Oncidium

Native: a genus that contains about 330 species of orchids; widespread from northern Mexico, the Caribbean, and some parts of South Florida to South America; usually occur in seasonally dry areas
Type: most species are epiphytes, although some are lithophytes or terrestrials
Size: flowers are not large, but this is more than compensated for in most species by the great numbers of flowers produced on long, often branched inflorescences
Colors: some have long racemes with small flowers and a dominant lip that are mostly golden yellow with or without reddish-brown barring, but some are brown or yellowish-brown; other species have white and pink blooms, while some even have startling, deep red colors
Growth pattern: sympodial with each new growth arising from the previous growth
Pseudobulb: have pseudobulbs with one to three leaves; there are several basal bracts at the base of the pseudobulbs
Roots: roots of most species are fine and numerous
Known for: name is derived from Greek word "onkos", meaning "swelling" referring to the callus at the lower lip; known as 'spray orchids' among some florists; most common variety is often referred to as Dancing Lady
History: first described by Olof Swartz in 1800
   
Oncidium

The petals are often ruffled on the edges, as is the labellum. The labellum is enormous, partially blocking the small petals and sepals.

A complicated callus on the labellum distinguishes the Oncidium and can be used to separate the taxa. The presence of column wings is another Oncidium characteristic.