From 'zombie spiders' to Darwin's HMS Beagle collections: The top 10 fungi in Kew's incredible Fungarium

What do a golf ball, a parasitised tarantula and Charles Darwin have in common? They are all linked to a variety of fungal specimens scientists at the Royal Botanic Gardens, Kew have archived or imaged as part of Kew's ambitious Digitisation Project, which will formally come to an end early next year.

Kew's Fungarium, which sits hidden underground in a corner of Kew Gardens in west London, is home to one of the world's biggest and most important collections of fungal diversity. It holds more than 1.1 million individual specimens collected over the past 175 years and is a vital source of knowledge supporting Kew's scientific and conservation work, while also supporting visiting researchers from the sciences, arts and humanities.

Lee Davies, Fungarium Collections Manager at RBG Kew, says, 'There is honestly nothing quite like Kew's Fungarium anywhere else in the world and it is genuinely exciting to see these collections become more accessible outside of our corner of Kew, not only as specimen images and data, but also the molecular data which is locked away in the specimens. This really does maximise the potential of our collection in a way fitting for the 21st century.'

In 2024, Kew's scientists began another major project in the Fungarium and have been tapping into the genetic information stored within its 50,000 type specimens—these are the definitive reference specimens attached to scientific names. The Fungarium Sequencing Project looks to sequence about 7,000 of these fungi, making the data open source and publicly available online over the coming years, unlocking in the process new compounds and genetic secrets that could accelerate the discovery of new useful chemicals and medicines.

Dr. Ester Gaya, Senior Research Leader in Comparative Fungal Biology, says, 'It is incredibly exciting to imagine what diversity of compounds is hidden away in these collections. By sequencing these specimens, we hope to tap into these potential benefits, while providing new tools to accelerate species identification and insights into how fungi relate to one another through time.'

With an estimated 2.5 million fungal species out there, of which less than 166,000 have been described so far, resources like the Fungarium are an increasingly important tool in the ongoing fight against the dual crises of climate change and biodiversity loss.

Shaheenara Chowdhury, Digitisation Fungarium Operations Manager, adds, 'Fungi have been overlooked by the scientific community for so long, and yet they are amongst the most wonderful and mysterious organisms on the planet. To help spread this wonder, we have digitised the Fungarium's collections, granting both researchers and the public unprecedented access to the secrets hidden within. It's incredibly exciting to imagine what new discoveries are going to be made with the aid of this new, powerful resource.'

To help celebrate the Fungarium and its dedicated team of staff, here are the top 10 fungi found in Kew's collections—from some of the rarest to some of the spookiest mushrooms found on Earth.

The top 10 fungi in Kew's incredible Fungarium

1. David Attenborough's 'zombie fungus'—Gibellula attenboroughii

Just in time for the second series of HBO's hit series The Last of Us, this creepy species of parasitic fungus from Northern Ireland bears Sir David Attenborough's name and was only recently described as new to science. It was first spotted on the ceiling of a disused gunpowder store on an episode of the BBC's Winterwatch in 2021, before being thoroughly examined by an international team of scientists.

The fungus belongs to a group of so-called 'zombie fungi' that infect their invertebrate hosts and take control before killing them as part of their spore-spreading mechanisms. In this case, the hapless victim was an orb-weaving cave spider (Metellina merianae), though the fungus has also been observed to infect the European cave spider (Meta menardi).

With its mind-altering properties straight out of a horror film, G. attenboroughii is just one of many parasitic fungi represented in Kew's extensive collections.

2. Fungus collected during the first Everest expedition—Stereum hirsutum

Fungi exist in virtually every corner of the planet, and that does not exclude some of its most extreme environments. This is evidenced by a green box tucked away in a corner of the Fungarium containing a specimen of Stereum hirsutum with an incredibly exciting label: 'Stereum hirsutum, c. 15,000 ft, Nepal Himalaya, Everest Expedition 1953.'

Where exactly this specimen came from remains a mystery, as no other information about its collector has been logged. However, there was only one major successful expedition up the world's tallest mountain in 1953, and that was the expedition during which Sir Edmund Hillary and Tenzing Norgay scaled Everest's peak.

It is entirely possible this fungus was collected during this historic adventure or during one of the exploratory climbs made earlier that year. Regardless, it proves that fungi can thrive in extreme conditions and very remote ecosystems.

3. What a fun-guy!—Golfballia ambusta

Little is known about this species' exact origins other than that the first specimen arrived at Kew in 1952 from Lancashire. At first glance it strongly resembled some sort of puff ball-like fungus but upon further examination it was revealed to be a... burnt golf ball.

And yet, when another specimen arrived through Kew's letterbox some years later, the Head of Mycology at the time, Dr. R.W.G Dennis, decided to pull a prank on the wider scientific community. Although his exact reasoning is unknown, he officially described the damaged sporting equipment as a new species in Journal of the Kew Guild.

And so, in 1962, in a paper titled 'A Remarkable New Genus of Phalloids in Lancashire and East Africa', the 'fungal' species Golfballia ambusta was revealed to the world. Described as 'small, hard but elastic, spheres enjoyed by the Caledonians in certain tribal rites', its scientific name quite literally translates to burnt golf ball.

4. 'Beverly' the tarantula-loving parasite—Cordyceps caloceroides

Beverly the tarantula embodies some of the most terrifying examples of what parasitic fungi are capable of. Endearingly dubbed 'Bev' by the Fungarium's team of curators, this pale husk in the shape of a tarantula spider is in fact, the dried out remains of the fungus Cordyceps caloceroides.

Cordyceps is a genus of over 250 fungi known to infect insects and other invertebrates. These fungi spread their spores to infect helpless invertebrates, replacing their host's tissues with fungal mycelium and sprouting large, external fruiting bodies to release even more spores and continue the infectious cycle. Many can also cause changes in the host's behaviour to maximise the odds of successfully infecting other organisms.

But it's not all horror: scientists around the globe are investigating how these fungi could be useful for humans, such as researchers in China studying their potential as a natural insecticide against malaria-carrying mosquitoes. A compound produced by a related fungus in the same order as Cordyceps has also led to development of the life-saving drug ciclosporine, which helps prevent the immune system rejecting a transplanted organ.

5. A fungus collected by Charles Darwin—Cyttaria darwinii

Amongst Kew's numerous collections linked to the naturalist Charles Darwin, is a particular species of fungus he personally collected in the Tierra del Fuego archipelago in South America during the historic HMS Beagle voyage (1831-1836). Described by Darwin as ranging in size 'from a bullet to a small apple' and having the 'colour of a yolk of an egg' this small globular fungus is parasitic and grows exclusively on southern beech trees (Nothofagus).

Samples of the fungus were brought back to England, where one of Britain's first mycologists, Rev. Miles Joseph Berkely, gave the species its official scientific description and named it in honour of Darwin, Cyttaria darwinii.

Kew's Darwin collections span a wide range of items and specimens, including letters from the Beagle voyage and correspondences with his dear friend and Kew director, Sir Joseph Dalton Hooker. The archive collections have recently been inscribed into the UNESCO Memory of the World Register, alongside five other institutions.

6. On the oak—Lobaria pulmonaria

This large, green species of epiphytic lichen is becoming increasingly rare in the British landscape. Typically found growing on the bark of oak trees, as well as beech, maple and even rocks, Lobaria pulmonaria, like all lichens, is the product of a symbiotic relationship between a fungus and one or more algae and/or cyanobacteria.

It is incredibly sensitive to air pollution, acidic rain and the clearing of its habitat, meaning its range across the UK is decreasing. It can still be found on trees and rocks in western Scotland, west Wales, as well as parts of southern England, particularly in old forest and parklands.

L. pulmonaria is one of the more than 2,300 organisms that rely on oak trees—a fact highlighted in this year's Of The Oak exhibition at Kew Gardens. This immersive, one-of-a-kind installation from the art collective Marshmallow Laser Feast uses real-world data and cutting-edge technology to bring to life the seen and unseen rhythms of the famous Lucombe oak at Kew Gardens.

7. Shitake mushroom collected during the Challenger Expedition—Lentinula edodes

Despite being one of Japan's best known culinary ingredients, the shiitake mushroom (Lentinula edodes) boasts a lesser-known connection to the history of British mycology. The original type specimen of this species was collected during the famous Challenger Expedition (1872-1876) before being studied at Kew.

The collected specimen was described by Miles Joseph Berkeley and has been used by scientists in the Fungarium Sequencing Project to unlock secrets locked away in its genome.

L. edodes has been in cultivation for thousands of years, renowned for its nutritional value as well as some medicinal properties. It can be typically found growing on oak, poplar, maple and birch trees, while, in cultivation, sawdust and wood chip provide it with the perfect environment to thrive

8. A whole latte trouble—Hemileia vastatrix

Besides the increasing threats posed by our warming climate, coffee plantations around the world are also under threat from a fungal disease known as coffee rust. Caused by the fungus Hemileia vastatrix, coffee rust is among the most devastating pathogens known to affect plants in the coffee genus Coffea.

First discovered in Africa in 1861, it has quickly spread across the world's coffee-producing regions. In fact, its arrival in Ceylon (modern-day Sri Lanka) by 1867 has led to the island's coffee industry collapsing, paving way for tea plantations to take over.

Unlike many other fungal pathogens, rust fungi depend on a plant host to reproduce and thrive under high humidity. Kew's collections include a specimen of H. vastatrix collected in 1869.

9. Insect-infecting fungus—Ophiocordyceps nutans

Another incredible member of this terrifying group is the species Ophiocordyceps nutans, a parasitic fungus found growing on a Hemipteran shieldbug.

As in the case of 'Beverly', the fungus infects its host organism and effectively hijacks its body as part of its reproductive cycle. After eating the insect from the inside, it produces impressive external fruiting bodies that allow the fungus to spread its spores.

Because of its appetite for certain insects, O. nutans has been proposed as a natural insecticide against stinkbugs, which are known to cause significant damage to certain agricultural crops.

10. Alexander Fleming's mouldy medicine—Penicillium rubens

From treating strep throat to ear infections, the applications of penicillin are many, and it has been a staple antibacterial treatment for close to a century now. But did you know that this drug, or rather family of drugs known as penicillins, is derived from a group of mouldy fungi?

The origins of the drug trace back to 1929 when Scottish physician Alexander Fleming returned to St. Mary's Hospital in London from a holiday to notice that a petri dish with Staphylococcus aureus was contaminated by a mould that killed bacteria around it. Rather than dispose the dish, he studied it and found that the mould, now named Penicillium rubens, produced the potent antibiotic compound—penicillin.

This groundbreaking discovery, which was corroborated by other scientists in the following years, led to the development of an incredibly important class of antibacterial drugs and a Nobel Prize for Medicine in 1945.

Incredibly, many of those Penicillium fungi Sir Alexander worked on are now safely stored amongst Kew's Fungarium collections.

Provided by Royal Botanic Gardens, Kew