Fungi could help tackle some of the world’s big challenges, such as finding clean fuels and tackling plastic rubbish, experts have said.
A report by The Royal Botanic Gardens, Kew, has estimated that there are three million species of fungi but so little is known about them, they have been called the "Jekyll and Hyde" of nature.
Experts have also warned that many species could be threatened because of climate change which could harm wildlife and natural systems that rely on them.
Only 56 species have had their conservation status assessed for the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species, compared with 25,452 plants and 68,054 animals.
However, the first ever State of the World's Fungi report revealed that they are hugely important to life as fungi that grow around roots help plants absorb more water and nutrients so that around 90% of the world’s plants thrive.
Many are now looking to the fungi kingdom to help tackle environmental challenge as some have the potential to clean up radioactive waste and others might hold the key to making biofuels, the report said.
More than 2,000 new species of fungi were found last year, in the soil, forests and caves.
But new micro-species were also found in diverse places including under fingernails, on a baby carrier and on oil paintings.
Around 350 species are eaten by humans, from truffles to common mushrooms, meat substitutes and blue cheese, as well as products such as beer and bread which need yeast, in a market worth £32 billion a year.
Analysis of a packet of porcini mushrooms from the supermarket has even revealed three new species.
Experts have said that many fungi were undervalued as they were not easily visible, while habitats such as woodland and wetland edges where they are found are being lost.
Director of science at Kew, Professor Kathy Willis said the potential of fungi is "very strong" but more research was needed.
She said: “This is an incredibly diverse, yet hidden kingdom. Our knowledge of fungi is so small in comparison to plants and animals.
“And yet in terms of addressing global challenges going forward, fungi may well hold many of the answers.”
A fungus has been found in a rubbish tip in Pakistan which is capable of breaking down plastics such as polyester polyurethane in weeks rather than hundreds of years, raising hopes of new ways to tackle global plastic pollution.
One new species identified in the sandy desert soils of the United Arab Emirates (UAE) could be helping lime, pomegranate and grape plants survive the harsh conditions.
They also provide medicines, such as penicillin, statins and immunosuppressant drugs needed for transplants, and speed up chemical processes in industry.
But they can also be among some of the most dangerous organisms, responsible for problems such as ash dieback and honey fungus.
Climate change could harm beneficial species with knock-on effects for other plants.
Rising temperatures could also mean the spread of fungal pathogens but they could also help plants alleviate some of the effects of climate change such as drought and increased flooding, the report said.
Prof Willis said: “They are the Jekyll and Hyde, because they are important for all aspects of life on Earth but they are also some of the most devastating organisms to life on Earth.”
She added: “We need to change this because with climate change many fungi are getting very stressed, they like rain, they like damp, moist environments, as things get drier and hotter, things getting lost are those key fungi.”