In the plant kingdom, it’s a daily fight for survival. Most pollinating plants depend on animals such as beetles, butterflies, birds and bees to successfully reproduce. With so much colourful competition, plants are forced to concoct unique methods to guarantee their pollen is collected and transported. But there is one plant family which has become especially adept at deceiving pollinators – an essential skill given how some are exclusively pollinated by a single pollinator species – and that’s the orchid (Orchidaceae).
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As Kew celebrates the return of its popular orchid festival, this year taking inspiration from the spectacular biodiversity of Peru, we’ve asked Kew scientists to share some of the most masterful techniques orchids use to lure pollinators in the fight to survive.
“Orchids have long been popular houseplants – they are the jewels of nature,” says Arnau Ribera Tort, Kew’s Collections Support Officer. “But their beauty comes with a complex ecology: they depend on specific fungi and pollinators to survive, making them especially sensitive to changes in the environment. This has put the orchid family at even higher risk of extinction than most plants, with an estimated 56 per cent of species under threat according to RBG Kew’s State of the World’s Plants and Fungi 2023 report.”
Orchids disguise themselves as pollinators
The bee orchid (Ophrys apifera) features several small flowers, each of which has three large, pink, petal-like outer tepals, a large lip (labellum; modified inner tepal) resembling the body of a bee, and two other inner tepals that look like antennae. The whole flower thus mimics an insect, and there are numerous examples of orchid flowers that resemble their insect pollinators.
In the UK, the bee orchid does not need to use its powers of deception because it is self-pollinating; the pollen drops automatically onto the female reproductive organ (stigma) and fertilises the flower. However, in other Ophrys species (in the Mediterranean region, for example), male bees or wasps are attracted to the flowers, which look and smell like the females of their own species.
Spider orchids (Brassia caudata) similarly use their shape. “What is peculiar about this orchid,” says Kew scientist Dr Oscar Alejandro Pérez-Escobar “is that when you look at the flower, it looks like a spider from afar” (hence the name). “A famous orchidologist, Calaway Dodson, hypothesised that a spider-hunter wasp pollinates this orchid by attacking the flower, thinking it’s trying to parasitise a spider. But in fact, when it attacks, it is completing the act of pollination.”
Some orchids smell like rotting flesh to attract flies
Kew’s Dr Carlos Martel has dedicated his research to the pollination techniques employed by orchids. Perfume orchids such as the Light Fox-Red Gongora (Gongora rufescens) are especially nifty, having evolved chemically based scents to attract only male orchid bees (Euglossini bees). “Like men looking for a new cologne, male orchid bees seek out these perfume orchids not to find food, but to cover themselves in the orchid’s scent which they use to stimulate females for mating.”
Alluring scent does not necessarily carry the aroma of a sweet perfume as the carrion-flower orchid (Satyrium pumilum) demonstrates. A particularly unpleasant smell of rotting flesh is favoured by this orchid to entice carrion flies to great effect.
Some orchids pretend to be a female pollinator
The female form is once again utilised by the hammer orchid (Drakaea elastica) which, like the bee orchid, uses its labellum to emulate the form and scent of a female thynnid wasp. But the hammer orchid takes things one step further to ensure the male wasp removes the pollen sacks (pollinia) – as the wasp attempts to mate with the flower, the labellum swings over, flipping the male onto the stigma where the pollen sacks are needed for pollination.
Orchids create nifty traps for pollinators
With its gloriously bulbous plants, bucket orchids (Coryanthes spp.) use their colourful flowers to trap orchid bees that have been attracted to the heady scents of its aromatic essential oils. Within its fluid-filled bucket, the orchid offers flailing bees only one escape – a route lined with pollen sacks (pollinia) that the fleeing bee inevitably comes into contact with.
Be they con artists, catfishes or cheaters, there’s no denying these orchids are absolute masters of pollination. And they do it in style.
Orchids runs from 1 February to 2 March 2025 at Royal Botanic Gardens, Kew, London