Bulbophyllum Sect. Epicrianthes
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''Bulbophyllum'' is a genus of mostly
epiphytic An epiphyte is an organism that grows on the surface of a 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 epiphytes grow are called phoroph ...
and
lithophytic 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 ...
orchids in the family Orchidaceae. It is the largest genus in the orchid family and one of the largest genera of flowering plants with more than 2,000 species, exceeded in number only by '' Astragalus''. These orchids are found in diverse habitats throughout most of the warmer parts of the world including Africa, southern Asia, Latin America, the West Indies, and various islands in the Indian and Pacific Oceans. Orchids in this genus have thread-like or fibrous roots that creep over the surface of trees or rocks or hang from branches. The stem is divided into a
rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...
and a pseudobulb, a feature that distinguished this genus from '' Dendrobium''. There is usually only a single leaf at the top of the pseudobulb and from one to many flowers are arranged along an unbranched flowering stem that arises from the base of the pseudobulb. Several attempts have been made to separate ''Bulbophyllum'' into smaller genera, but most have not been accepted by the World Checklist of Selected Plant Families.


Description

Plants in the genus ''Bulbophyllum'' are epiphytic or lithophytic sympodial
herbs In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...
with thread-like or fibrous roots that creep over the surface on which they grow. The stem consists of a rhizome and a pseudobulb, the latter with one or two usually fleshy or leathery leaves. The flowers are arranged on an unbranched
raceme A raceme ( or ) or racemoid is an unbranched, 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 produced as the s ...
that emerges from the pseudobulb, usually from its base. The dorsal sepal is free from the lateral sepals which themselves may be free or fused to each other. The
petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...
s are also free from each other and smaller than the lateral sepals. The labellum is often fleshy, curved and hinged to the base of the
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. ...
.


Taxonomy and naming

The genus ''Bulbophyllum'' was first formally described in 1822 by Louis-Marie Aubert du Petit-Thouars in his book ''Histoire particulière des plantes orchidées recueillies sur les trois Iles Australes d’Afrique, de France, de Bourbon et de Madagascar'' in which he described eighteen species of ''Bulbophyllum. There are now more than 2,800 records (accepted names and synonyms) for this genus. This large number and the great variety of its forms make the genus a considerable challenge for taxonomists: 120 sections and subgenera have been listed. The genus name (''Bulbophyllum'') is derived from the Greek ''bolbos'' meaning 'bulb' and ''phyllon'', 'a leaf', referring to the pseudobulbs on top of which the leaf grows. In 2014,
Alec Pridgeon Alec or Aleck is a Scottish form of the given name Alex. It may be a diminutive of the name Alexander or a given name in its own right. Notable people with the name include: People * Alec Aalto (1942–2018), Finnish diplomat *Alec Acton (1938– ...
and others proposed merging the genus ''Drymoda'' with ''Bulbophyllum'' in the ''Genera Orchidacearum'' and the change is accepted by
Plants of the World Online Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...
and the World Checklist of Selected Plant Families. The former species of ''Drymoda'' included ''D. digitata'' (now '' B. digitatum''),, ''D. gymnopus'' (now '' B. gymnopus''), ''D. latisepala'' (now '' B. capillipes''), ''D. picta'' (the type species of ''Drymoda'', now '' B. drymoda''), and '' D. siamensis'' (now '' B. ayuthayense'').


Sections


Distribution and habitat

The center of diversity of this genus is in the montane forests of Papua New Guinea (more than 600 species) which seems to be the evolutionary homeland, though the genus is pantropical and widespread, occurring in
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
, Southeast Asia (with over 200 species in Borneo), India, Madagascar (with 135 species, some endemic), Africa and in tropical central and South America. The erect to pendent inflorescence arises laterally from the base of the pseudobulb. The flower form has a basic structural blueprint that serves to identify this genus. But this form can be very diverse : compound or single, with few to many flowers, with the
resupinate Resupination is derived from the Latin word ''resupinus'', meaning "bent back with the face upward" or "on the back". "Resupination" is the noun form of the adjective "resupine" which means "being upside-down, supine or facing upward". The word " ...
flowers arranged spirally or in two vertical ranks. The sepals and the
petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...
s can also be very varied : straight or turned down, without footstalk or with a long claw at the base. They are often hairy or callous. There are two to four hard and waxy pollinia with
stipes Crucifixion is a method of capital punishment in which the victim is tied or nailed to a large wooden cross or beam and left to hang until eventual death from exhaustion and asphyxiation. It was used as a punishment by the Persians, Carthagin ...
present or absent. The fruits are beakless capsules.


Evolution and biogeography

Molecular phylogenetic studies place the origin of the orchid genus Bulbophyllum into the early Miocene. Biogeographic analyses and ancestral area reconstructions identified the Asia-Pacific region as the ancestral area of Bulbophyllum and suggest an early-to-late Miocene scenario of ‘out-of-Asia-Pacific’ origin and progressive (east-to-west) dispersal-mediated diversification, resulting in three additional radiations in Madagascar, Africa and the Neotropics, respectively.


Ecology


Pollination

Many ''Bulbophyllum'' species have the typical odor of rotting carcasses, and the flies they attract assist in their reproduction through pollination. Nevertheless, some species with mild and pleasant floral fragrance attract Dacini fruit flies (particularly ''Bactrocera'' and ''Zeugodacus'' species) via methyl eugenol, raspberry ketone or zingerone that also act as floral reward during pollination. To facilitate pollinarium removal and pollinia deposition, this group of orchids, particularly those that attract Dacini fruit flies, possesses a highly modified dynamic lip mechanism - either hinged or see-saw or spring lip (kept either in a close- or open-position depending on resupinate or non-resupinate flower, respectively). When an attracted fly has aligned itself to the opened lip, further probing, feeding and movement towards the lip base result in the lip to snap close, thereby, forcibly tipping the fly in to the column cavity to initiate pollinarium removal or pollinia deposition.


Use in horticulture

''Bulbophyllum'' (abbreviated ''Bulb.'' in the horticultural trade)Alphabetical List of Standard Abbreviations for Natural and Hybrid Generic Names
Royal Horticultural Society, 2017.
includes species that have been the focus of orchid collectors for over a century. The plants require high humidity combined with good air movement and most of them are ever-blooming - flowering continuously throughout the year. They grow best at moderate light levels, but do not thrive in deep shade. They are considered moderate-to-difficult to cultivate, and require a controlled growing environment to achieve some degree of success. They are not typically suitable as houseplants, and most will not thrive in a Wardian case unless they receive adequate air movement. The plants' growth habit produces widely spaced pseudobulbs along cord-like rhizome sections, and most of these plants are best accommodated on plaques. Some species in this genus can get very large, but most are small to medium-sized epiphytes from warm, moist, humid tropical forests. They can grow continuously year round with no apparent dormancy period if they are kept warm, are moderate feeders in cultivation, and must be kept moist all the time. They can tolerate dryness for short periods, but they have fine root systems which require moist conditions all the time.Illustrated Encyclopedia of Orchids Some of the smaller species do well in pots with small-diameter bark substrate. The plants produce very fine roots generally, and the roots are easily damaged. The plants react poorly to disturbance of their roots. They are easy to maintain once a good environment is established with high humidity and a fresh, buoyant, lightly circulating atmosphere being critical. Most of these species cannot tolerate cold temperatures or freezing. The flowers produce various odors resembling sap, urine, blood, dung, carrion, and, in some species, fragrant fruity aromas. Most are fly-pollinated, and attract hordes of flies. ''
Bulbophyllum beccarii ''Bulbophyllum beccarii'' is by far the largest species in the genus ''Bulbophyllum'' and one of the largest in the orchid family. The thick rhizome, reportedly up to 20 cm in diameter (but the thickest reliably reported has been five cm.) ...
'' in bloom has been likened to smelling like a herd of dead elephants and both this species and ''
Bulbophyllum fletcherianum ''Bulbophyllum fletcherianum'', the tongue orchid, Fletcher's bulbophyllum or Spies' bulbophyllum, is a rare orchid native to southern New Guinea. It prefers sunny rock outcrops or mossy tree branches, but besides being lithophytic or epiphytic, ...
'' are variously described as making it difficult to walk into a greenhouse in which they are being cultivated if the plants are in bloom because of their overpowering floral odors.


Species

Some species are known for their extreme vegetative and floral forms: *''
Bulbophyllum beccarii ''Bulbophyllum beccarii'' is by far the largest species in the genus ''Bulbophyllum'' and one of the largest in the orchid family. The thick rhizome, reportedly up to 20 cm in diameter (but the thickest reliably reported has been five cm.) ...
'' *''
Bulbophyllum barbigerum ''Bulbophyllum barbigerum'' (bearded bulbophyllum) is a species of orchid found in parts of West and Central Africa Central Africa is a subregion of the African continent comprising various countries according to different definitions. ...
'' *''
Bulbophyllum falcatum ''Bulbophyllum falcatum'' is a species of plant in the family Orchidaceae endemic to tropical Africa from Sierra Leone up to the Congo Basin, Congo and western Uganda. It is a member of the section Megaclinium. It has rachis In biology, a ra ...
'' *''
Bulbophyllum santosii ''Bulbophyllum santosii'' is a species of orchid in the genus ''Bulbophyllum''. It is endemic to the Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, link ...
'' *''
Bulbophyllum macphersonii ''Bulbophyllum macphersonii'', commonly known as eyelash orchids, is a species of epiphytic or lithophytic orchid that is endemic to Queensland. It has tiny, crowded, slightly flattened, dark green pseudobulbs, a single thick, fleshy leaf and a ...
'' *''
Bulbophyllum medusae ''Bulbophyllum medusae'', commonly known as the Medusa orchid, is a species of epiphytic orchid with a creeping rhizome and a single leaf about long emerging from the top of each pseudobulb. The flowers are creamy yellow and arranged in clusters ...
''


Conservation status

Some ''Bulbophyllum'' species are threatened with extinction, and are recognised as such by the World Conservation Union (IUCN): *''
Bulbophyllum bifarium ''Bulbophyllum bifarium'', or two-sided bulbophyllum, is an epiphytic (occasionally lithophytic) plant species in the family Orchidaceae, flowering in November and endemic to Cameroon. Its natural habitats are subtropical or tropical moist lowla ...
'' (vulnerable) *'' Bulbophyllum filiforme'' (critically endangered) *''
Bulbophyllum gravidum ''Bulbophyllum gravidum'' is a species of epiphytic plant in the family Orchidaceae that is found in Equatorial Guinea and Cameroon ( Bioko and Mount Cameroon, respectively). Its natural habitats are in montane, subtropical or tropical dry fore ...
'' (vulnerable) *''
Bulbophyllum jaapii ''Bulbophyllum jaapii'' is a species of plant in the family Orchidaceae. It is endemic to Cameroon. Its natural habitat is subtropical or tropical moist montane forests. It was described botanically in 2001. The distribution and range of ''B. ...
'' (vulnerable) *''
Bulbophyllum kupense ''Bulbophyllum teretifolium'' is a species of plant in the family Orchidaceae. It is an epiphyte with cylindrical leaves and up to about forty small, white and purplish flowers and is endemic to Cameroon. Its natural habitat is subtropical or tro ...
'' (critically endangered) *''
Bulbophyllum modicum ''Bulbophyllum modicum'' is a possibly extinct, epiphytic plant species in the family Orchidaceae. It is endemic to Cameroon, and its natural habitat (montane subtropical or tropical dry forests of Mount Cameroon between 900 and 1,200 meters in ...
'' (endangered) *''
Bulbophyllum nigericum ''Bulbophyllum nigericum'' is an epiphytic or epilithic plant species in the family Orchidaceae. It is native to Cameroon ( Enyandong, Mt Kupe and the Bakossi Mountains), and Nigeria, where it is found growing habitually in submontane and monta ...
'' (vulnerable) *''
Bulbophyllum pandanetorum ''Bulbophyllum pandanetorum'' is a rare species of epiphytic plant in the family Orchidaceae. It is found in Cameroon and Gabon, where its natural habitat is subtropical or tropical moist lowland forests at elevations roughly between 200 and 950 ...
'' (endangered) *''
Bulbophyllum rubrolabellum ''Bulbophyllum rubrolabellum'' is a species of plant in the family Orchidaceae that is endemic to Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the ...
'' (endangered) *''
Bulbophyllum tokioi ''Bulbophyllum tokioi'' is a species of plant in the family Orchidaceae. It is Endemism, endemic to Taiwan (has been found in the north and central regions in or near Taipei, Hsinchu and Taichung). It was described in 1935 by Noriaki Fukuyama. I ...
'' (endangered)


Gallery

Image:Bulbophyllum baileyi var alba.jpg, ''B. baileyi'' var.'' alba'' Image:Bulbophyllum_falcatum.jpg, ''B. falcatum'' Image:Bulbophyllum-lepidum.jpg, ''B. flabellum-veneris'' Image:Bulbophyllum-putidum.jpg, ''B. putidum'' Image:Bulbophyllum-pectenveneris.jpg, ''B. pectenveneris'' Image:B.translucidum.jpg , ''B.translucidum''


References


Bibliography

* J.J. Vermeulen : Orchid Monographs Vol. 7 (1993), ''A taxonomic revision of Bulbophyllum, sections Adelopetalum, Lepanthanthe, Macrouris, Pelma, Peltopus, and Uncifera (Orchidaceae''). iv + 324 pp., 25 text-figs. + 116 full-page line drawings, 6 pp. colour plates. * Siegerist E.S.: - ''Bulbophyllums and their allies'' Timber Press, 2001, 77 colour photos, 296 pp - devoted solely to Bulbophyllums, it is an introductory guide for amateur and advanced orchid growers.


External links


''Bulbophyllum'' page

The ''Bulbophyllum'' - Checklist
{{Taxonbar, from=Q134091 Dendrobieae genera Epiphytic orchids