The short answer: pollination. Orchids have evolved a huge variety of pollination strategies. While most flowering plants use bright colors, fragrant scents, or nectar rewards to attract pollinators, many orchids exploit the pollinator’s need for mates or nesting sites instead. The result is an awesome diversity of flower shapes, colors, patterns, and chemical cues. In a jungle filled with fragrant showy flowers, how do you stand out from the crowd?
This week I will highlight just a few of the super cool pollination strategies used by orchids, illustrated by yours truly.
1. Sex Appeal
Many orchids are sexually deceptive, meaning the flowers mimic female wasps. These flowers are shiny, furry, patterned, and some even have eyespots. Almost all known species of sexually deceptive orchid come from Europe and Australia.
In addition to mimicking the looks of a female wasp, these orchids also produce the chemical compounds that mimic the pheromones used by wasps. Female insects produce chemical signals comprised of blends of volatile compounds. The chemical identity and relative concentration of chemicals act as species-specific signatures. Amazingly, sexually deceptive orchids have evolved to produce compound blends with remarkable similarity to the wasp’s pheromones.
The Mediterranean orchid species, Ophrys mammosa, uses both visual and chemical cues to attract the male wasp, Andrena fuscosa. The female’s velvety body with reflective blue pattern and shiny blue eyes are part of the orchid’s flower.