Dendrobium orchids are found throughout the western Pacific and east Asia from as far north as Japan to as far south as Tasmania and southern New Zealand, east to Tahiti and west to western India (Lavarack et al. 2000). The genus (as currently delineated) includes more than a thousand species found in widely varying habitats (Lavarack et al. 2000; Adams et al. 2006). Like most other epiphytes, Dendrobium orchids are restricted to areas of moderate to high rainfall (e.g., in tropical lowlands, annual rainfall of more than 150 cm and a dry season of less than 6 months; at higher elevations in the tropics, or in cooler temperate regions, drier conditions can be tolerated). Dendrobium are found from just above the treeline on the highest mountains to the branches of trees overhanging the ocean. They are absent from some of the drier forests and woodlands, deserts and semi-deserts, and alpine and other cold environments. They are mainly inhabitants of primary forest, especially the rainforests of Southeast Asia and New Guinea. Swamp forests (such as those dominated by Melaleuca species) and mangrove forests may also support large numbers of individuals and species. Relatively few Dendrobium species are found in monsoonal forests and woodlands, but populations of species that do occur in these habitats can be dense. The small number of species found in the subalpine shrubbery of tropical mountains are of particular interest in that most of them have brightly colored flowers. Some species are well adapted to disturbed habitats. (Lavarack et al. 2000)
As a consequence of the fact that the genus includes many species that are generally compact, fabulously colorful, and often easy to grow, Dendrobium are among the most horticulturally important orchids. Given the great range of habitats and altitudes at which various species grow, some appropriate species can be found for cultivation in most climates. Although there are many rare and endangered species, Dendrobium are common in both the wild and in gardens in southern Asia; the Malesian Islands (i.e., the islands to the east of Southeast Asia, including New Guinea), the Pacific Islands (the islands south and east of the Solomon Islands, the endemic-rich New Caledonia being the largest of these), and Australia. New Guinea has the greatest diversity of Dendrobium, both in number of species and in diversity per unit area. Lavarack et al. review the historical biogeography of Dendrobium. (Lavarack et al. 2000)
Dendrobium orchids vary in size from tiny creeping plants less than a centimeter high (e.g., D. toressae) to clumped bamboo-like plants several meters tall (e.g., D. discolor). Although most are epiphytes, some grow on rocks or on the ground. All Dendrobium (even the terrestrial species) have coarse, spreading root systems, unlike the tuberous root systems characteristic of terrestrial orchids from temperate regions. (Lavarack et al. 2000)
Dendrobium orchids typically produce large numbers of very small and easily dispersed seeds. These seeds contain almost no food reserves. Seedlings must quickly form mycorrhizal associations with appropriate fungi to supply them with needed nutrition as they develop. (Lavarack et al. 2000)
Perhaps a third of the 30,000 or so orchid species are deceptive, attracting pollinators but then failing to reward them with pollen or nectar. Many of these orchids imitate the scent of rewarding flowers or potential mates. However, one rewardless Dendrobium orchid, Dendrobium sinense, is pollinated by the hornet Vespa bicolor, which it apparently attracts by mimicking the alarm pheromone produced by honeybees, which hornets frequently hunt as food for their larvae (Brodmann et al. 2009).
Wang et al. (2009) developed inter-simple sequence repeat (ISSR) genetic markers for diagnosing species and studying genetic diversity in Dendrobium. Xue et al. (2010) constructed genetic linkage maps for two Dendrobium species using random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) markers. These maps, which cover 92.7% and 82.7% of the D. hercoglossum and D. officinale genomes, respectively, should facilitate mapping of horticultural and medicinal traits (around 40 Dendrobium species have been used in traditional Chinese medicine) and be useful for marker-assisted selection in Dendrobium breeding programs.
Lavarack et al. (2000) review the history of orchid collecting and current conservation threats to orchids in the wild and discuss potential solutions to respond to these challenges.
The pseudobulbs of D. canaliculatum and D. speciosum were used as food by the aboriginal Australians. Other Dendrobium species have been used for a range of culinary, medicinal, putative aphrodisiacs, and other purposes. Lavarack et al. (2000) review basic propagation techniques. (Lavarack et al. 2000)
Dendrobium is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is a very large genus, containing more than 1,800 species that are found in diverse habitats throughout much of south, east and southeast Asia, including China, Japan, India, the Philippines, Indonesia, Australia, New Guinea, Vietnam and many of the islands of the Pacific. Orchids in this genus have roots that creep over the surface of trees or rocks, rarely having their roots in soil. Up to six leaves develop in a tuft at the tip of a shoot and from one to a large number of flowers are arranged along an unbranched flowering stem. Several attempts have been made to separate Dendrobium into smaller genera, but most have not been accepted by the World Checklist of Selected Plant Families.
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Dendrobium species are mostly epiphytic, or lithophytic although a few species are terrestrial. They are sympodial herbs with cylindrical roots usually arising from the base of a pseudobulb. The pseudobulbs, when present, are hard, sometimes cane-like, cylindrical or cone-shaped and more or less covered with the bases of the leaves. There are from one to many leaves arranged in two ranks, the leaves varying in shape from linear to oblong, sometimes cylindrical but never channelled or grooved. They are usually much longer than wide and last for only a single season.[3][4][5]
Between one and a large number of resupinate or non-resupinate flowers are arranged along an unbranched flowering stem and may be short or long-lived. The flowers may be white, green, yellow, or pink to purple, often with contrasting colours in the labellum. The sepals and petals are usually free from and more or less similar to each other but markedly different from the labellum. The labellum is more or less egg-shaped, with the narrower end towards the base and flanks the column. There is often a callus consisting of narrow, parallel ridges, in the centre of the labellum.[3][4][5]
The genus Dendrobium was first formally described in 1799 by Olof Swartz and the description was published in Nova Acta Regiae Societatis Scientiarum Upsaliensis.[1][6] The name Dendrobium is derived from the ancient Greek words dendron meaning "tree" and bios meaning "life", referring to the epiphytic habit of most species.[6][7]
In 1981, Friedrich Brieger reclassified all terete-leaved dendrobiums from Australia and New Guinea into a new genus, Dockrillia and in 2002 David Jones and Mark Clements separated the genus into smaller genera, including Thelychiton, Tropilis, Vappodes and Winika but all of these genera are regarded as synonyms by the World Checklist of Selected Plant Families.[1]
In 2009, the online Flora of China divided the genus into the following sections:[8]
Orchids in the genus Dendrobium have adapted to a wide variety of habitats, from the high altitudes in the Himalayan mountains to lowland tropical forests and even to the dry climate of the Australian desert.
Dendrobium is abbreviated as Den. by the Royal Horticultural Society.[9] Some species are in great demand by orchid lovers. This has resulted in numerous varieties and hybrids, such as the noble dendrobium (Den. nobile) breeds, which have greatly extended the range of colors of the original plant from the Himalayas. The flowers of Cuthbertson's dendrobium (Den. cuthbertsonii) have been reported to last up to ten months each.
Many Dendrobium species are known to vigorously remove toluene and xylene from the air.[10]
Several hybrids in this genus have been registered and named after notable persons and institutions:
The grex Dendrobium Berry gx[12] has received the Royal Horticultural Society's Award of Garden Merit.
Some Dendrobium species are cultivated as medicinal plants.[13] The noble dendrobium (D. nobile) for example is one of the 50 fundamental herbs used in traditional Chinese medicine, where it is known as shí hú (石斛) or shí hú lán (石斛兰).
The 1889 book 'The Useful Native Plants of Australia records that Dendrobium canaliculatum was called "yamberin" by the Indigenous People of Queensland, Australia and that "The bulbous stems, after being deprived of the old leaves are edible (Thozet)."[14]
Many species and cultivars of this genus are well-known floral emblems and have been figured in artwork. Among the former are:
The Cooktown orchid was figured on Australian stamps in 1968 and 1998, and flowers of several Dendrobium greges are depicted on the obverse side of the Singapore Orchid Series currency notes issued between 1967 and 1976:
The golden-bow dendrobium (D. chrysotoxum), colloquially called fried-egg orchid was one of the species grown by the fictional private detective and orchid fancier Nero Wolfe, and plays a role in The Final Deduction.
Dendrobium Chet's Choice (Dendrobium densiflorum × farmeri), a hybrid belonging to the section Densiflorum (syn. Callista)
![Dendrobium 'Mini Brown'[verification needed], a hybrid belonging to the section Spatulata](http://en.wikipedia.org/wiki/File:Dendrobium-Mini-Brown.jpg)
Dendrobium 'Mini Brown', a hybrid belonging to the section Spatulata
Painting of a typical Dendrobium by I. V. Passmoore, probably the hybrid Dendrobium Lucky Seven
Dendrobium Margaret Thatcher, a hybrid belonging to the section Spatulata
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Dendrobium hybrid belonging to the section Phalaenanthe
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Dendrobium hybrid
Dendrobium from Kottayam
Dendrobium is a genus of mostly epiphytic and lithophytic orchids in the family Orchidaceae. It is a very large genus, containing more than 1,800 species that are found in diverse habitats throughout much of south, east and southeast Asia, including China, Japan, India, the Philippines, Indonesia, Australia, New Guinea, Vietnam and many of the islands of the Pacific. Orchids in this genus have roots that creep over the surface of trees or rocks, rarely having their roots in soil. Up to six leaves develop in a tuft at the tip of a shoot and from one to a large number of flowers are arranged along an unbranched flowering stem. Several attempts have been made to separate Dendrobium into smaller genera, but most have not been accepted by the World Checklist of Selected Plant Families.
Labelled diagram of Dendrobium kingianum
