There is no better place in the virtual world at this time of year than orchid social media. #Wildflowerhour on twitter on a Sunday evening is full of Irish and British orchids in flower from May to July. These flamboyant and deeply sexual plants are master manipulators of other organisms. Indeed, human fascination with orchids extends to books, art and music .
Being hyper attractive to humans can be a blessing or a curse. By bringing too much attention to yourself you might end up being collected and the population decimated, or heightened awareness may lead to a greater appreciation of wild nature and better management of orchid rich habitats. Orchid rich dry grasslands in calcareous (chalky) soils are a high priority for conservation in Ireland and are one of the jewels in the floral crown of the Burren.
Many of our 30 or so species of native orchids are certainly attention-grabbing. They can be found in the most unlikely of places, with the highly distinctive bee orchid found in disturbed road or rail verges, old quarry pits, and even on the hard stand of a wind turbine!
Not only do these orchids look like fuzzy bees, a passing male of the right species also gets a whiff of a powerful chemical pheromone that smells even better than a female bee. Enchanted by this perfumed lady-bee mimic he zips down to attempt to mate with her and in the process gets a neat package of pollen stuck to his back. Job done, he buzzes off to the next intoxicating bloom where the package of pollen gets deposited onto the stigma of another bee orchid flower.
So far, so good – if you are a bee orchid in sunny southern Europe where they have been fooling the solitary long-horn bees they evolved with for millennia. Here in Ireland however, we have a relatively depauperate bee fauna and the right kind of bee does not occur. So Irish bee orchids make do with pollinating themselves, they are all dressed up with nowhere to go.
Orchids usually rely on fungal partners to enable their tiny seeds to germinate and grow
Not all orchids are as charismatic as the photogenic bee, fly, lizard, spider and lady's slipper kinds. A small unassuming Japanese orchid was thought to be quite rare and restricted until botanists found that it was commonly overlooked. This mukago-saishin orchid produces a flowering stem in late spring, before any leaves appear. Leaves only appear after the flower has set seed and they gain resources to feed back into the underground tuber which can then stay dormant through the dry season in its subtropical habitat.
Like many orchid species this delicate Japanese beauty occurs in a very resource limited environment and relies on fungal partners (mycorrhizae) to provide it with critical nutrients from the thin layer of decayed leaf litter where its tubers are found. Orchids usually rely on fungal partners to enable their tiny seeds to germinate and grow. At these initial stages the fungus has nothing to gain from the association, it is either being coerced into providing the orchid seed with a service or it is playing a long game, nurturing the developing orchid in the hopes that it will provide the fungus with carbohydrates once it is photosynthetic.
Orchid development can be a very long game indeed, while the Japanese mukago saishin might only live for one or a few years, others like theearly spider orchidcan live for up to two decades.
Orchids are one of the most species rich families of plants in the world and despite their sometimes very specialised pollination systems some have been found to thrive in human disturbed habitats and be able to persist through disruptions to their pollination systems. However, there are many species of orchids which are highly threatened by land use change, as fertilisation of grassland habitats damages their fungal partners, and they get outcompeted by stronger neighbours. Climate change is also playing havoc with the timing of pollination as insects and flowers emerge at different times.
Looking after our semi-natural orchid rich grasslands protects not just the pretty flowers, but all the partners they deceive, embrace and reward.
Yvonne Buckley is an ecologist, Irish Research Council laureate and professor of zoology at Trinity College Dublin