Orchidelirium: The Sexual Prowess of Orchids

‘Orchid Sexual Deceit Provokes Ejaculation’, reads one headline as I dive headlong into the surprisingly well documented sex life of orchids. Orchids are amongst the largest families of flowering plants, with between 25-35,000 species found across all the continents except Antarctica. It must be said, they owe their successful continental conquest largely to their incredible sexual prowess, as well as their powers of seduction and deception.

Names, especially with plants, can act as clues, offering an insight into both botanical and cultural history. Orchids are no exception, with even their name, derived from the ancient Greek word for testicles ‘orkheos’,  indicating carnal associations.

I, like the Greeks, have always found orchids vaguely sexual, even cellophane-veiled in supermarkets they manage to maintain their strangeness, a quality undiluted by their drab surrounds.

I babysat one once, unknowingly mistaking it for a basket of weeds until it exploded in flower, chocolate-scented by the kitchen window. Its blooms were a shock, not to mention its perfume, which was completely worthy of its common namesake, the chocolate orchid.

Scent plays an important seductive role in orchids, and they are famed pseudo-copulators. With flowers often evolved to mimic the preferences and appearances of the female counterparts of their desired pollinators, many orchids dupe their unsuspecting lovers with counterfeit pheromones.  Wasps play an important role in this relationship – attracted to the flowers by a floral sex perfume (allomone), they attempt to mate with their mistaken partner, picking up pollinia or depositing it from another flower in the process.

Of course there’s no accounting for taste, with a particularly smutty native species, Spilorchis weinthalii , famed for secreting a semen-like scent that attracts blowflies with suspicious tastes in perfume.

In some cases an orchid’s preferred sex partner can be anticipated in the visual expression of its flower, with flowers visited by bees and wasps usually the most brightly coloured and fragrant, whereas white, cream or green flowers are notorious indicators of a moth-fetish.

Photo by Alex Crowe

Not all Australian orchids are so vulgar in their attempts to entice a pollen partner, and some are downright romantic;  Dendrobium teretifolium, with its drooping stems reaching up to four metres long,  attracts scarlet honeyeaters with its perfumed blossoms. The birds drink nectar from the plant’s white flowers whilst gently swinging from the heights of the rainforest canopy. Swoon!

I’m aware it can be mildly embarrassing to speak like this, anthropomorphising plants, but, not being a scientist, I can’t help but enjoy the human parallels in the sometimes bizarre, deceptive dance orchids make with their hapless insect lovers, and their use of perfume and mimicry to lure and inspire lust.

Maybe the fascination with this process lies in the reversal of expectations, in the notion that the perceived static, passive plant outplays the insect, the brainless enjoying an animated role we don’t expect.

Who would assume the wingless half of this relationship to appear the wiser?

It could be argued orchids have even worked their powers on us. The Victorians had a name for the condition of men (and they usually were men) who contracted orchid-collecting related fever; ‘Orchidelerium’, and, with 100,000 plus registered hybrids of orchids existing today, many of which wouldn’t exist without smitten human pollinators, maybe they were onto something.

Photo by Alex Crowe