Orchids comprise one of the most abundant and varied of flowering plant families. There are over 20,000 known species and orchids are especially common in moist tropical regions. Although temperate orchids usually grow in the soil, tropical orchids are more often epiphytes which grow non-parasitically on trees.
Orchid flowers vary considerably in shape color and size, although they share a common pattern of three petals and three petal-like sepals. The lower petal has a very distinctive appearance.