So many of these flowers are stunningly beautiful, while others are quite bizarre looking. But just think: These natural creations that are so attractive because of their beauty or their complexity are the result of adaptations to the way they are fertilized by insects or birds and proof that they have evolved in close step with these pollinators.
Let’s take a look at how orchid flowers have evolved by developing one or more features that allow them to attract pollinators.
Methods used to attract pollinators
Unlike many other groups of flowering plants, orchids are not pollinated by wind or water. With the exception of self-pollinating ones, especially certain terrestrial species, they are pollinated mostly by animals, mainly insects. While helping to ensure the continuity of the species, insects contribute actively and more quickly to genetic selection and recombination than simple cross-pollination ever could.
The main orchid pollinators are bees and other Hymenoptera, some flies and hummingbirds. Two methods are used to attract these pollinators: signals and rewards. The insect (or bird) must see the flower and recognize it. The flower attracts it with its shape, colour and scent. The insect must receive a reward, though, that will tell it to visit another flower.
The goal: pollination
“The object of the following work is to show that the contrivances by which Orchids are fertilised, are as varied and almost as perfect as any of the most beautiful adaptations in the animal kingdom; and, secondly, to show that these contrivances have for their main object the fertilisation of each flower.” (Darwin, 1862)