Bulbophyllum | |
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Bulbophyllum echinolabium | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Asparagales |
Family: | Orchidaceae |
Subfamily: | Epidendroideae |
Subtribe: | Dendrobiinae |
Genus: | Bulbophyllum Thouars, 1822 [1] |
Type species | |
Bulbophyllum nutans | |
Species | |
Diversity | |
2167 species | |
Synonyms [2] | |
List of synonyms
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Bulbophyllum is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is the largest genus in the orchid family and one of the largest genera of flowering plants with more than 2,000 species, exceeded in number 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. [3] 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 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.
Plants in the genus Bulbophyllum are epiphytic or lithophytic sympodial herbs 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 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 petals 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. [1] [4] [5] [6]
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, [7] though the genus is pantropical and widespread, occurring in Australia, Southeast Asia (with over 200 species in Borneo), India, Madagascar (with 135 species, some endemic), Africa and in tropical central and South America. [6]
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 flowers arranged spirally or in two vertical ranks. The sepals and the petals 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 present or absent. The fruits are beakless capsules. [6]
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. [1] [8]
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. [6]
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. [9] [6]
In 2014, Alec Pridgeon and others proposed merging the genus Drymoda with Bulbophyllum in the Genera Orchidacearum and the change is accepted by Plants of the World Online and the World Checklist of Selected Plant Families. [10] [11] [12] The former species of Drymoda included D. digitata (now B. digitatum ), [13] D. gymnopus (now B. gymnopus ), [14] D. latisepala (now B. capillipes ), [15] D. picta (the type species of Drymoda, now B. drymoda ), [16] and D. siamensis (now B. ayuthayense ). [17]
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. [18]
In 2019 Bulbophyllum were separated into four clades Neotropics, Africa, Madagascar, and the Asia-Pacific. [19] [20]
Image | Section | Type species |
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Bifarium | Bulbophyllum bifarium | |
Carnosisepala | Bulbophyllum carnosisepalum | |
Chaseela | Bulbophyllum pseudohydra | |
Comata | Bulbophyllum comatum | |
Denticulata | Bulbophyllum denticulatum | |
Genyorchis | Bulbophyllum apetalum | |
Gilgiana | Bulbophyllum gilgianum | |
Megaclinium | Bulbophyllum falcatum | |
Ptiloglossum | Bulbophyllum barbigerum | |
Oreonastes | Bulbophyllum oreonastes | |
Many Bulbophyllum species have the typical odor of rotting carcasses, and the flies they attract assist in their reproduction through pollination. [6] 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. [21] [22] [23] [24] [25]
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. [26] [27] [28]
Bulbophyllum (abbreviated Bulb. in the horticultural trade) [29] 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. [30]
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. [30]
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 in bloom has been likened to smelling like a herd of dead elephants and both this species and Bulbophyllum fletcherianum 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. [30]
Some species are known for their extreme vegetative and floral forms:
Some Bulbophyllum species are threatened with extinction, and are recognised as such by the World Conservation Union (IUCN):
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 Earth except glaciers. The world's richest diversity of orchid genera and species is found in the tropics.
A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.
Pleurothallis is a genus of orchids commonly called bonnet orchids. The genus name is derived from the Greek word pleurothallos, meaning "riblike branches". This refers to the rib-like stems of many species. The genus is often abbreviated as "Pths" in horticultural trade.
Brassavola is a genus of 21 orchids. They were named in 1813 by the Scottish botanist Robert Brown. The name comes from the Italian nobleman and physician Antonio Musa Brassavola. This genus is abbreviated B. in trade journals.
Cymbidium, commonly known as boat orchids, is a genus of evergreen flowering plants in the orchid family Orchidaceae. Orchids in this genus are epiphytic, lithophytic, terrestrial or rarely leafless saprophytic herbs usually with pseudobulbs. There are usually between three and twelve leaves arranged in two ranks on each pseudobulb or shoot and lasting for several years. From one to a large number of flowers are arranged on an unbranched flowering stem arising from the base of the pseudobulb. The sepals and petals are all free from and similar to each other. The labellum is significantly different from the other petals and the sepals and has three lobes. There are about fifty-five species and sixteen further natural hybrids occurring in the wild from tropical and subtropical Asia to Australia. Cymbidiums are well known in horticulture and many cultivars have been developed. The genome of Cymbidium mannii has been sequenced to study epiphytism and crassulacean acid metabolism.
Zoophily, or zoogamy, is a form of pollination whereby pollen is transferred by animals, usually by invertebrates but in some cases vertebrates, particularly birds and bats, but also by other animals. Zoophilous species frequently have evolved mechanisms to make themselves more appealing to the particular type of pollinator, e.g. brightly colored or scented flowers, nectar, and appealing shapes and patterns. These plant-animal relationships are often mutually beneficial because of the food source provided in exchange for pollination.
Carrion flowers, also known as corpse flowers or stinking flowers, are mimetic flowers that emit an odor that smells like rotting flesh. Apart from the scent, carrion flowers often display additional characteristics that contribute to the mimesis of a decaying corpse. These include their specific coloration, the presence of setae and orifice-like flower architecture. Carrion flowers attract mostly scavenging flies and beetles as pollinators. Some species may trap the insects temporarily to ensure the gathering and transfer of pollen.
Zingerone, also called vanillylacetone, is a major flavor component of ginger, providing the sweet flavor of cooked ginger. Zingerone is a crystalline solid that is sparingly soluble in water and soluble in ether.
A semiochemical, from the Greek σημεῖον (semeion), meaning "signal", is a chemical substance or mixture released by an organism that affects the behaviors of other individuals. Semiochemical communication can be divided into two broad classes: communication between individuals of the same species (intraspecific) or communication between different species (interspecific).
Interspecies communication is communication between different species of animals, plants, or microorganisms. Although researchers have explored the topic for many years, only recently has interspecies communication been recognized as an established field of inquiry.
Bactrocera dorsalis, previously known as Dacus dorsalis and commonly referred to as the oriental fruit fly, is a species of tephritid fruit fly that is endemic to Southeast Asia. It is one of the major pest species in the genus Bactrocera with a broad host range of cultivated and wild fruits. Male B. dorsalis respond strongly to methyl eugenol, which is used to monitor and estimate populations, as well as to annihilate males as a form of pest control. They are also important pollinators and visitors of wild orchids, Bulbophyllum cheiri and Bulbophyllum vinaceum in Southeast Asia, which lure the flies using methyl eugenol.
Raspberry ketone is a naturally occurring phenolic compound that is the primary aroma compound of red raspberries.
Bactrocera cucurbitae, the melon fly, is a fruit fly of the family Tephritidae. It is a serious agricultural pest, particularly in Hawaii.
Bulbophyllum frostii, commonly known as Frost's bulbophyllum or Dutchman's shoes is a species of orchid, In the wild it grows as an epiphyte, inhabiting evergreen seasonal lowland rainforests in Vietnam and more rarely in Thailand, including the Malay peninsula. It was more recently reported growing in the Yunnan province of China during a series of botanical surveys between 2017 and 2020. This plant is usually found at elevations of around 1500m above sea level.
Bulbophyllum baileyi, commonly known as the fruit fly orchid, is a species of epiphytic or lithophytic orchid that is native to Queensland and New Guinea. It has coarse, creeping rhizomes, curved, yellowish pseudobulbs with a single thick, fleshy leaf, and a single cream-coloured flower with yellow, red or purple spots. It grows on trees and rocks in open forest, often in exposed places.
Methyl eugenol (allylveratrol) is a natural chemical compound classified as a phenylpropene, a type of phenylpropanoid. It is the methyl ether of eugenol and is important to insect behavior and pollination. It is found in various essential oils.
Bulbophyllum nocturnum is a species of epiphytic orchid that grows in New Britain. It was described in 2011, and is the first species of orchid known to consistently flower during the night, and close its flowers during the day.
An attractant is any chemical that attracts an organism, e.g. i) synthetic lures; ii) aggregation and sex pheromones ; and iii) synomone
The pollination of orchids represents a complex aspect of the biology of this plant family, characterized by intricate flower structures and diverse ecological interactions with pollinator. Notably, the topic has garnered significant scientific interest over time, including the attention of Charles Darwin, who is recognized for his contributions to the theory of evolution by natural selection. In 1862, Darwin published his observations on the essential role of insects in orchid pollination in his work The Fertilization of Orchids. He noted that the various strategies employed by orchids to attract their pollinators are complex.
Bulbophyllum sect. Sestochilos is a section of the genus Bulbophyllum.