'Orchids are the closest you’ll get to sentient plants.' Picture: Wikimedia Commons

London - Mark Flowers is passionately, neurotically, radiantly obsessed with orchids. He has filled his Bristol home with them and built a temperature-controlled, artificial cloud forest, polytunnel in his back garden.

Orchid motifs are appliqued on his bedspread and embroidered on an armchair while an enormous "orchidarium" (a sort of aquarium for orchids which keeps them warm and humid) dominates his bedroom.

He chats to his orchids, worries about them, dreams about them and posts photos of their tangled, spidery roots online for fellow enthusiasts to enjoy.

It goes without saying, that Mark, 51, (an award-winning nature documentary maker) has an awful lot to say about the 20 000-plus species of orchids that grow everywhere on Earth except the North and South poles.

He tells me how unpredictable and diva-ish some are; how they "look" at us with their eyeless faces so orchid keepers feel they’re constantly being watched and  how clever they are at adapting to their environment.

"Orchids are the closest you’ll get to sentient plants - they have presence, characters, personalities and sometimes they sulk!" he says.

He also explains that, while many orchids are "very good and straightforward", others are "dishonest and naughty and dark".

For example, the bee orchid, Ophrys apifera, is so-named because it fools bees into attempting to have sex with it rather than going to the effort of producing its own nectar, as most other flowers do.

"It looks like, smells like and feels like a female virgin bee," says Mark.

Just before the key moment, the bee realises it’s being conned and buzzes off to try its luck elsewhere.

"Bees will only ever be fooled twice, but it’s enough to pollinate the next orchid," says Mark gleefully.

There has always been something a bit "other-worldly" about orchids. Perhaps it’s their long, snaking roots; their blank waxy faces, the flagrant sexiness of some species (the petals of many resemble women’s sexual organs) and the sauciness of some of the names (naked man orchid).

Even "orchid" comes from the Greek word "orkhis", meaning testicle, thanks to the paired tubers which look rather too much like male parts.

Myths about their powers have long been rife. The Ancient Greeks believed holding an orchid root could promote lust, and eating the larger, lower tuber promoted conception of sons.

For centuries they have driven botanists, explorers and collectors crazy with their elusive allure.

Now - largely thanks to breeding techniques developed in the Nineties - they are more popular than ever.

Mark, meanwhile, has loved orchids since he was 11, poring over his copy of Orchids For Everyone, which he still treasures.

"I wasn’t a sporty lad," he says. "My surname, Flowers, didn’t help, either!"