The Orchidaceae family contains 800 to 1,000 genera and an estimated 15,000 to 20,000 orchid species. Many orchids seen in stores today however, are not true wild species but horticultural hybrids. Most orchids actually grow as epiphytes on plants. The vast majority of orchids also have only a few bee species that act as a pollinator. Because of this, orchids are relatively depauperate on islands. Not only does the orchid have to reach the island, a rare event in itself, but at the same time, the insect must reach the island. Such a probability makes island orchids almost non-existent. For example, on the Hawaiian Islands, which are the most isolated islands on earth, there are only two native orchids. Both are generalist orchids, with no specific pollinator.
Orchids are also quite important for horticulture and for the spice trade. Many varieties and hybrids are bred for their beauty and displayed in the home. One species, Vanilla planifolia or vanilla, is an unusual orchid as it grows as a liana (a long vine) up the sides of trees.
Systematics: Orchids have a perianth of 6 tepals in 2 whorls of 3. They usually only have 2 stamen and a single pistil. In the Orchidoideae the pollen is given as packets in modified areas of the flower.
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