They range in size from the very small to vines which are over 30 feet in length and some have flowers the size of footballs. Orchids naturally occur in all colours except for black and no one has, to date, been able to produce an orchid with an all-black flower. In temperate climates they tend to grow on the ground. In tropical climates they tend to grow on trees or other plants but they are not parasitic in that they draw no nourishment from the host. These orchids are called epiphytic.
Some orchids are lithophytes which means that they grow on rocks.
Orchid Pollination Orchids reproduce by cross-pollination with birds, insects, and other animals carrying pollen from the stamen of one orchid to the pistil of another. Cross pollination between different plants, rather than self-pollination, has helped orchids evolve and adapt to their environments. Orchids have evolved some of the most complicated pollination systems of all plants. One of the most famous orchids in the scientific world is the Angraecum sesquipedale of Madagascar. Though he was ridiculed he turned out to be right as, after his death, its only pollinator was discovered.