The Orchidaceae, commonly referred to as the orchid family, is a morphologically diverse and widespread family of monocots in the order Asparagales. Along with the Asteraceae, it is one of the two largest families of flowering plants, with between 21,950 and 26,049 currently accepted species, found in 880 genera.
Selecting which of the two families is larger remains elusive because of the difficulties associated with putting hard species numbers on such enormous groups. Regardless, the number of orchid species equals more than twice the number of bird species, and about four times the number of mammal species.
It also encompasses about 6–11% of all seed plants. The largest genera are Bulbophyllum (2,000 species), Epidendrum (1,500 species), Dendrobium (1,400 species) and Pleurothallis (1,000 species).
The family also includes Vanilla (the genus of the vanilla plant), Orchis (type genus), and many commonly cultivated plants such as Phalaenopsis and Cattleya. Moreover, since the introduction of tropical species in the 19th century, horticulturists have produced more than 100,000 hybrids and cultivars.
The world’s richest concentration of orchid varieties is found in the tropics, mostly Asia, South America and Central America, but they are also found above the Arctic Circle, in southern Patagonia, and even two species of Nematoceras on Macquarie Island, close to Antarctica.
Let’s view a gallery of some exquisite orchids from around the world.
Bulbophyllum is the largest genus in the orchid family Orchidaceae. With more than 2,000 species, it is also one of the largest genera of flowering plants, exceeded only by Astragalus. This genus is abbreviated in the trade journals as Bulb.
The fabulous and bizarre species that comprise this large genus 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 have an ever blooming habit and will flower continuously throughout the year. They tend to prefer moderate light levels, but do not like deep shade.
They are considered moderate to difficult in cultivation, 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 of these species 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 and 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 and prefer moist conditions all the time.
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 dislike 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 are warmth loving and cannot tolerate cold temperatures or freezing.
The flowers produce various odors resembling sap, urine, blood, dung, carrion, and some species fragrant fruity aromas. Most of these species are fly pollinated, and attract hordes of flies, but not all of the species in this very large genus.
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.
Zygopetalum is a genus of the orchid family (Orchidaceae) (subfamily Epidendroideae, tribe Maxillarieae, subtribe Zygopetalinae), consisting of fourteen species.
This orchid’s generic name, derived from the Greek word “zygon”, means “yoked petal.” It refers to the yoke-like growth at the base of the lip caused by the fusion of petals and the sepals.
They occur in humid forests at low- to mid-elevation regions of South America, with most species in Brazil. Most are epiphytes, but some are terrestrials with glossy, strap-like, plicate leaves, which are apical, oblong or elliptic-lanceolate, acute or acuminate. These orchids have a robust growth form. Their ovoid-conical pseudobulbs are deciduous.
They produce an erect, 60 centimeter-long, few-flowered to several-flowered, racemose inflorescence that grows laterally and is longer than the leaves. Their prominent bracts equal the length of the ovary. They are known for their fragrant, waxy, and long-lived flowers with multiple blooms in shades of green, purple, burgundy, and raspberry with several patterns.They are known for their ease of culture and are much in demand as excellent cut flowers.
Miltonia, abbreviated Milt. in the horticultural trade, is an orchid genus formed by nine epiphyte species and eight natural hybrids inhabitants of the Brazilian Atlantic Forest, one species reaching the northeast of Argentina and east of Paraguay. This genus was established by John Lindley in 1837, when he described its type species, Miltonia spectabilis.
Many species were attributed to Miltonia in the past, however, today, the species from Central America and from cooler areas on northwest of South America have been moved to other genera. Miltonia species have large and long lasting flowers, often in multifloral inflorescences. This fact, allied to being species that are easy to grow and to identify, make them a favorite of orchid collectors all over the world. Species of this genus are extensively used to produce artificial hybrids.
Despite the fact that Miltonia is now a well established genus, most of its species were originally classified under other genera as Cyrtochilum, Oncidium, Odontoglossum, and Brassia. All were discovered between 1834 and 1850 with the exception of M. kayasimae, discovered only in 1976.
These epiphytic orchids occur from Central to Southern Brazil down to Argentina. These orchids have two leaves, arising from a pseudobulbs, covered with a foliaceous sheath. The inflorescence consists of waxy, nonspurred flowers. The lip is large and flat and lacks a callus at its base. They possess a footless column with two hard pollinia. The flowers have a delicate, exotic scent, some compare to that of roses.
They are named after Lord Fitzwilliam Milton, an English orchid enthusiast.
The species in this genus are sometimes confused with the pansy orchids, but it is the other miltoniopsis orchids that have flowers that closely resemble the pansy. Almost everyone except for the most serious orchid hobbyists use these names interchangeably, which may cause confusion.
Miltonia looks more like oncidiums than the real pansy orchids. The most “pansy-like” a miltonia can get is the species Miltonia spectabilis. Taxonomists are debating whether to put miltonia into the oncidium genus because of the many connections between the two.
Miltoniopsis is the pansy orchid with huge showy flowers. They grow in cooler climates and are more challenging to grow than miltonias.
Oncidium, abbreviated as Onc. in the horticultural trade, is a genus that contains about 330 species of orchids from the subtribe Oncidiinae of the orchid family (Orchidaceae). This is a complex, difficult genus, with many species being reclassified. Calls are made for splitting this genus into multiple genera.
This genus was first described by Olof Swartz in 1800 with the orchid Oncidium altissimum, which has become the type species. Its name is derived from the Greek word “onkos”, meaning “swelling”. This refers to the callus at the lower lip.
Most species in the Oncidium genus are epiphytes, although some are lithophytes or terrestrials. They are widespread from northern Mexico, the Caribbean, and some parts of South Florida to South America.
Oncidium species are characterised by the following properties :
- presence of column wings
- presence of a complicated callus on the lip (this can be used to separate the taxa).
- pseudobulbs with one to three leaves.
- several basal bracts at the base of the pseudobulbs.
The flowers of the Oncidium genus come in shades of yellow, red, white and pink. The petals are often ruffled on the edges, as is the lip. The lip is enormous, partially blocking the small petals and sepals.
They are known as ‘spray orchids’ among some florists. They are very varied and are easily hybridised with Odontoglossum.
Stanhopea (J. Frost ex Hook. 1829) is a genus of the orchid family (Orchidaceae) from Central and South America. The abbreviation used in horticultural trade is Stan. The genus is named for the 4th Earl of Stanhope (Philip Henry Stanhope) (1781-1855), president of the Medico-Botanical Society of London (1829-1837).
These epiphytic, but occasionally terrestrial orchids can be found in damp forests from Mexico to NW Argentina. Their ovate pseudobulbs carry from the top one long, plicate, elliptic leaf.
It is noted for its complex and usually fragrant flowers that are generally spectacular and short-lived. Their pendant inflorescences are noted for flowering out of the bottom of the containers in which they grow, lending themselves to culture in baskets that have enough open space for the infloresence push through. They are sometimes called upside-down orchids.
Primitive Stanhopeas Most Stanhopea flowers flash prominent, elegant horns on the epichile. The exception are the species; S. annulata, S. avicula, S. cirrhata, S. ecornuta and S. pulla. A second group have short or truncated horns, they include the species; S. candida, S. grandiflora, S. reichenbachiana, S. tricornis and the natural hybrid S. x herrenhusana. The structure of the labellum of this group is in general, not as complex as other members of the genus.
With most Stanhopea flowers lasting three days or less, the blooms must attract pollinators very quickly. These chemical attractants are generated in the hypochile, attracting the male euglossine bees to the flower. When the bee touches down on the flower, a great effort is made to collect chemical scent – he eventually slides on the waxy surface of the hypochile, gliding down on the slippery lip to exit the flower.
The long column is touched in the process, resulting in the bee taking up pollinia at the very tip of the column. When the bee slides down another flower, the pollinia are deposited on the sticky surface of the stigma.
The majority of species are robust plants that grow readily in cultivation. For relatives of Stanhopea see Stanhopeinae and the closely related sister subtribe Coeliopsidinae..
Brassia is a genus of orchids classified in the Oncidiinae subtribe. The genus was named after William Brass, a British botanist and illustrator, who collected plants in Africa under the supervision of Sir Joseph Banks. Its abbreviation in the horticultural trade is Brs.
Brassia species and its popular hybrids are common in cultivation, and are notable for the characteristic long and spreading tepals (in some clones longer than 50 cm), which lend them the common name “spider orchid”.
This epiphytic genus occurs in South Florida, the West-Indies and tropical America, in wet forests from sea level to altitudes under 1500 m, with the Peruvian Andes as its center. Occurrence is mostly restricted to a certain area, but Brassia caudata can be found over the whole geographic area.
They have large elliptic-oblong pseudobulbs with one or two leaves at the apex, lateral, unbranched many-flowered inflorescences with small floral bracts. The lip is not attached to the column. The pollinarium shows a narrow stipe. There are two distichous, foliaceous sheaths around the base, from which the inflorescence emerges.
Brassia has a very specific method for pollination : it uses entomophily : pollination by insects and in this case specifically by female spider-hunter wasps of the genera Pepsis and Campsomeris. Mistaken by the mimicry of Brassia, the wasp stings the lip, while trying to grasp its prey without any success. By these movements the wasp comes into contact with the pollinarium, that then sticks to its head. By flying to another Brassia flower, this flower gets pollinated.
Phalaenopsis abbreviated Phal in the horticultural trade, is an orchid genus of approximately 60 species. Phalaenopsis is one of the most popular orchids in the trade, through the development of many artificial hybrids.
The generic name means “Phalaen[a]-like” and is probably a reference to the genus Phalaena, the name given by Carolus Linnaeus to a group of large moths; the flowers of some species supposedly resemble moths in flight. For this reason, the species are sometimes called Moth orchids.
They are native throughout southeast Asia from the Himalayan mountains to the islands of Polillo, Palawan and Zamboanga del Norte in the island of Mindanao in the Philippines and northern Australia. Orchid Island of Taiwan is named after this genus. Little recent information about their habitat and their ecology in nature is available since little field research has been done in the last decades.
Most are epiphytic shade plants; a few are lithophytes. In the wild, some species grow below the canopies of moist and humid lowland forests, protected against direct sunlight; others grow in seasonally dry or cool environments. The species have adapted individually to these three habitats.
Possessing neither pseudobulbs nor rhizome, Phalaenopsis shows a monopodial growth habit: a single growing stem produces one or two alternate, thick, fleshy, elliptical leaves a year from the top while the older, basal leaves drop off at the same rate.
If very healthy, a Phalaenopsis plant can have up to ten or more leaves. The inflorescence, either a raceme or panicle, appears from the stem between the leaves. They bloom in their full glory for several weeks. If kept in the home, the flowers may last two to three months. Some Phalaenopsis species in Malaysia are known to use subtle weather cues to coordinate mass flowering.
Laelia, abbreviated L. in the horticultural trade, is a small genus of 25 species from the orchid family (Orchidaceae). This is one of the most important and popular orchid genera, because of the beautiful flowers, their genetic properties and because they are fairly easy in culture. It is probably named after Laelia, one of the Vestal Virgins. Another possibility is the name borne by female members of the Roman patrician family of Laelius.
Laelia species are found in the subtropical or temperate climate of Central America, but mostly in Mexico. Laelia speciosa is a high-elevation plant, preferring sunny, dry and cool conditions. The others grow in the rainforest with a warm, humid summer and a dry cool winter. The species L. albida, L. anceps and L. autumnalis prefer higher and cooler altitudes.
Laelia is one of the orchid genera known to use crassulacean acid metabolism photosynthesis, which reduces evapotranspiration during daylight because carbon dioxide is collected at night.
Most are epiphytes, but a few are lithophytes, such as Laelia anceps. They are closely related to Cattleya, but have twice as many pollinia. Stems are usually short, however the stem of Laelia anceps can be more than 1 m long. The ovate pseudobulbs are clearly separate. These are about 6 – 30 cm long. One or two waxy, leathery leaves develop from each pseudobulb. This leaf can be up to 20 cm long.
The inflorescence is a raceme, which can be 30 cm long, with up to eight flowers, growing from the top of the pseudobulb. These flowers can be pink to purple, with a beautifully colored purple lip becoming white close to the column . They bloom in spring or autumn. Albino varieties are rare and therefore prized. Due to high demand for such a rare mutations, many horticultural labs use modern tissue culture or mericloning techniques to increase their availability.
Members of this genus tend to be fairly easy in culture, and some plants are surprisingly drought-tolerant. Culture is highly dependent upon the natural habitat of the species in question, although many do well as mounted (plaqued) specimens so that the roots receive plenty of air circulation and a sharp wet-and-dry cycle.
The “Brazilian Laelias, after being classified for several years under Sophronitis, have now been placed in the genus Cattleya, to avoid confusion.
Several species of the now-defunct genus Schomburgkia have been added to the genus Laelia.
Laelia species readily form hybrids within the genus, and with other genera, including Cattleya, Brassavola, and Rhyncholaelia.
Cattleya is a genus of 113 species of orchids from Costa Rica to tropical South America. The genus was named in 1824 by John Lindley after Sir William Cattley who received and successfully cultivated specimens of Cattleya labiata that were used as packing material in a shipment of other orchids made by William Swainson.
They are widely known for their large, showy flowers, and were used nus is abbreviated C in trade journals. extensively in hybridization for the cut-flower trade until the 1980’s when pot plants became more popular. This genus and the numerous hybrids come close, through their beauty, to the idealized picture we have of the orchids.
The flowers of the hybrids can vary in size from 5 cm to 15 cm or more. They occur in all colors except true blue and black.The typical flower has three rather narrow sepals and three usually broader petals: two petals are similar to each other, and the third is the quite different conspicuous lip, featuring various markings and specks and an often frilly margin. At the base, the margins are folded into a tube. Each flower stalk originates from a pseudobulb. The number of flowers varies; it can be just one or two, or sometimes up to ten.
Cymbidium or boat orchids, is a genus of 52 evergreen species in the orchid family Orchidaceae. It was first described by Olof Swartz in 1799. The name is derived from the Greek word kumbos, meaning ‘hole, cavity’. It refers to the form of the base of the lip. The genus is abbreviated Cym in horticultural trade.
This genus is distributed in tropical and subtropical Asia (such as northern India, China, Japan, Malaysia, the Philippines, and Borneo) and northern Australia. The larger flowered species from which the large flowered hybrids are derived grow at high altitudes.