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.
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.
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.
Always water early in the day so that your orchids dry out by nighttime. The proper frequency of watering will depend on the climatic conditions where you live. In general, water once a week during the winter and twice a week when the weather turns warm and dry. The size of your orchid container also helps determine how often you need to water, regardless of climate conditions. Typically, a 6-inch pot needs water every 7 days and a 4-inch pot needs water every 5 to 6 days.
Orchids have become very popular houseplants in recent years, with their delicate blooms adding elegance and allure to any room. But for beginners, knowing how to water orchids may seem a bit daunting, since they are unlike other common houseplants. This article is going to focus on how to water phalaenopsis orchids. These are also called moth orchids, and are one of the most popular and widely available varieties of orchid.
There are lots of orchid photos. I spent 16 days in country and managed to visit Sao Paulo state beaches, littoral plain and littoral mountains as well as the Mantiquera Mountains and up to Diamantina in northern Minas Gerais all by car with the well known Brazilian orchid expert, Marcos Campacci. The name may ring a bell as he is the describer of many new Brazilian orchid species such as Cattleya tenuis. He is also the editor of Boletim CAOB and Brasil Orqueideas, 2 major orchid publications in Brazil.
The den-phal type are warm growing year round and do, just by happenstance, bear flowers similar in appearance to the genus Phalaenopsis. They can be distinguished by plant habit (most Dendrobium have pseudobulbs that resemble tall canes) and flower shape. Den-phals have a spur at the back of the lip; some are more pronounced, others less. They are also borne on very strong upright to barely arching stems. Interesting to note, den-phals can rebloom on old canes.
The petals of these orchids are a bit smaller than those of other orchids, and it consists of many spikes so there are a lot of those petals to look at. The Cymbidium orchid has won several international flower awards, and it comes in colors such as yellow and red (the Showoff), lime green (the Chica), and bright pink (the Frae). These and other Cymbidiums are excellent for first-time growers, because they are easy to grow and are low-maintenance. They also do better in cold climates than many other orchids do, and they make beautiful centerpieces.

Cool growing Colombian Orchids - Photos of Orchids in situ near Bogota' Colombia - #1 Epidendrum sp., #2 Epidendrum polystachyum",#2 Epidendrum polystachyum young plant,#3 Epidendrum excisum in flower, Epidendrum excisum Same plant,#4 Epidendrum secundum., Maxillaria sp., Pleurothallis sp.and Odontoglossum lindenii ,Odontoglossum ramulosum, Odontoglossum ramulosum flowercloseup
With the different orchid types, it’s important to master the watering schedule. If orchids have pseudobulbs, enlarged stem structures that store water, the orchid potting mix can dry out a little between waterings. Orchid species that are epiphytes and grow on tree branches in tropical rainforests are adapted to receiving water from daily rain, so they need more frequent watering.  
Phragmipedium: Phragmipedium orchids are interesting in that they are one of the few orchids to produce vibrant flowers in an intermediate environment. You see, normally it is the extremes of climate that produce the most interesting colors. But this type of orchid is great for you if you have a temperate and mild climate but desire bright blossoms.
The Lycaste orchid genus, similarly to its relative Anguloa, likes intermediate-to-bright light, intermediate-to-cool temperatures, and high humidity. The flowers look rather different, though; they are more-or-less triangular in shape because the sepals point outward while the petals point forward. These orchids are very fun to grow, and will thrive if you get their care right.
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 Bulbophyllum orchid genus is the largest in the Orchidaceae family, with over 1800 species, making it the third largest genus of plants. (Taxonomists will probably eventually split it into several smaller genera, but with so many types of orchids it's a massive undertaking!) They differ widely in appearance, but all have a single leaf emerging from the top of the pseudobulb, flower stems coming from the bottom of the pseudobulb, and a hinged lip designed to tip insects against the column. Many are pollinated by flies, and stink like dung or rotting carcasses, which is a great conversation starter and gives you bragging rights for putting up with it! (They don't all stink, fortunately.) The rhizomes wander all over the place and often branch freely, so it's easy to grow an impressive specimen.