Wikipedia
Tolumnia Rafinesque, is a genus in the family Orchidaceae. Previously known as the "equitant Oncidiums," the species were segregated from the mega-genus Oncidium by Guido Braem in 1986. The plants are small, usually epiphytic, with small or absent pseudobulbs completely covered by leaves, which are triangular or circular in cross section and overlap each other at base to resemble a fan. The inflorescences arise between the leaf base and bear colorful, showy flowers. The labella are large, ornamented by variously shaped calli. The column bears prominent wings flanking the stigma. Dancing-lady orchid is a common name for some species in this genus.
The genus is primarily native to the Greater Antilles, with a few species extending into Florida, the Lesser Antilles, Mexico, Central America and northern South America (from Colombia to French Guiana).