The fly agaric toadstool, on which fairies like to sit

Where can you find a panoply of poisonous, hallucinogenic, medicinal, pathogenic, or run-of-the-mill organisms from seven continents in one place?

Welcome to the “Fungarium”, more formally known as the mycology department of the Royal Botanic Gardens in Kew, London, which houses the world’s largest collection of dried fungi – an incredible 1.25 million specimens. It is also one of the world’s oldest collections, founded in 1879.

If you’ve ever wanted to get close to something that Charles Darwin collected during his voyage on HMS Beagle, this is your chance. Kew’s collection includes a “golfball” fungus that Darwin picked up in a market on the island of Tierra del Fuego, off the southernmost coast of South America, and preserved in what he had to hand – port. And you can take a look on Sunday 13 October.

The event is in honour of UK Fungus Day, a celebration of the humble, much overlooked, fungi. There are millions of species, but just 100,000 have been identified. Lucky visitors will have their very own mycologist to take them on a half-hour guided journey through this fungal fest.


Enter the Fungarium

Other iconic specimens housed in the two large underground rooms which make up the bulk of the Fungarium include a sample of the original strain of penicillin isolated by Alexander Fleming. And there’s a black, rather shrivelled mushroom picked up from a market in Japan during a late-19th century voyage by research ship HMS Challenger. This is the first shitake mushroom to be classified using formal taxonomy.

These “type specimens” are fundamentally important to taxonomy, and the Fungarium houses 50,000 of them. Not surprisingly, Kew’s mycologists are hot on the naming, classification and conservation of fungal diversity.

The two climate-controlled rooms – divided into “the world” and “Britain” – house many shelves stacked with 12,500 light, green boxes. Open the boxes, and layered in folders, fixed onto herbarium paper or sometimes in envelopes, are the specimens. On average, each box holds 100 specimens, but some contain a single, whole fungus.

The mycology department also offers free advice to hospitals on poisonings, and to members of the public who are worried about dangerous fungi they have spotted or accidentally eaten or touched.

Hundreds of hallucinogens

Kew holds several hundred specimens of hallucinogenic fungi such as the red and white fly agaric toadstool – which make the popular seats for fairies in children’s books. Fungi containing certain psychoactive chemicals that would be considered as scheduled drugs are kept off-site under lock and key, and even the department’s staff can’t access them without authorisation from the local constabulary.

“Fungi may be the most diverse group of eukaryotes in the world,” says Bryn Dentinger, head of mycology at Kew. But they are so woefully overlooked that it’s not unusual for unknown species to appear on our dining tables.

Every day in Britain, says Dentinger, people eat one or two species of porcini mushrooms unknown to science. These are usually imported from China’s Yunnan province.

The fungal kingdom includes yeasts, plant rusts, smuts, lichen and moulds as well as mushrooms. And there are fungal diseases. Takewhite nose syndrome, which is killing North America’s bats, or the chytrid fungus that is devastating amphibians.

For those who cannot make the tour, there is still plenty to enjoy with a fungi foray in the gardens on Sunday and some enchanting and gigantic willow sculptures of common UK mushrooms by Tom Hare, which line Kew’s Broad Walk. There are also pumpkin patches as part of the autumn phase of the IncrEdibles festival. And part of this celebration of plants we consume is the stunning new “pumpkin pyramid” in the Waterlily House.

With its towering mushroom fairy rings, and warmly colourful displays of many pumpkin species, Kew has evoked a fantastic autumnal twist to its popular festival.