By Christine Jeavans
Magic mushroom users have long benefited from a loophole in the law that meant fresh varieties of the hallucinogenic fungus were legal, despite dried ones being banned. But now the trip is over.
They have a reputation as the ultimate hippy dippy drug, beloved of Hawkwind fans and "psychonauts" probing the doors of perception.
Yet despite magic mushrooms' associations with a more innocent, bygone era, their popularity has soared in recent years. The rise has gone hand in hand with growing availability.
Instead of having to dodge cowpats to hunt native Liberty Caps in damp fields each autumn, users in Britain have had their pick of exotic species at "headshops", market stalls and internet retailers up and down the land.
Magic mushrooms in their fresh, raw state have not, until now, been illegal, even though preparing them has been.
But a change in the law meant Sunday was the last day of legal trading - prompting a last-minute rush to buy them in places such as Camden in London.
Retailers have opposed the ban on fresh mushrooms
"I'm buying them to share with friends at a barbeque tonight," says Tom, 23, from Australia as he pops the 50g bag of Mexican Cubensis, costing £20, into his backpack.
"It's a bit of a laugh. I guess I would have to go to the 'underworld' if I want to get any more after today."
Although very much a minority pursuit, mushrooms had been bucking the trend of many other drugs. LSD-use has fallen to a negligible level and ecstasy and cannabis use appears to be steady, according to latest government figures.
Anecdotal evidence suggests that while the fungi are still seen as a largely teenage thrill, they have begun to appeal to an older crowd.
"I was never one for mushrooms when I was younger but I bought them for the first time at last year's Glastonbury festival," says Terry, 35, from east London.
"By Sunday everyone around us looked off their heads and we wondered what all the fuss was about so we got some. I've bought them a couple of times since then."
Although the growing availability of magic mushrooms helps explain a rise in popularity, there are other reasons, says Dr Russell Newcombe, senior lecturer in drug use and addiction at Liverpool John Moores University.
"There has always been an underlying interest in alternative experiences and states of consciousness but that has risen a lot more in the past 10 years or so," he says.
MAGIC MUSHROOM FACTS
Trips last 4 - 8 hours, depending on quantity and type taken & user's state of mind
Can cause vomiting, anxiety and paranoia
Particularly risky for those with mental health problems
Users can expect intensified colours & lights, laughing fits, hallucinations and losing track of time
"It goes with that whole section of our youth culture today which is interested in getting experiences, travelling the world and doing risky sports.
"On the other side of the coin there is a need for mystical and spiritual experiences to offset people's secular lives."
The effects, and drawbacks such as paranoia, vary [see box above] but when a trip is particularly intense, users report a loss of ego or a renewed sense of their place in the universe.
"I lay on the ground and felt like I was hugging the world," said Mark, 30, from Bristol.
With effects like this it's unsurprising that magic mushrooms are linked to ancient religious ceremonies such as those of the Aztecs who called them Teonanacatl, God's flesh.
In the UK their history is a little more obscure although folklore gives clues that Britons have been well aware of the hallucinogenic properties of plants for centuries, including both the small brown Liberty Cap (Psilocybe semilanceata) and the red and white, and more toxic, Fly Agaric (Amanita muscaria).
Flying witches, powerful fairy rings and elves' predilection for sitting on red and white toadstools have all been ascribed to experiences with magic mushrooms.
Copelandia cyanenscens (Hawaiian)
Psilocybe mexicana aka Philosopher's stone
However the first documented case was in London's Green Park in 1799 when a man who had been picking mushrooms for breakfast accidentally sent his entire family on a trip.
The doctor who treated them later described in the Medical and Physical Journal how the youngest child "was attacked with fits of immoderate laughter, nor could the threats of his father or mother refrain him".
There are theories that Lewis Carroll knew what he was talking about when he had Alice eat pieces of mushroom, as advised by a hookah-smoking caterpillar, which made her grow and shrink.
But the psychedelic influences of the 1960s and 70s brought mushrooms to a wider audience, when they started to be used as a milder or more natural alternative to LSD.
The popularity increased following the publication of a guidebook to British mushrooms and a particularly high-profile 1978 court case in which the House of Lords decided fresh magic mushrooms were not illegal in their natural state.
That ruling has now been superseded with the Drugs Act 2005 which means they are now classified as a "Class A" drug, alongside heroin. Possession could lead to seven years in jail, while supplying them could result in a life sentence.
While the changes to the law will undoubtedly get rid of overt selling on the High Street, ardent mushroom fans may not be dissuaded.