The genus contains approximately 500 species. The most common flower colours are combinations of yellow and brown, although lavender and white are colours not infrequently seen in the genus. The individual flowers are not large but this is more than compensated by the great numbers of flowers produced on long, often branched flower spikes, producing a "Shower Of Gold" effect. A diagnostic feature of the flowers is an often ornate, complicated callus or `crest' at the base of the lip. This can range from a toothed protuberance to a shiny, warty structure. In fact, the genus takes its name from this feature, Oncidium being derived from the greek word for a tumour or swelling. Naturally, this feature serves in pollination.

The majority of species have rather prominent pseudobulbs and strap-shaped thin leaves. Flowers are produced from the base of the plant in the axils of the sheathing leaves. Most species are epiphytic, growing on trees, although a few grow on rocks. The roots are fine and numerous.

CULTURAL REQUIREMENTS

Majority of Oncidiums thrive in good, strong light (short of burning ), coupled with adequate fertilizer and good roots, will result in robust in inflorescences,. The leaves should be a medium green to slightly yellow, never, dark, glossy green.

Temperature And Humidity

Oncidium grow in different habitats depending on the species. While Oncidium are more accommodating in their temperature than many orchids, the various species will do best if grown for at least a good part of the year in temperatures approximating those in their native habitats. Majority of species will grow well in temperature between 25-30oC during daytime and 20oC during the night.

Watering

The watering schedule for Oncidium is similar to that for Cattleyas although some species require slightly more frequent watering in order to keep the most recent pseudobulb drying and shrivelling.

Fertilizing

The fertilizer requirements of Oncidium are similar to those for most other epiphytic orchids.

Potting

Oncidiums initiate new roots, often in large numbers, during active vegetative growth. This shows that the proper time to repot is just after new growth begins but before tender developing root tips can be broken. They should be repotted every second year. Oncidium grow well in most standard epiphytic orchid potting media. However, it is essential that drainage be perfect.