Orchids are among the most diverse species in the plant kingdom. Not only are there over 1000 natural species of orchids, but hybridization has added to their numbers and variety. In fact, once orchids became known in Europe and North America, the frenzy of breeding new species has produced over 100,000 different kinds. However, regardless of their numbers, basically orchids grow in two types of situations – epiphytic or terrestrial.
Epiphytic orchids are most usually found in tropical or semi-tropical regions such as South East Asia, Polynesia, India, and South America. Unlike most plants, which root themselves in the ground, epiphytic orchids depend on trees for both support and nourishment. Epiphytic orchids are not parasitic on their support, they draw no food from the tree on which they are living, they simply need the proper place on which to establish themselves. Most epiphytic orchids prefer to live halfway between the forest floor and the upper canopy, where they will receive diffuse sunlight, good air circulation, and the humidity they require for proper growth.
Mature trees in the tropical and subtropical regions collect a great deal of debris on their limbs and at the juncture of their trunk and branches. It is in this debris that epiphytic orchids live and from which they draw nutrients. This debris is vital to these orchids, because if an orchid seed lands on a bare branch, it will not germinate. These large trees are true hanging gardens as they become covered with orchids and other epiphytic plants.
Although they have no cold winter season, tropical regions do have wet and dry seasons. Rain is greatly restricted during the dry season, but epiphytic orchids have found the way to cope with this lack of moisture. To enable them to survive the dry time, epiphytic orchids have developed pseudobulbs, which are actually swollen stems, which can store water. The roots of these orchids have also adapted to allow them to take in water and dissolved nutrients quickly, which is especially important during the only occasional rain of the dry season.
Some of the spectacularly flowered orchids are epiphytes such as Phalaenopsis, Cattleyas, and Dendrobiums. These orchids, especially the Cattleyas, have also given rise to numerous hybrids. Because of the beautiful colors and shapes of these orchids, these are the ones most often seen used in women’s corsages. It was the adaptability of these orchids that allowed them to be transplanted and hybridized so easily.
While epiphytic orchids lack bulbs or corms, terrestrial orchids generally do have these structures. Even the roots of these orchids are fleshier than those found in tree-living varieties. While epiphytic orchids are most generally found in warmer regions, terrestrial orchids can be found almost anywhere, and some have even extended their ranges to the subarctic. Many of the terrestrial orchids from the temperate regions have small flowers, but the moccasin flower or Lady’s Slipper orchids are an exception in both their color and size. These orchids are often found growing in dry woodlands, and sport a large pink or yellow flower. Unfortunately, these orchids resist transplanting and are best left where found.