Orchids

The sheer volume of Orchidaceae, possibly the largest family of flowering plants, can be a little confusing at first. It does not take long however before you can enjoy the satisfaction of distinguishing between Paphiopedilum and Cymbidium.

General facts

The orchid family includes nearly 900 genera, somewhere between 20,000 and 30,000 species and over 70,000 hybrids or cultivars.

The largest number of orchids, and often the most popular, come from Asia. This is the home of the Paphiopedilum, the striking lady slipper orchid. South America is also especially rich in wild orchids, but really they can be found in any conditions almost anywhere except the polar regions.

Groupings

Orchids can be grouped according to their growth habits and roots. These are not taxonomic classifications, but helpful guidelines to understanding their evolutionary adaptability and care requirements.

Orchids have two main ways of growing. In monopodial growth, there is one, usually upright growth axis from which the leaves appear. In sympodial growth, the growth axis is a prostrate rhizome which sends off shoots. Many sympodials develop pseudobulbs, which are thickened shoots from which the leaves grow. Pseudobulbs act as storage organs for water and nutrients.

Within these two broad groupings, orchid types can be narrowed down further to these four groups:

Terrestrial orchids have their roots in soil. Terrestrial roots resemble those of other plants.

Epiphytes are the climbers. In their natural habitats they are found in the treetops, their roots clinging to the tree and supporting them, and absorbing nutrients and water.

Lithophytes are orchids that grow on rocks or in very little soil. Both epiphytes and lithophytes have aerial roots which are thick and fleshy, resemble snakes, and are covered with a spongy, silvery crust called velamen that adds to their other-worldly look. Velamen is a protective substance that attracts and retains humidity and fixes the roots to their home. It also serves as insulation against ultraviolet radiation and contains chlorophyll to assist in photosynthesis.

Saprophytes do not get much attention because they are virtually impossible to cultivate. Saprophytes derive their nutrition from dead or decaying matter through symbiotic relationships with fungi. Some of the world's largest orchids are of this type, such as the genus Galeola, whose stems can reach 20m in a matter of days.

History

The earliest references to orchids can be found in Chinese literature dating back to 800 BC. Later, around 500 BC, Confucius himself celebrated the fragrant cymbidium because he found its subtle yet seductive smell to epitomise the characteristics of an ideally virtuous person: strong in one's belief but gentle in one's approach.

References in antiquity continue, through Japan, through Greek and Roman history and dotted throughout other cultures until the mid-18th century. By this time the European passion for going forth and classifying the whole of nature combined with the driving forces of colonialism to create an all-round fascination with the unknown. The orchid really started to take off in European society because it came to symbolise the beauty and the danger of far-off lands of mystery.

Although the first tropical orchid to flower in Europe came into bloom in 1733, it was actually the accidental discovery of cattleyas that started the real craze for orchids. A plant enthusiast named Cattley had received some plants from Brazil which had been wrapped within other plants with thick leaves for protection. When these throwaway plants produced their first flowers, Cattley, and soon the rest of English society, were stunned and thrilled. Botanist John Lindley, who came to be known as the father of orchidology, named the plant Cattleya labiata, in respect of the accidental discoverer and the gorgeous labellum of the flowers.

Orchids became one of the ultimate luxury items and status symbols of Victorian times, and collectors displayed an unparalleled obsessiveness. Plant hunters were commissioned and sent all over the globe; many of them met gruesome ends, and patrons often seemed more concerned that the plants get home safely rather than the plant hunters themselves.

In the mid-19th century botanists met with hybridising success, but it was not until propagation from seed was finally cracked that people finally stopped paying outrageous prices (prices that could buy a house) for these remarkable flowers.