Often people consider orchids to be aristocrats among flowers. However, it would perhaps be better to compare them with queens. There was a time when orchids were mainly valued in prom or the opening night wreathes as well as in the form of interesting displays in botanical gardens or conservatories. However, these days, orchids are no longer considered royal and are commonly found in nurseries, florist shops as well as on the shelves of supermarkets and discount stores.
There are orchid societies across the world and they organize shows as well as sales in shopping malls and various other venues. Moreover, these days it is possible to buy an orchid for the price of an azalea (any shrub belonging to the genus Rhododendron). In this case, familiarity does not give rise to disdain, but offer new challenges and endeavours, as new gardeners or even converts realize that growing orchids is surprisingly easy.
Some of the most common orchids include cymbidiums, cattleyas, paphiopedilums (also called lady's slipper orchids) and phalaenopsis. However, various other types of orchids are also gradually gaining in popularity. These include dendrobiums, masdevallias and miltonias. Aside from these orchids, there are innumerable others that can contribute to the variety of your collection.
There are several thousands of orchid species and together they comprise a remarkably wide-ranging family. The appearance of several orchids is so different that it is difficult to believe that they belong to the same family. Despite their amazing shapes, sizes and the proportion of their different parts, orchids have certain traits that are common and help one to differentiate them from other plants.
From the botanical point of view, orchids are perennially growing plants having zygomorphic or irregular shaped flowers. In other words, different from a rose or even a camellia blooms, which are divisible in equal halves in any of their several planes, it is only possible to divide the flowers of orchids into two equivalent halves just in one plane. Orchid flowers usually comprise three external segments or sepals and three inner sections or petals. One petal of these flowers is highly modified in its form and is known as the labellum (lip).
The reproductive organs of an orchid flower are centered in an area that is called the column. An orchid flower has several extremely complicated structures, comprising the column and the lip. The purpose of this is to make sure that the pollinating agents, such as bees, beetles, flies and birds transfer the pollens of one type of orchid flower to the flowers of the same type of orchids, thereby putting off self-pollination as well as cross-pollination with different species.
Orchid flowers have several modifications in their structure. In some flowers, the lip or labellum may be extremely reduced or enormously enlarged, while the petals may be reduced to such an extent that they almost become invisible. Similarly, one or several parts of a flower may be extended into elongated tails or even be fused. Such abnormalities as well as the complicated structure of the flowers contribute to their extraordinary beauty. It is, therefore, not surprising that in many cases weirdly beautiful flowers of other plants are also wrongly thought to belong to orchids.
You can find orchid flowers in almost all hues, except in true black. While the markings found on Coelogyne pandurata flowers have an inclination towards true black, but the main colors of orchid flowers include lavender, white, yellow, red and pink. You will rarely find an orchid bearing pure blue flowers and, therefore, such flowers are highly esteemed. On the other hand, green and brown are common colors of orchid flowers and several orchid species bear flowers that are marked with one or additional contrasting hues. Zygopetalums is an orchid species that bear very aromatic flowers and usually have green-and-brown petals and sepals, while their white lip has tinge of purple.
The size of orchid flowers may also vary greatly. While some flowers measure almost a foot in diameter, there are many that are just the size of pinheads. Similarly, the aroma of many orchid flowers is fresh and fruity, while there are others that have a sultry and exotic fragrance.
The growth habits of orchids are as varied as their blooms. There are several orchids that grow on trees, while many grow on rocks. Orchids that survive on rocks are called lithophytes, while those that grow on trees are known as epiphytes. These orchids survive on rain as well as the nutrients carried to them by decomposing leaves and various other organic materials. It is important to note that though many orchids grow on trees, they are not parasites. They simply live on trees and never draw their required nutrients from the trees on which they grow.
Aside from growing on trees and rocks, many orchids subsist in the soil and they are called terrestrials. This type of orchids may have fibrous roots, tubers or even rhizomes. Very few of them do not contain any chlorophyll and survive in the form of saprophytes on decomposing plant materials in the soil. This type of orchids is not found in cultivation. Some of the orchids that we are familiar with may be great opportunists and occasionally live in the space inside leaf molds found on rocks. Alternatively, they may also be found in the tree crotches. Occasionally, this type of orchids may also be found thriving on the ground, especially in fertile, greatly organic soils.
Orchids enhance their size in two different ways. Plants that have monopodial growth (growing upwards from one particular point) usually grow taller every year as a result of new growth that only forms at the stem tips. The leaves of such orchids are arranged in two rows on opposed sides of the vertical stem. Precisely speaking, each leaf alternates with the one growing on the opposite side, forming a sort of partnership. The flowering spikes as well as the aerial roots develop opposite a leaf or within a leaf joint. Such growth may result in the stems becoming taller like in the case of the species called Vanda, or they may remain so small that they are almost invisible like in the case of the species belonging to Phalaenopsis. It is worth noting here that in case the top growth of these orchids is damaged somehow, they will still continue to produce fresh growths from the lower buds that were dormant so far.
Aside from this type of lateral growth, some orchids have sympodial growth (new growths from a somewhat horizontal stem). In fact, sympodial growth is by far more widespread among orchids. In this case, the plant stops growing vertically. In majority of cases, after the plant has grown for one season, the growth in the next season emerges from the base of the previous year's growth, thereby enlarging the plant laterally. Sometimes, the growth is also vertical provided the orchid is being nurtured on a vertical surface. Usually, orchids having sympodial growth may bear flowers from their tips of their latest growth, from the buds on previous growths or even from the plant's base.
Several orchids having sympodial growth develop condensed or thick stems known as pseudo bulbs. These pseudo bulbs store food and water for the plants, enabling them to stay alive even during droughts. You can find pseudo bulbs in various forms - flattened, round and fat, or drawn out into cylindrical stems that are generally referred to as canes. The size of the pseudo bulbs may also vary - ranging from microscopic to several feet long. The leaves of such orchids may develop the length of the pseudo bulbs or from the tip of the pseudo bulbs.
Orchids are found growing in a wide variety of places and habitats. You may find some terrestrial variety of orchids growing even north of the cold Arctic Circle. However, most of them grow in places having temperate climatic conditions in North America, Europe and Asia. In fact, many terrestrial orchids are found growing in places having climatic conditions similar to that prevailing in the Mediterranean region, such as the Mediterranean basin, South Africa, Chile and many regions of Australia. Several such orchids have a propensity to grow as well as bloom during spring and winter. These orchids rest as tubers during the dry months of the year.
In places where the winters are very cold, terrestrial orchids spend the entire winter in a dormant stage as rhizomes or tubes. They start growing rapidly in spring and summer and bear flowers as well as set seeds. It is very difficult to grow terrestrials in such places in North America and, hence, you can rarely see them as garden plants.
On the other hand, epiphytic orchids or those that grow on trees are mainly found in the sub-tropical as well as tropical regions. However, one epiphytic orchid, called Epidendrum conopseum, is found growing in places very far north like California, while many Asiatic orchid species may be found growing northward to Japan. Contrary to the belief that orchids are jungle plants, they are rarely found in dark, damp undergrowths. Majority of the epiphytic orchids grow quite high on trees, much above the ground, where they can get plenty of sunlight. Alternatively, they can also be found growing in the pebbly ledges in open fields as well as the edge of forests. Several orchids are found surviving in places receiving seasonal rainfall and, as a result, they have evolved systems to preserve moisture.
You can find several species of epiphytes in Australia and Africa. However, many more are found in south-eastern Asia, tropical America and the various islands of Indonesia. In all these places, epiphyte orchids can be found growing right from the sea level to the upper reaches, from the coastal forests and scrub woodlands that experience seasonal dry spells to eternally humid mist forests located at higher altitudes. Perhaps, epiphyte orchids have the maximum concentration in the mountainous regions of New Guinea as well as the mountainous regions of Colombia, Costa Rica, Ecuador and Peru. Hence, it is obvious that all species of orchids will not grow in any particular growing conditions.
It is important to note that it was necessary for both lithophytes and epiphytes to get used to very different conditions in order to receive a regular supply of nutrients - foods and drinks. Several epiphytes and lithophytes have pseudo bulbs. Majority of them also bear thick and succulent leaves having a waxy surface that slows down water transpiration. Some orchids shed their leaves when they are in a resting or dormant stage. During this period, these orchids wait for rains to restart their growth.
In fact, epiphytic orchids have roots that are adapted in a manner that they are able to collect as well as conserve moisture. The roots are chunky with very less branches and are covered by a spongy or velvety layer called velamen. This spongy layer comprises several cells which fill with air when the roots go dry. However, they eagerly absorb moisture again when there is rain or the moisture present in the atmosphere and conserve them for a prolonged period.
Aside from hauling out nutrients and water, the roots of all epiphytic orchids also possess the ability to secure the plants on the tree branches they grow. These roots can tie up onto any support that may be available, thereby gripping the cracks in the tree bark or firmly clutch onto permeable ceramic pots.