., London.</ref> With these two publications began a long series of species descriptions and confusing genera creation which generated much doubt for the next two centuries. The [[Royal Botanic Gardens, Kew]] registers the submission of 69 species or subspecific taxa under ''Bifrenaria'' since the description of the first species.<ref name="Kew"/> Among these, twenty are generally accepted but only seventeen are truly well established, with no doubts about their limits and classification. Thirteen other species are still accepted but now placed in other genera, and four or five, due to deficiencies in their descriptions, might never be definitely identified.<ref name="Tese"/>

In 1832, [[John Lindley]] proposed the genus ''Bifrenaria'' and described its [[type species]], ''[[Bifrenaria atropurpurea]]'',<ref>Lindley, John (1832). ''Bifrenaria'' in The Genera and Species of Orchidaceous Plants: 152.</ref> previously named by [[Lodd.|Conrad Loddiges]] as ''Maxillaria atropurpurea''.<ref>Loddiges, Conrad L. (1832). ''Maxillaria atropurpurea'' em Botanical Cabinet vol.19: t.1877. London.</ref> The name ''Bifrenaria'' comes from ''bi'', two, and ''freno'', brake, a reference to the shape of the two pairs of pollinia hold by separated caudicles presented by its flowers.<ref name="FB"/>

In 1837, [[Constantine Samuel Rafinesque]], considering the noticeable vegetative difference between the few ''Bifrenaria'' known at the time, proposed the genus ''Adipe'', based on ''B. racemosa'' morphology, described by Hooker few years before, to which he added the description of a supposed new species, ''Adipe fulva'' (today treated as a synonym of ''B. racemosa'').<ref>Rafinesque, Constantine Samuel (1837). ''Adipe'' in Flora Telluriana vol. 2: 101.</ref> The next year Lindley received a specimen from Amazonia, which was morphologically even more distant from the known species, but nonetheless described it as ''[[Bifrenaria longicornis]]'''. Five years later, apparently not aware of Rafinesque's previous genus ''Adipe'', Lindley changed his mind and suggested that this species should be classified under a new genus, ''Stenocoryne''.<ref>Lindley, John (1843). ''Stenocoryne'' in Edwards's botanical register 29(Misc.): 53 Ed. James Ridgway, London.</ref> Six species were subsequently attributed to ''Stenocoryne'' by various taxonomists, but the genus Rafinesque proposed remained unused until 1990.<ref name=Wolff>{{in lang|de}} Wolff M.(1990)"''Adipe'' Raf., ein 'vergessener Name.'" ''Die Orchidee'' 41:35–37.</ref>

[[Image:Bifrenaria leucorrhoda 2.jpg|thumb|left|''[[Bifrenaria leucorhoda]]'' is one of the easier to identify small species because of its delicate pale pink flowers and darker purple veins on the labellum.]]

Two species similar to ''Bifrenaria'', but that showed a highly salient claw at the base of the labellum and lateral lobes abruptly divided were then classified under this genus. In 1914, [[Friedrich Richard Rudolf Schlechter|Rudolf Schlechter]] suggested they should be classified under the genus ''[[Lindleyella]]'', with Lindley's ''[[Rudolfiella aurantiaca|Bifrenaria aurantiaca]]'' (which presented the mentioned differences) as the type. However this genus name was already occupied (It is a synonym of ''[[Lindleya]]'', in the [[Rosaceae]]).<ref>Schlechter, Rudolf (1914). ''Lindleyella'' in Orchideen: 414.</ref> Just thirty years later, in 1944, [[Frederico Carlos Hoehne]], working on the first revision of genus ''Bifrenaria'', corrected the suggestion of Schlechter. Hoehne initially proposed the genus ''Schlechterella'' for these species but, coincidentally, this name was also taken, this time by African ''[[Asclepiadaceae]]''.<ref>Hoehne, Frederico Carlos (1944). ''Schlechterella'' in Arquivos de Botânica de Estado São Paulo, n.s., f.m., 2: 13.</ref> Finally a genus with an available name in homage to Schlechter was erected in the very next issue of the journal, ''[[Rudolfiella]]'', by which time the number of species had increased to seven. On this revision, besides ''Rudolfiella'', Hoehne divided ''Bifrenaria'' into two genera, accepting Lindley's ''Stenocoryne'' but calling attention to the existence of Rafinesque's ''Adipe'', which should have nomenclatural priority, while also raising doubts about the identity of several described species.<ref>Hoehne, Frederico Carlos (1944). ''Rudolfiella'' in Arquivos de Botânica de Estado São Paulo, n.s., f.m., 2: 14.</ref> In 1990, [[Manfred Wolff]] formally resurrected the genus ''Adipe'' and transferred to it ten ''Bifrenaria'' species, besides the two already described by Rafinesque; his change was purely nomenclatural and he did not revisit the species.<ref name=Wolff/><ref>Koehler, S., N. H. Williams, W. M. Whitten & M. C. E. Amaral. (2002) "Phylogeny of the Bifrenaria (Orchidaceae) complex based on morphology and sequence data from nuclear ''rDNA'' internal transcribed spacers (ITS) and chloroplast ''trnL-trnF'' region." ''International Journal of Plant Sciences'' 163:1055-1066</ref>

Making the picture even more complex, in 1994, Karheinz Senghas, based on several characteristics shared only by ''B. tetragona'' and ''B. wittigii'', described the genus ''Cydoniorchis'' to accommodate them.<ref>Senghas, Karlheinz (1994). ''Cydoniorchis'' em Journal für den Orchideenfreund 1: 11.</ref> In 1996, Gustavo Romero and Germán Carnevali transferred to ''Bifrenaria'' a species originally described by Schlechter as ''Maxillaria petiolaris'' and now classified as ''[[Hylaeorchis|Hylaeorchis petiolaris]]''.<ref>Romero, Gustavo A. & Carnevali, German (1996). ''Bifrenaria petiolaris'' em Richard Spruce: Botanist and Explorer 180.</ref> On the same year, Vitorino Castro Neto published a revision of ''Bifrenaria'', with five sections, which is the classification generally used today.<ref>Castro Neto, Vitorino P. (1996). Contribution to the study of the genus ''Bifrenaria''. Proceedings of the 15th World Orchid Conference. Turriers, Naturalia Publications, Rio de Janeiro, pp. 376-383.</ref>

''Bifrenaria'' has traditionally been classified in subtribe [[Bifrenariinae]] of tribe [[Maxillarieae]] ([[Epidendroideae]]), however, the relationships among the several genera within this tribe are not well defined and changes are expected in the upcoming years. The genus closest to ''Bifrenaria'' is ''[[Rudolfiella]]''. Other related genera are ''[[Teuscheria]]'', ''[[Guanchezia]]'', ''[[Hylaeorchis]]'' and ''[[Horvatia]]'', in addition to the more distant ''[[Scuticaria (plant)|Scuticaria]]'' and ''[[Xylobium]]''. The unification of subtribes [[Lycastinae]], [[Maxillariinae]] and [[Bifrenariinae]] has recently been suggested. However, there is no consensus on the path to be followed.<ref>Whitten, W. Mark, Williams,  Norris H. &  Chase, Mark W. (2000). Subtribal and generic relationships of Maxillarieae (Orchidaceae) with emphasis on Stanhopeinae: combined molecular evidence. American Journal of Botany. 2000;87:1842-1856. [https://web.archive.org/web/20010405015448/http://www.amjbot.org/cgi/content/abstract/87/12/1842 Published on the Internet]</ref> Contrary to what was previously thought, the relationship among ''Bifrenaria'' and all these genera from [[Central America]] seems to indicate a primitive origin of ''Bifrenaria'' in [[Central America]] and its posterior dissemination towards the Southeast of Brazil, where it found fertile grounds to its more recent evolution.<ref name="Tese"/>

In 2000, the first relatively complete molecular analysis on ''Bifrenaria'' species were made.<ref name="Tese"/> Sixteen species from it and six of close genera were studied searching for confirmation of their phylogenetic relations, besides the delimitation of each species and each of ''Bifrenaria'''s groups. The results did not allow for the acceptance of ''Adipe'' as a separate genus and, although they confirmed the monophyly of ''Cydoniorchis'' (''B. tetragona'' and ''B. wittigii''), they dissuade its recognition because six other genera would then be required to accommodate the remaining species. The study also expounded on convenience of splitting two species that are similar to each other and variable among themselves, but with many hard intermediate forms hard to delineate as ''[[Bifrenaria charlesworthii|B. charlesworthii]]'' and ''B. racemosa''. It also confirmed the position of ''B. steyermarkii'' outside of ''Bifrenaria'', but without suggesting a new name.<!--Later studies by the same author specifically avoid the species, usually due to "lack of herbarium material".-->

=== Species ===
[[Image:Bifrenaria vitellina.jpg|thumb|'''''Bifrenaria vitellina'''''<br>This small species is similar to ''B. stefanae'', but its flowers are more open and the colors more vivid.]]

''Bifrenaria'' is formed by about twenty species<ref name="Kew"/> divided in two main groups of plants, large and small, with some visible morphological subdivisions highly confirmed by [[phylogeny]].

'''Large species:''' is the group originally classified as ''Bifrenaria''. They present four sided [[pseudobulb]]s, with relatively short and erect inflorescence bearing up to ten fleshy large flowers but generally less. Usually the flowers are grouped and are fragrant or exhale strong scent. The labellum has three or four lobes and an elongated low callus. They are epiphytes, or often lithophytes. All originated in the southeast of Brazil. This group can be split in three subgroups:<ref name="Tese"/>

*The first subgroup is formed by plants that show a pollinarium with entire stipe and a salient callus just on its anterior region. These species are similar and preferably epiphytes.The species are two:
{| class="wikitable"
|-
! Image !! Scientific Name !! Description !! Distribution !! Elevation (m)
|-
|[[File:Bifrenaria calcarata.jpg|120px]] ||''[[Bifrenaria calcarata|B.  calcarata]]'' {{small|Barb.Rodr. (1882)}}||Has the intermediate lobe of the labellum approximately triangular and the lateral ones square || Brazil (Bahia, Espirito Santo, Rio de Janeiro and São Paulo) ||{{convert|300 - 900|m|ft}} 
|-
|[[File:Bifrenaria mellicolor Orchi 22.jpg|120px]] ||''[[Bifrenaria mellicolor|B. mellicolor]]'' {{small|Barb.Rodr. (1882)}}|| has more rounded lobes. || Brazil (Bahia, Espirito Santo and Rio de Janeiro) ||{{convert|500 - 1000|m|ft}} 
|-
|}
*The second subgroup also is formed by plants that show a pollinarium with entire stipe but the callus is entirely salient and fleshy. It is formed by the two species Senghas moved to genus ''Cydoniorchis'',  
{| class="wikitable"
|-
! Image !! Scientific Name !! Description !! Distribution !! Elevation (m)
|-
|[[File:Bifrenaria tetragona 4.jpg|120px]] ||''[[Bifrenaria tetragona|B. tetragona]]'' {{small|(Lindl.) Schltr. 1908}}||Presents a totally smooth labellum with rounded apex  || Brazil (Espiritu Santo to Rio Grande do Sul and Minas Gerais)||{{convert|300 - 1200|m|ft}} 
|-
|[[File:Bifrenaria wittigii.jpg|120px]] ||''[[Bifrenaria wittigii|B. wittigii]]'' {{small|(Rchb.f.) Hoehne 1953}}|| Has a partially pubescent labellum of acute apex.  || Brazil (Espirito Santo and Rio de Janeiro )  ||{{convert|1000 - 2000|m|ft}} 
|-
|}
*The third subgroup is formed by the six species with a bifurcated stipe. The species of this group are often or exclusively lithophytes.: 
{| class="wikitable"
|-
! Image !! Scientific Name !! Description !! Distribution !! Elevation (m)
|-
|[[File:Bifrenaria atropurpurea.jpg|120px]] ||''[[Bifrenaria atropurpurea|B. atropurpurea]]'' {{small|(Lodd.)Lindley 1832 }}||only species with a cuneated viscidium || Brazil (Minas Gerais, Rio de Janeiro) ||{{convert|200 - 2000|m|ft}} 
|-
|[[File:Bifrenaria tyrianthina Orchi 01.jpg|120px]] ||''[[Bifrenaria tyrianthina|B. tyrianthina]]'' {{small| (Loudon) Rchb. f. 1858 }}||only species to have rounded viscidium || Brazil (Bahia, Espirito Santo and Minas Gerais)||{{convert|1000-2000|m|ft}} 
|-
|[[File:Bifrenaria inodora 41.jpg|120px]] ||''[[Bifrenaria inodora|B. inodora]]'' {{small| Lindl. 1843 }}||greenish flowers and two lobed callus|| Brazil (Espirito Santo, Rio Grande do Sul, Parana, Santa Catarina, São Paulo) ||{{convert|50-1000|m|ft}} 
|-
|[[File:Bifrenaria harrisoniae 5588sf.jpg|120px]] ||''[[Bifrenaria harrisoniae|B. harrisoniae]]'' {{small|(Hooker)Rchb.f 1855}}||highly variable species of several colors, that always has three lobed callus on the labellum ||Brazil (Espirito Santo, Minas Gerais, Parana, Rio Grande do Sul, Santa Catarina, Rio de Janeiro) ||{{convert|200 - 700|m|ft}} 
|-
| ||''[[Bifrenaria diamantinensis|B. diamantinensis]]'' {{small|Capacci & Rosim 2020 }}||densely hairy column, a longer lip and a longer column foot and spur than ''B. harrisoniae''.  ||Brazil (Bahia) ||{{convert|920|m|ft}} 
|-
|[[File:Bifrenaria verboonenii.jpg|120px]] ||''[[Bifrenaria verboonenii|B. verboonenii]]'' {{small|G.A.Romero & V.P.Castro 2000}}|| || Brazil (Minas Gerais) ||{{convert|1000-1400|m|ft}} 
|-
|}



'''Small species:''' is formed by the plants that once belonged to ''Stenocoryne'', or more accurately,  ''Adipe'', which normally are epiphytes. They present smaller and not as noticeably four sided pseudobulbs, and long and delicate inflorescence bearing a higher medium number of flowers than the large species, although also never surpassing ten. The flowers are smaller and not fleshy, with an entire labellum, or sometimes slightly lobed on the apex. These species take less luminosity and more humidity than those and are not particularly fragrant. According to their morphology they can be split in four distinct subgroups:<ref name="Tese"/>

*The first subgroup is formed by the two Amazonian species, with elongated [[rhizome]]: 
{| class="wikitable"
|-
! Image !! Scientific Name !! Description !! Distribution !! Elevation (m)
|-
|[[File:Bifrenaria venezuelana.jpg|120px]] ||''[[Bifrenaria venezuelana|B. venezuelana]]'' {{small|C.Schweinf. (1965)}}||short inflorescence and highly reduced calcar || Venezuela (Rio Negro, Bolivar) ||{{convert|1000-1400|m|ft}} 
|-
|[[File:Bifrenaria longicornis (cropped).jpg|120px]] ||''[[Bifrenaria longicornis|B. longicornis]]'' {{small|Lindl. (1838)}}||long inflorescence and noticeable calcar. || Trinidad & Tobago, French Guiana, Surinam, Guyana, Venezuela, Colombia, Peru and Brazil||{{convert|50-600|m|ft}} 
|-
|}
*Within the second subgroup sepals and petals lanceolate, flowers orange to dark yellow, there is only one species:
{| class="wikitable"
|-
! Image !! Scientific Name !! Description !! Distribution !! Elevation (m)
|-
|[[File:Bifrenaria aureofulva Orchi 02.jpg|120px]] ||''[[Bifrenaria aureofulva|B. aureofulva]]'' {{small|Lindl. (1843)}}||bright orange flowers with acute sepals, petals and labellum, which do not open well. ||Brazil (Bahia, Minas Gerais, Parana, Rio de Janeiro and São Paulo) ||{{convert|200 - 1500|m|ft}} 
|-
|}
*The third subgroup is formed by the two species which present petals que apresentam petals parallel to the column; These two species are hard to separate due to the high number of intermediate varieties: 
{| class="wikitable"
|-
! Image !! Scientific Name !! Description !! Distribution !! Elevation (m)
|-
|[[File:Bifrenaria charlesworthii Orchi 002.jpg|120px]] ||''[[Bifrenaria charlesworthii|B. charlesworthii]]'' {{small|Barb.Rodr. (1882)}}|| More open and hairy flowers ||Brazil ( Bahia, Espirito Santo and Rio De Janeiro) ||{{convert|300 - 1000|m|ft}} 
|-
|[[File:Bifrenaria racemosa 004.jpg|120px]] ||''[[Bifrenaria racemosa|B. racemosa]]'' {{small|(Hook.) Lindl. (1843)}}|| Lateral sepals parallel to each other, labellum scantly pubescent ||Brazil (Rio de Janeiro, São Paulo, Espirito Santo and Minas Gerais ) ||{{convert|300–1000|m|ft}} 
|-
|}
*The last subgroup is formed by species that present petals oblique to the column. Two have petals and sepals marked with other colors:
{| class="wikitable"
|-
! Image !! Scientific Name !! Description !! Distribution !! Elevation (m)
|-
|[[File:Bifrenaria clavigera.jpg|120px]] ||''[[Bifrenaria clavigera|B. clavigera]]'' {{small|Rchb.f. (1865)}}||Has a calcar formed by the fusion of the lateral sepals bases  ||Brazil ( Rio de Janeiro and Espirito Santo ) ||{{convert| 800 - 1000 |m|ft}} 
|-
|[[File:Bifrenaria silvana (cropped).jpg|120px]] ||''[[Bifrenaria silvana|B. silvana]]'' {{small|V.P. Castro (1991)}}||the calcar is a result of their superposition  ||Brazil (Bahia) ||{{convert|500 - 1000|m|ft}} 
|-
|[[File:Bifrenaria leucorrhoda 2.jpg|120px]] ||''[[Bifrenaria leucorhoda|B. leucorhoda]]'' {{small|Rchb.f. (1859)}}|| has white flowers with labellum veined of pink color ||Brazil (Espirito Santo, Rio de Janeiro, and São Paulo) ||{{convert|500 - 1500 |m|ft}} 
|-
|[[File:Bifrenaria stefanae 1.jpg|120px]] ||''[[Bifrenaria  stefanae|B. stefanae ]]'' {{small|V.P. Castro (1991)}}||the smaller and often paler yellow flowers  ||Brazil (Minas Gerais, Parana, Rio de Janeiro and São Paulo) ||{{convert| 900 - 1350|m|ft}} 
|-
|[[File:Bifrenaria vitellina.jpg|120px]] ||''[[Bifrenaria vitellina|B. vitellina]]'' {{small|(Lindl.) Lindl. (1843)}}||larger and of brighter color yellow flowers  ||Brazil (Espirito Santo, Minas Gerais, Rio de Janeiro and São Paulo ) ||{{convert|600 - 1200|m|ft}} 
|-
|}

'''Other species:''' the remaining species are plants about which classification consensus has not been achieved: ''Bifrenaria maguirei'', also classified under the genus ''[[Guanchezia]]'', and ''Bifrenaria grandis'', under ''[[Lacaena]]''. ''[[Bifrenaria steyermarkii]]'' is a species highly different from all other ''Bifrenaria'' because its inflorescence is very long ant its flowers highly narrow, therefore it does not fit in any group, nevertheless the only other option of classification that has been published so far is under ''[[Xylobium]]'' what possibly is not a choice either.

==Distribution and habitat==
[[Image:Bifrenaria inodora 44.jpg|thumb|left|'''''Bifrenaria inodora'''''<br>Despite described with the name of ''B. inodora'', this large species is one of the most fragrant ''Bifrenaria''. It has two main varieties, the one on the photo was also described as ''B. fuerstenbergiana'' and has this varietal name, the other one is greener and has a yellow labellum.]]

''Bifrenaria'' exist from the north of South America, one species reaching [[Trinidad]], until [[Rio Grande do Sul]], the farther south State in [[Brazil]], however they are split in two isolated areas:<ref name="Kew">R. Govaerts, M.A. Campacci (Brazil, 2005), D. Holland Baptista (Brazil, 2005), P.Cribb (K, 2003), Alex George (K, 2003), K.Kreuz (2004, Europe), J.Wood (K, 2003, Europe): World Checklist of Orchidaceae. The Board of Trustees of the Royal Botanic Gardens, Kew. [http://www.kew.org/wcsp Published on the Internet.] (Access March 2009).</ref> Amazon Forest and [[Atlantic Forest]] of Brazil. The later, where seventeen species are present, may be considered their recente center of distribution. The montane area of [[Rio de Janeiro State]] and [[Espírito Santo]] is particularly rich with fifteen species registered. [[Serra dos Órgãos]] mountains area, in Rio, is reported as habitat of fourteen  ''Bifrenaria'' species,<ref name="DM">Miller, David, Richard Warren, Izabel Moura Miller & Helmut Seehawer (2006). Serra dos Órgãos sua história e suas orquídeas. Rio de Janeiro.</ref> however, some of these species are considered synonyms today,<ref>Koehler, S. & do Amaral, M.D.E. (2004). A taxonomic study of the South American genus ''Bifrenaria'' Lindl. (Orchidaceae). Brittonia 56: 314-345.</ref><!--probably the same as ref. #6 "tese", need to check whether the portuguese version can be dropped--> being eleven a more realistic number of species existing in the said area.

The species with large flowers are more common on [[Region Southeast of Brazil]], however, they inhabit from the sunnier areas of the seashore to rocky mountain areas of [[Minas Gerais]] e [[Bahia]] States, from almost sea level up to 2,000 meters of [[altitude]], some species reaching [[Rio Grande do Sul]] state.<ref name="IOBBA">Castro Neto, Vitorino P.  (2006). ''Bifrenaria atropurpurea''  in Icones Orchidacearum Brasilienses. {{ISBN|85-901494-4-7}}</ref> No species of large flowers exist in Amazon Forest. Some species grow directly attached to the famous [[Sugarloaf Mountain]] in Rio de Janeiro which can be observed by the commuters in the cable car. The recent centers of irradiation of this group are the seashore close to [[Serra do Mar]] chain of mountains, and the high chains of mountains of Minas Gerais.<ref name="FB"/> The most common species in this group, spread from Rio Grande do Sul to Bahia, is ''[[Bifrenaria harrisoniae|B. harrisoniae]]''.<ref name="IOBBH">Castro Neto, Vitorino P.  (2006). ''Bifrenaria harrisoniae'' in Icones Orchidacearum Brasilienses. {{ISBN|85-901494-4-7}}</ref>

The smaller species of ''Bifrenaria'', which some taxonomists classify under the genus ''Adipe'', are more common on less sunny areas and can be found between 300 and about 1,600 meters of altitude.<ref name="DM"/> Six species are native in Serra do Mar Chain of mountains and its arms, place considered the center of distribution of the small species. Only three small species inhabit Amazon, ''[[Bifrenaria longicornis|B. longicornis]]'', which is more common at low artitudes;<ref name="Tese">Koehler, Samantha (2001). Estudo taxonômico e análise cladástica do complexo ''Bifrenaria'' Lindl. (Maxillarieae, Orchidaceae). Universidade Estadual de Campinas. Instituto de Biologia. [http://libdigi.unicamp.br/document/?code=vtls000241393 Published on the Internet] {{Webarchive|url=https://web.archive.org/web/20090619035018/http://libdigi.unicamp.br/document/?code=vtls000241393 |date=2009-06-19 }}</ref> ''[[Bifrenaria venezuelana]]'', up to 1,450 meter of altitude, and ''[[Bifrenaria steyermarkii|B. steyermarkii]]'' from even higher altitudes, in [[Roraima]] State, in Brasil, and nearby areas in [[Venezuela]] and [[Suriname]].<ref>Freitas Luz, Francisco J. (2001). Orquídeas na Amazônia. Instituto Brasileiro de Cultura, Ed. On Line. {{ISBN|85-208-0208-7}}</ref>

The most common species is ''[[Bifrenaria aureofulva|B. aureofulva]]'',<ref name="EdwardsBA">Lindley, John (1843). ''Bifrenaria aureofulva'' in Edwards's botanical register 29: t.52. Ed. James Ridgway, London.</ref> however, because the geographic characteristic of its territory, without obstacles, ''[[Bifrenaria longicornis|B. longicornis]]'' is the species spread throughout the largest area, reaching [[Colombia]], [[Venezuela]], [[Peru]], [[Suriname]], [[Guyana]]s, Trinidad and all Amazonic area in Brazil.<ref name="EdwardsBL">Lindley, John (1838). ''Bifrenaria longicornis'' in Edwards's botanical register 24: t.93. Ed. James Ridgway, London.</ref> Two species seem to be [[Endemism|endemic]] in highly restricted areas: ''[[Bifrenaria silvana|B. silvana]]''. discovered in 1987 at [[Serra da Ouricana]] mountains, nearby [[Itororó]], in [[Bahia]] which belongs to ''Adipe'' group;<ref>Castro Neto, Vitorino P. (1991). ''Bifrenaria silvana'' in Boletim CAOB 3(4): 41.</ref> and ''[[Bifrenaria verboonenii|B. verboonenii]]'', discovered in September 1995 on [[Serra do Cipó]] mountains, close to [[Diamantina, Minas Gerais|Diamantina]], [[Minas Gerais]], of the large ''Bifrenara'' group.<ref>Romero, Gustavo A. & Castro Neto, Vitorino P. (2000). ''Bifrenaria verboonenii'' in Harvard Papers of Botany 5: 187 Cambridge.</ref>

[[Image:Bifrenaria harrisoniae 0.jpg|thumb|'''''Bifrenaria harrisoniae'''''<br>This is the most variable species of all ''Bifrenaria'': there are numberless colors varieties. It can be distinguished from ''B. tyrianthyna'' only through its three keeled callus and shorter calcar.]]

''Bifrenaria'' species inhabit three different environments. The large species generally live in well illuminated areas, occasionally [[Epiphytically|epiphyte]] on trees of sparse foliage, more often as [[lithophyte]]s, in [[campos rupestres]], montane rocky areas that exist mostly in Rio and Minas Gerais States of Brazil, or over rocks in jungle's clearances. ''B. tyrianthina'' is exclusively lithophyte,<ref>Toscano de Brito, Antonio & Cribb, Phillip (2005). ''Bifrenaria tyrianthina'' in Orquídeas da Chapada Diamantina. Ed. Nova Fronteira. {{ISBN|85-209-1782-8}}</ref> ''B. tetragona'' and ''B. wittigii'' hardly ever do. ''B. atropurpurea'' is the only species found living terrestrially, but in rare occasions. The large species always show .<ref name="Tese"/>

The small species from Southeast Brazil live in [[cloud montane forest]]s, where the appear in much darker places than the large species. Within this sort of forests the [[temperature]] presents noticeable difference between day and night and also through the seasons. These also are plants of [[caespitous growth]], almost all epiphytes, despite there is at least one record of ''Bifrenaria aureofulva'' living lithophylically in [[Chapada Diamantina]], Bahia.<ref>Toscano de Brito, Antonio & Cribb, Phillip (2005). ''Bifrenaria aureofulva'' in Orquídeas da Chapada Diamantina. Ed. Nova Fronteira. {{ISBN|85-209-1782-8}}</ref>

The species from Amazon inhabit tropical [[lowland]] forests and [[equatorial forest]]s. ''Bifrenaria longicornis'' is mostly found in flood areas along the [[igapó]]s and [[Igarapés (waterway)|igarapés]] (seasonal flood streams and small rivers of Amazon), and occasionally in open fields where the [[humidity]] is high and [[temperature]] constant through the year, normally in well illuminated places, although not under direct [[sunlight]].<ref>Miranda, Francisco (2006). Orquídeas da Amazônia Brasileira. Ed. Expressão e Cultura, 1996. {{ISBN|85-208-0208-7}}</ref> ''B. venezuelana'' inhabits forests in higher elevations, closer to the [[Andes]].<ref>Castro Neto, Vitorino P.  (2002). ''Bifrenaria venezuelana''  in Icones Orchidacearum Brasilienses. {{ISBN|85-901494-4-7}}</ref> Amazon species are epiphyte and the only ''Bifrenaria'' species with elongated [[rhizome]] and [[ascendant growth]].

==Cultivation==
[[Image:Bifrenaria tetragona 2.jpg|thumb|''Bifrenaria tetragona'' has a strong scent of rotten meat and is not suitable for house decoration.]]
''Bifrenaria'' are comparatively easy to grow orchids. They should be preferably potted on well drained vegetable fiber because their roots and pseudobulbs rot easily when kept humid for long periods. One of three different environments is needed depending on the species' origin to successfully grow these plants. The larger species need more light than the others. The smaller species from Southeast Brazil may be cultivated at the same medium temperature but under less than 10-20% [[luminosity]]. ''Bifrenaria'' from the Amazon Forest require higher and more constant [[temperature]] and [[humidity]] than other species. All species need most [[water]] and [[fertilizer]] during their active growth season.<ref Name="FB"/>
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== References ==
*{{citizendium}}
<references/>

== External links ==
*{{Commons-inline|2=''Bifrenaria''}}
*{{Wikispecies-inline|Bifrenaria|''Bifrenaria''}}

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[[Category:Bifrenaria| ]]
[[Category:Maxillariinae genera]]
[[Category:Epiphytic orchids]]