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.
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 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.  
Special thanks to David Banks of Australia, Christian Kirsch; Dr. Rudolph Jenny, Peter O'Byrne***, Eric Hagsater***, Lisa Thoerle***, Mario Blanco***, Mark Whitten***, Adam Karremans, Hakan Halander****; Daniel Jimenez***, André Schuiteman***, Dr. E.F. de Vogel, Jaap Vermeulen, Rick Barry, Dr. Guido Braeme, Rogier Van Vugt; Rene Dishong, Tom Ballinger, Mac & Helen Rivenback; Dr Rubin Salueda; Rafael Govaerts***, Padre Pedro Ortiz, Dr Leslie Garay, Vena Read, Charles Lamb, Donald Tan of Malaysia, Joseph Dougherty, Dalton Holland Baptista, Rick Cirino; Prem Subrahmanyam, ROMAN MARUSKA Czech Republic, Michael Coronado, Alejandro Taborda, Greg Butler and Oak Hill Gardens, Bill Bergstrom and Bergstrom Orchids, Donna Nash, Oliver Lenhard, D. E Vermeullen, Americo Docha Neto, Richard Korber, Carl Withner, Mark Nir, Ekkehard Schwadtke; Dr Eric Christenson, Dave Alford, Igor Zhuravlev, Tony Watkinson, David Hunt, Jean Marie Vanderwinden, Glen Ladnier, Jeffrey W. Tucker, Jorge Alejandro Paulete Scaglia, Scott McGregor, Wilella Stimmell, Eric Thiessen, Geert Volckaert, George and Kathy Norris***, David Alford, Eric Hunt, Peter O'Byrne, Allen Black, Helen Milner, Al Pickrel, Greg Riemer, Marcia Whitmore, Phillipe Musschoot, Wilford Neptune, Jean-Claude George, Tony Walsh, Greg and Kerri Steenbeeke and their Orkology Kreations Website, Jim Hamilton, Robert Fuchs and RF Orchids, Gene Monier and JEM Orchids, Jerry Bolce, Andy's Orchids, Stephen Jones, First Ray Orchids, Robert Weyman Bussey, JEM Orchids, Carlos Hajek and his Peruvian Orchid Page, Bill Morden, David Morris, Noble Bashor, Patricia Harding, Nina Rach, David Haelterman; Craig Cooper, Rocky Giovinazzo, David Friedman, Bill Pinnix, Troy C. Meyers, Linda's Orchid Page, Pierre-Alain Darlet*, Guy Cantor, Tropical Orchid Farm in Maui, H&R Nursuries, Lois Greer, Ichiro "Haru" Ohsaka and his Bulbophyllum Page, Mauro Rosim from Brazil, A World Of Orchids, Bruce Norris of Canada, Nick Doe, Neville De La Rue, Nelson Barbosa Machado Neto, Jeff Aguillon, Dale and Deni Borders, Eka Mulja Tjipta, Rick Barry, Manfred Schmucker, Uri Baruk, Mike and Candy Joehrendt, Dan and Marla Nikirk, Walter Orchard, Christer Carlson; Guillerrmo Angulo, M. Max, Paula Vagner, Tennis Maynard, Greg Allikas, Malcolm Thomas, David Morris, Jacques Deschenes, Lourens Grobler; Gary Yong Gee; José Castaño Hernández; Judd and David Janvrin* for their photo and text contributions.
Epidendrum orchids are among the oldest genera in the orchid taxonomy. Originally, this genus included all epiphytic orchids. As knowledge of the different types of orchids expanded, the classification became much more refined; for example, there are now some terrestrial species in the Epidendrum genus, and a great many other species have been moved to other genera. Still, over 1000 Epidendrum species exist. They are usually easy to grow, and most have tall canelike pseudobulbs that lean all over the place and frequently produce keikis. Fun orchids!
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.  
There are over 60 varieties of the Vanilla orchid, and unfortunately, it only blooms for one day, opening in the morning and closing at night. They grow in clusters of 12-20 buds, and they are yellow-green in color and reach approximately six inches in length. Just like their name suggests, you can actually get vanilla from these flowers, and the blooms have a nice vanilla scent as well. They have to be mature in order to flower, which can take two to three years, and they grow up to ten feet in height. They do best in a garden or a greenhouse, but never as an indoor plant, and they need vertical support to grow and thrive.
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.
Orchid stems are also specialized into what are called pseudobulbs. These are basically expanded stems that allow the plant to store excess water and food. The roots of epiphytic (tree-dwelling) orchids have a special outer layer of dead cells called velamen. Because orchids metabolize slowly in order to not outpace their resources, the roots also absorb slowly, meaning that they need help catching water as it passes by. The velamen cells catch and fill with water as it passes by so that the true root (the core of the root structure) has ample time to access as much water as it can. Velamen is silver-white in color, but becomes transparent when wet, so that when the root is wet it turns green as you are able to see through to the inner structures of the root that contain chlorophyll.
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.
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.
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