The family 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). It also includes Vanilla–the genus of the vanilla plant, the type genus Orchis, and many commonly cultivated plants such as Phalaenopsis and Cattleya. Moreover, since the introduction of tropical species into cultivation in the 19th century, horticulturists have produced more than 100,000 hybrids and cultivars.
The Epidendroideae subfamily is the most widespread subfamily. It represents more than eighty percent of orchid species, and includes over 10,000 types of orchids. Although members of the Epidendroideae subfamily are present in temperate regions, they are most prevalent in the tropics of the Eastern and Western hemispheres. There orchids typically have single anthers with sub-erect structures.
Water thoroughly. When you do water, do it like you mean it. Different growers have different rules, but many professional growers turn on their sprinklers for 8 or more minutes. Successful home-growers sometimes dunk their plants, pots and all, into a bucket or sink of water. Some varieties, such as vandas, can be left floating in water for a surprisingly long time. The idea is to make sure the velamen is completely saturated. You want tiny droplets hanging on the roots after watering. This means the plant is completely hydrated.
The Gongora orchid genus is a really neat type of orchids, related to Stanhopea. They have nice, strong fragrances, often of cinnamon, allspice, or nutmeg. The flower stems hang over the pot's edge and the flowers point downwards. They can adapt to a wide variety of lighting conditions and a relatively large temperature range, but like a lot of water.
Orchids of all types have also often been sought by collectors of both species and hybrids. Many hundreds of societies and clubs worldwide have been established. These can be small, local clubs, or larger, national organisations such as the American Orchid Society. Both serve to encourage cultivation and collection of orchids, but some go further by concentrating on conservation or research.
The quality of water used, whether for spraying or watering, is of great importance. Since tap water has often been chemically treated, generally with chlorine, it should be used with caution. The best water for orchids is undoubtedly rainwater. Rainwater, as it passes through the air, dissolves and absorbs many substances such as dust, pollen and other organic matter. This enriched rainwater contributes to the nourishment of the plant.
The Coelogyne orchid genus gets a lot less attention than it deserves. The plants have beautiful, fragrant flowers, can tolerate drought and neglect, and rapidly develop into massive, impressive specimens. The best-known species come from the foothills of the Himalayas, where the elevation produces cool temperatures. The largest-flowered species in the genus, Coelogyne cristata, is one of these cool-growing types.
The Sobralia orchid genus grows ubiquitously in much of South and Central America; I've heard them called "ditchweed"! They have beautiful, short-lived flowers whose appearance is somewhat similar to a large Cattleya orchid. Flowers can be more than 6 inches (15cm) across in some species. The plants can get quite large, however, so you need to have enough space for them!