The plants in this genus are often the first ones grown by amateur orchid lovers and afterward probably make up a respectable portion of their collections.
There are 65 cattleya species and a large number of varieties and natural hybrids.
All cattleyas are epiphytic and are found in the New World tropics.
Although some species are native to relatively cold zones, most of them thrive at a range of average temperatures, from 12 to 20°C.
Cattleyas are sympodial plants, which means that their pseudobulbs grow for only one season. As their name suggests, bifoliate cattleyas usually have two rounded or elliptical leaves on their fairly long, cylindrical pseudobulbs. Unifoliate cattleyas have a single, fleshy longer leaf on each short, swollen pseudobulb. Although this distinction is used by growers, it is of little botanical significance.
The species in the unifoliate group produce 2 to 5 large flowers at the apex of each pseudobulb, while those in the bifoliate group produce many more, but much smaller, flowers. The blooms are almost always highly scented and may be white, yellow, mauve, pink, red, orange or even green, and are sometimes marked with stains, lines or spots in a contrasting colour. While some species bloom in summer, most are autumn or spring flowering.
There are more hybrids registered for this group than for any other orchid genus – thousands of them, in fact. Many species and hundreds of hybrids have been successfully crossed with several other related genera, resulting in a profusion of flower shapes and colours. The plants may range in size from ten centimetres or so to over one metre. The names of these many intergeneric crosses (e.g., x Brassolaeliocattleya) may be highly confusing to beginners!
This genus was cultivated in China 5,000 years ago. Cymbidium ensifolium is probably one of the oldest orchid species in cultivation.
Cymbidiums are terrestrial, lithophytic and sometimes epiphytic plants.
In the wild, they are found from India, China and Japan to Australia and the Solomon Islands.
Cymbidiums have ovoid, spherical pseudobulbs, which vary in size depending on the species and that produce long, narrow, strap-like leaves.
The erect or pendant flower stalks emerge from the base of mature pseudobulbs and generally bear 5 to 15 good-sized flowers. The lip is wide and usually spotted or stained. The petals and sepals are similar and usually solid-coloured, but sometimes spotted.
The flower colours are predominantly green, brown, yellow and pink. The blooms are usually scented and are initiated in the fall or winter in most of the cultivated species and hybrids. Thousands of hybrids have been obtained by crossing the different cymbidium species.
Most dendrobiums are epiphytic. Their natural range is from throughout India and Sri Lanka to New Zealand and Australia. They are found both at sea level in the moist tropics and on the slopes of the Himalayas, a much colder habitat.
These plants vary in size from tiny, shrunken pseudobulbs no more than 3 cm tall to gigantic species like the New Guinea Dendrobium violaceoflavens, whose cylindrical pseudobulbs can be 5 to 6 m tall.
The inflorescences bear from one to dozens of blooms, in a wide range of colours, shapes and sizes. Shades of red, pink and white are very common, although yellow, orange, magenta and other colours are also found. Many are scented and others not.
Plants labelled as miltonias by growers belong to two closely related genera: Miltoniopsis and Miltonia.
Together, they represent some twenty species and a few natural hybrids.
Miltonias are epiphytic plants, sometimes lithophytic.
They are found from sea level to high altitudes, on cold slopes in the Andean Cordillera. Their natural range is from Mexico, through the Andes to southern Brazil.
Flower stalks that will bear from one to several blooms rise from the base of the most recent pseudobulbs.
Those species native to the Andes, mostly belonging to the Miltoniopsis genus, have pansy-like flowers that are usually flat, white or pink, often with purple markings.
Brazilian species, in the Miltonia genus, produce more star-shaped flowers, yellow or greenish, with brown, purple or red markings.
They bloom throughout the year, depending on the species. Some are lightly scented.
Oncidiums were among the first orchids grown in England in the early 19th century.
In those days, they were said to flower only once before dying, but this reputation was more a matter of growing methods at the time than these species’ biology. When you think that these plants are native to cool regions at altitudes above 2,000 m, it is understandable that they survived only briefly when grown in hot, humid, furnace-like greenhouses.
Oncidiums are mostly epiphytic, although some are lithophytic or terrestrial. Some species grow at sea level, while others are from mountainous regions. Their natural range extends from southern Florida to Brazil and Argentina.
They come in an extremely broad range of shapes.
Some are upright, others arching, but most have well-defined, often elongated and flattened pseudobulbs.
These structures are usually partially covered in several sheath-like leaves.
One group includes only species without pseudobulbs – their fleshy, triangular-section leaves are equitant, or fan-shaped, like iris leaves. Any new shoot from a plant usually produces one and sometimes two flower stalks, which bear one or two large flowers, or an enormous cluster of small flowers. The blooms are usually yellow with brown markings, and range in size from very tiny to 12 cm in diameter. Some oncidiums also come in shades of green, white, red, magenta and pink.
Paphiopedilums are terrestrial or lithophytic, very rarely epiphytic, plants. They usually grow on thick humus made up of plant litter, mosses, fern rhizomes and all kinds of roots.
They are found in the wild from China and the Himalayas, throughout southeast Asia and Indonesia, to New Guinea.
Paphiopedilums are sympodial plants without pseudobulbs. They are very unlike the epiphytic plants that are normally cultivated.
There are 81 species and 4 natural hybrids in the Paphiopedilum genus.
The long leaves are fairly wide and range in colour, depending on the species, from solid green to green mottled or marbled with white; the undersides are sometimes purple-tinged.
The flowers, often large and very showy, are borne individually or in small clusters at the end of short or longer inflorescences, all parts of which are often very hairy. The blooms are predominantly green, brown, yellow and white.
The flowering period often begins in the fall, winter or spring, although some species bloom in summer.
Thousands of hybrids have been created for this genus. Most of them have been incorrectly registered as Cypripedium, a name often used as a synonym for Paphiopedilum.
The name comes from the Greek and means resembling a moth. For this reason, they are commonly called moth orchids.
Their ample blooms and the fact that many species are easy to grow make these orchids very popular indoor plants.
Most phalaenopsis are epiphytic, while a few are lithophytic.
They are found in the Himalayas, China and southeast Asia all the way to New Guinea and northern Australia.
Phalaenopsis are monopodial plants with a short, constantly growing stem and leaves that overlap at the base. The leaves are broad and fairly fleshy, usually green but sometimes mottled with white, and sometimes with purple-tinged undersides.
Depending on the species, the inflorescences are of different lengths and may be pendant or upright, often ramified. They bear from one to dozens of medium-sized or fairly large blooms, mostly in shades of white, yellow and pink.
Some species are highly scented, while others are unscented.
Flowering usually begins between the fall and spring and a fully mature specimen may produce flowers for several months, if not year round.
There are a huge number of hybrids in this genus. Some of them have large, flat, solid-colour blooms, while others have usually smaller flowers with streaks, spots, lines, etc.
Like cymbidiums, vandas have been cultivated since the days of ancient China.
Today, there are some fifty species of vandas.
All vandas are native to Asia, from China to New Guinea.
Most are epiphytic, although some are lithophytic or even terrestrial.
Epiphytic vandas have fleshy roots that hang down one or two metres. This allows them to take advantage of ambient humidity and frequent rainfall, while enjoying maximum aeration.
Vandas are monopodial plants with very long, often climbing stems. Most species have strap-like leaves, although they are round and pencil-shaped in some species like Vanda teres.
The inflorescences grow from the top part of the stem and bear a variable number of fairly large, usually fleshy flowers. Flower colours vary enormously, but the predominant hues are browns, purples, magentas, yellows and blues.
Depending on the species, these orchids bloom throughout the year.
Based on articles by Céline Arseneault and by Denis Barabé in Quatre-Temps magazine.