Although there are already more than 25,000 species of orchids, scientists are consistently discovering more. Because orchids are bilaterally symmetrical, much like a human face, some feel that they are naturally attractive to humans. Likewise, humans' taste buds also are attracted to the vanilla plant, a type of orchid. Many insects are even more attracted to orchids, sometimes mistaking them for mates.
Despite the tens of thousands of varieties of orchids, the number continues to increase because horticulturalists hybridize different types of orchids to create new species. Scientists also expect that more types of orchids are still undiscovered in tropical areas.
Research indicates that some types of orchids are as old as 120 million years old, which means orchids may have existed even before Pangaea split into separate continents. Because there are species of orchids that are closely related genetically even though they grow thousands of miles away from each other, researches speculate that continental drift separated these varieties.
Because many types of orchids have flowers that have the same shape and color of the insects they want to attract, insects are often tricked into thinking that the flower is actually a potential mate. When this occurs, pollen adheres to the insect, which then carries it to another orchid.