Phalaenopsis, the Moth Orchid, is one of the most commonly available and easiest to grow orchid genera. It is an especially good choice for beginners to orchid growing. They have large, showy flowers that come in a wide variety of colors. Most species have several flowers per stem, but some have more, and others have as few as one or two. There are a great many hybrid varieties on the market. 

Oncidium, perhaps more accurately the oncidium alliance, are a group of plants from South America that span a wide range of habitats. Inside the oncidium alliance there are a number of genera that hybridize freely to create what we call intergeneric oncidium hybrids. These can come in all sorts of shapes and sizes but are generally characterized by large quantities of small to medium flowers borne on a branched stem that generally forms a Christmas-tree shape. The most commonly identified Oncidium are the yellow “dancing lady” type.
Anguloa, the Tulip Orchid, is well described by its common name! They have substantial, tulip-shaped flowers in shades of white, green, yellow, and red. They like a lot of humidity, intermediate-to-bright light, and cool-to-intermediate temperatures. They really like humidity and hate drying out during the growing season, but most need a dry rest after flowering.
The orchid plant is also unique in its morphology (form or structure). We can begin with the leaves and work our way down to the roots. The leaves of many orchids in cultivation are unique in that they are specifically designed for water conservation (as is true for almost every orchid structure). They have a heavy waxy leaf coating and specialized stomata (openings through which the leaf “breathes”) that help to prevent water loss during transpiration (the act of the plant “breathing”). Many orchids utilize CAM photosynthesis as well, which in essence means that the plants collect materials during the day and then process them at night.
Disa is a genus of beautiful plants with rather triangular flowers, often red. They require VERY different care than other types of orchids, so it's easy to kill them if you don't know what you're doing. In particular, they like it wet and should never dry out. The best-known Disa is Disa uniflora, which in South Africa is known as the Pride of Table Mountain.
The variety of orchid plant types is amazing. Some bloom for weeks at a time, while others keep their flowers an amazing four months or more. Always check the tag that comes with the plant to determine the optimum temperature for your orchid. Choose one that fits in with your normal indoor environment, rather than trying to change your environment to fit the orchid.
Some orchids have water-storing organs, and some do not. If you have a type of orchid that has the ability to store water, such as cattleyas or oncidiums, you should allow the orchid to completely dry out before watering. If you have a type of orchid that does not have water-storing organs, such as phalaenopsis or paphiopedilums, you should water the orchid before it is entirely dry.

So you want to grow an orchid? There are tens of thousands of orchid varieties to choose from, in almost every color of the rainbow. Some exotic versions are rarely seen outside specialty shows, while others are readily available to the novice grower. Unlike the common stereotype, many types of orchids will thrive as houseplants, and don’t need to be kept in a greenhouse. The orchid you’ll choose to grow will depend on the environment in your home, as well as the way the plant looks.
To give you a better feel for how orchid subfamilies, tribes, and genera are interconnected, we created a compendium of popular American orchids. It plots over 100 “local” genera of orchids so you can see just how impressive and expansive this family is. You may be surprised that some of these vibrant, exotic looking orchids exist in your own backyard!  Want to learn more about flowers and plants? Check out our other compendiums featuring types of roses and types of desert plants.
Because these orchids are top-heavy with lots of blooms on each stem, this type of orchid often requires staking. There are over 1,000 species in this category, and they usually come in colors such as white, lavender, or yellow. One of its biggest advantages is the fact that it can grow almost anywhere, regardless of the zone you live in, and some of them keep their leaves all year long. They can also come in more than one color per bloom, which makes them especially attractive.

The family encompasses about 6–11% of all seed plants.[4] 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 indoor types of orchids, including cattleya and phalaenopsis orchids, produce flowers that last months at a time. When these houseplants start blooming, the flower show continues for a long window—from four to 16 weeks. Cymbidium orchids produce up to 35 flowers per blossom spike, and each spike lasts up to eight weeks. Phalaenopsis orchid flowers can linger from 80 to 120 days.  
Cymbidium carry tall stems with many flowers that have a more typical orchid shape. They are easily identified by their grassy leaves, and they readily form large clumps. Most common are the cool-flowering types, which need to experience a cooler winter (nights in the 40s for some time in the fall) in order to initiate flowering. Once the flowers open, they can last for up to two months or more, especially in a cool environment. These are very showy and rewarding plants, and a plant in a six-inch pot can carry three stems with 15 or more flowers each, depending on the type.