Dr. T. Ombrello - UCC Biology Department

CATTLEYA ORCHIDS

Common name: Florist’s Orchid

Scientific name: Cattleya hybrid

Explanation of scientific name:

Cattleya - named for William Cattley, an English horticulturist of the early 19^th century, who was an ardent collector and grower of rare plants.

Cattleya is a genus of the Orchid family (Orchidaceae), the largest family of flowering plants with over 500 genera and at least 35,000 species. New species are being discovered every year. Orchids have a worldwide distribution, but the genus Cattleya is restricted to tropical America. The Cattleyas are the best-known members of this family. They are the chief horticultural or corsage orchids and are the flowers one generally associates with the term “orchid”. There are about 50 natural species of Cattleyas, but they have been hybridized extensively since the 1850’s and thousands of hybrids are in cultivation. The Cattleya species have been crossed with each other and with members of other orchid genera, especially Brassavola and Laelia, and this has led to a wide diversity of flower form and color.

The Cattleyas are epiphytes or “tree dwellers”. They inhabit the branches of trees and sometimes barren rocks. They are not parasites of trees, since their nutrition is derived from the atmosphere or from decaying organic matter that accumulates on branches or in crotches between limbs. Cattleyas thrive in this nutrient poor and freely draining medium. The Cattleyas’ adaptations to their habitat include thickened stems for food storage called pseudo-bulbs, roots that cling to the substrate to hold the plant in place, and thick, leathery leaves that transpire little water.

Cattleya plants are long-lived perennials and will usually flower annually. Commercial growers maintain plants for 8-10 years before replacing them, and there are accounts of individuals living for over half a century in cultivation. Contrary to popular belief, they are not difficult to grow in the home. A very well drained soil, moderate light and temperature, judicious watering and an occasional dose of fertilizer are all they really need.

Cattleyas, as do all orchids, start off life in nature as tiny seeds within a seedpod or capsule on the mother plant. When the seedpod matures and splits open, millions of tiny seeds are released and dispersed by the wind. The seeds are well under 1/100 inch in length and 3 million of them weigh only one gram. Some pods hold over 4 million seeds. These dust-like seeds have little or no stored food, so in order for them to germinate and survive, they must fall on a suitable medium and come in contact with a microscopic fungus. The fungus converts complex starches in the environment to simple sugars that the orchid seeds can use for energy. Orchid growers have replaced the fungus with artificial mediums that supply the necessary nutrients. Hundreds of seeds can easily be germinated in a small flask.

The process of meristem cloning (tissue culturing) works very nicely with orchids, too. Cattleyas in particular are being vegetatively propagated in this manner. Tissue from the growing point of a single shoot can yield hundreds of identical plants in a matter of months. Conventional methods of asexual propagation would take many years to accomplish this. Meristem cloning is aiding hybridizers by producing many identical plants with which to make crosses. There are already more hybrids than natural species of orchids, and our fascination with the breeding of these plants will probably lead to an almost unimaginable variety of types in the future.