The next time you ponder the dark dots in a dish of vanilla ice cream, consider this: Each speck is actually an orchid seed, one of hundreds of thousands housed in the fruit, or "bean," of Vanilla planifolia. Native to the West Indies, vining V. planifolia is just one of an estimated 25,000 orchid species in the highly evolved and diverse Orchidaceae — the world's largest flowering-plant family, larger even than the grass family. It includes almost 800 different genera, one or more of which are indigenous to every continent except Antarctica.

Orchid family members can be as tall as 25 feet (Grammatophyllum speciosum) or as small as a thumbnail (Platystele johnstonii); some grow in the ground, others grow on trees as epiphytes, and a few are vines. The one trait all orchids share is their unique flower structure. In each bloom, three stamens (the male parts) and three pistils (the female parts) fuse together on a single column, or gynostemium.

Next: Growing Orchids

Photographs by John Glove