What's So Special About Orchids?

The beauty and diversity of orchids have fascinated people for ages. As long as 5 centuries before Christ, Confucius compared the pleasure of seeing good friends to entering a room full of "lan" or fragrant orchids.

While the Chinese called these flowers "lan", the name they came to be known by in the western world was given (according to legend) by Theophrastus, a student of Plato. He noted the round paired bulbs of one common European orchid and gave it the name orchis from the Greek word for testicle.

Later, this name was applied not only to one genus, Orchis, but also to the entire family (even though the majority of orchids do not have this kind of root). Commonly this family is called the orchid family: scientifically, the family is called Orchidaceae.

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Medieval European herbalists believed that the shapes of plants indicated their uses to man. Since the bulbs of common European orchids looked like testicles, aphrodisiacal powers were attributed to them. Dried and pulverized tubers were used in love potions. It was believed that potions made from the younger, firmer tubers would encourage the conception of male children, while potions made from the older, softer tubers led to the birth of female children.

Orchids also evoked other images. Jacob Breynius, a 17th century German botanist, described them in an almost poetic way: "If nature ever showed her playfulness in the formation of plants, this is visible in the most striking way among the orchids. They take on the form of little birds, of lizards, of insects. They look like a man, a woman, sometimes like a clown who excites our laughter. They represent the image of a lazy tortoise, a melancholy toad, an agile, ever-chattering monkey. Nature has formed orchid flowers in such a way that, unless they make us laugh, they surely excite our greatest admiration."

Vanilla, the only widely used commercial product of the orchid family, was first discovered by the ancient Aztecs in Mexico. The vanilla plant was introduced to English gardens in 1739, and is credited with the increasing popularity of orchids in horticulture.

In the 19th century, orchids were in such demand that auctions in Liverpool and London attracted much publicity. Prices soared, with buyers often paying 500 pounds for a single plant. Top prices were much higher.

Because little was known of the growth requirements of these bizarre, tropical plants, many extreme practices were tried. English gardeners felt that plants coming from the tropics (the so-called hot and humid countries) needed hot and humid conditions. They placed orchids in stove houses which were combinations of heavily-painted glass, coal fires, and hot brick flues. There was no ventilation, and the bricks were drenched continuously with water to produce a steamy atmosphere. This was the beginning of the hothouse treatment which has so long been associated with orchids.

Under such extreme conditions, orchids quickly succumbed by the thousands. One nobleman remarked that England had become the "grave of tropical orchids". In spite of the speed with which orchids died, they were imported in ever larger quantities. The startling beauty of the flowers on the few plants that survived stimulated the desire to continue to cultivate them.

Competition was keen among aristocratic 19th century orchid culturists. The more successful growers carefully guarded their secrets. One of the first to successfully build up a large collection of exotic orchids was William Cattley of Barnet, England. The popular Cattleya orchid genus was named for and dedicated to him.

European scientists, too, were interested in orchids. Charles Darwin was fascinated by them. His studies into fertilization mechanisms in this family led to a 2-volume classic in 1862, The Various Contrivances by which Orchids are Fertilised by Insects .

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With so many people interested in orchids, one may well ask what is so special about these plants. One thing is the incredible diversity. There is simply no such thing as a typical orchid.

The Orchidacae is probably the largest flowering plant family. So far, approximately 30000 wild species have been described. Also many, many man-made hybrids have been created.

Orchids range in size from plants only an inch high with very tiny flowers to vines up to 50 feet long with flowers a foot across.

Orchids are herbaceous (non-woody) perennials that occur as vines, shrubs, and grass-like plants. Some bear a single flower; others have many flowers. They grow in habitats from tropical rain forests to alpine meadows, from bogs to semi-desert areas and from sea level to 14,000 feet in elevation. At least one orchid is semi-aquatic, holding only its blossoms above the water surface. Another species grows and blooms entirely below the ground.

Most tropical and subtropical orchids (the ones most grown by hobbyists) are epiphitic; that is, they grow on the trunks and limbs of trees. They ARE NOT parasitic upon the trees, but use the trees for perches. This allows the orchids to get more light than they would receive on the forest floor.

The largest, showiest, and most bizarre orchids occur in the tropics. Flower colors range from pure white to vivid pinks, lavenders, reds, golden-yellows, oranges, browns, and even blackish-purple. They vary from soft-muted tones to pure brilliant colors, and from solid shades to bizarre multicolored patterns.

Odors vary from orchid to orchid and range from the delicate spicy fragrance of vanilla to offensive smells of decay. Some orchids have no scent at all. Some are scented at some times of the day or night, but not at others.

Orchids native to temperate and arctic regions usually grow in soil or leaf litter. They generally have tuberous or bulbous roots which store moisture and nutrients. From these tubers, which are protected by the soil from freezing temperatures in the winter, new growth sprouts each spring.

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It is the orchid flower, despite its great variability, that allows us to identify the plant as an orchid. Even with its apparent complexity, the basic shape of an orchid is simple. Three sepals and three petals constitute an orchid flower. The showiest part of many orchids, the lip, is simply a highly modified petal. The column, which contains the reproductive structures, is often concealed by the lip.

Three sepals, the outer row of petal-like structures, serve to protect the flower when it is in the bud stage. While sepals often remain green in other flowers, in orchids sepals change from green to colors such as white, lavender, yellow, or a combination of colors when the bud is ready to open. In some species the sepals are not as wide as the petals and are easy to distinguish from them. In others, petals and sepals are very similar in size and shape. The topmost sepal sometimes forms a cap or helmet-like structure.

Three petals make up the inner parts of the blossom. Usually the lowest petal is distinctly enlarged, forming the lip. This structure develops strikingly handsome shapes and may be marked by spots of color in streaks, splotches, or very intricate designs.

Some orchids, such as paphiopedilums or lady-slipper orchids, have no lip. Rather, two of their petals have fused and combined to form a pouch which resembles the toe of a lady's slipper.

Inside the petals, and often concealed by them, are the reproductive structures of the flower. In orchids, these structures are fused together into one fleshy column. The column is unique to orchids, and does not occur in any other plant family. Located at the top are the male structures, including anthers which produce the pollen. On many orchids, the pollen grains are grouped together in masses called pollinia. These pollinia or pollen wafers are sticky and adhere to visiting insects.

Directly below the anthers, separated from them by a thin membrane, is a part of the female portion of the flower, the stigma. The stigma consists of a sticky surface upon which the pollen must be deposited to fertilize the flower. In spite of the close proximity of the male and female organs in the blossom, practically all orchids are cross-pollinated. The pollen packet is attached to a particular spot on an insects body and adheres to the stigma of the next blossom it visits.

At the base of the column, below the sepals, is the ovary. In the ovary, the ovules and eventually the seed develop. The ovary also acts as a stem to connect the blossom to the plant.

In most fully-opened orchids, the lip hangs below the other two petals. In the unopened bud, however, it is often above them. These buds twist 180 degrees just before they open. This motion is very important. It facilitates pollination by placing the lip at the bottom of the blossom as a perch for visiting insects to alight on. In some orchids the lip has raised structures for an insect to grasp.

The main function of all the attention getting shapes, colors, and scents of orchids is to attract insects and other animals capable of fertilizing the flowers. Among reported pollinators are not only bees, butterflies, wasps, and a variety of other insects, but also birds, frogs, and snails. Pollinating mechanisms are remarkably intricate, and many orchid species can be successfully pollinated only by a particular species of insect.

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Depositing pollen on the stigma triggers a series of profound changes in the orchid blossom. Soon the flower begins to wilt and change in color. Pollination stimulates the production of hormones which induce the immature ovules to ripen. Pollen tubes germinate from the pollen grains and grow towards the ovary. This growth proceeds slowly, and there may be a considerable time lapse between pollination and fertilization of the ovules.

After fertilization, the seed capsule enlarges and develops. Each mature seed is exceedingly small, usually only about a millimeter in diameter, and contains little food material. The small size is more than balanced by the vast number of seeds produced.

Since the tiny seed has so little food reserve, propagation of orchids by seed is a risky matter. A seed that lands on a suitable growing surface may germinate and develop into a tiny structure that resembles a corm, or underground stem. The seedling may remain in this state for as long as 24 months.

Before it can develop any further it must be infected by one of several species of fungus. The fungus penetrates the germinating seedlings, and eventually localizes in the roots. Because these fungi are found in the roots they have been called mycorrhiza from the Greek words for fungus and root. A symbiotic relationship occurs between the orchid seedling and the fungus, each depending on the other for materials that they cannot make themselves.

If everything goes well, the orchid will continue to grow and eventually will bloom. The development from seed to flowering plant can take as long as 7 to 10 years, or as little as 20 months.

Artifical methods of propagation have been developed to make orchid plants a viable nursery crop. By having orchid plants widely available at reasonable prices, this onetime hobby of the very rich or very dedicated is within easy grasp.