The British Isles are home to an astonishing 15,000 species of fungi. They can be found in almost every habitat, though they thrive particularly well in woodlands and grasslands.
How many species of fungi are there in the world?
It is estimated that there could be around 2.5 million species of fungi worldwide, but only a small fraction produce mushrooms, with about 14,000 formally identified and named.
Of these, just a few hundred to a few thousand are considered edible, while the vast majority remain unstudied or undiscovered. Many species are unedible, although just two per cent of the world’s fungi are truly deadly poisonous.
Have a read of the best mushroom identification books of 2025 – but, if in doubt, don't pick.
What are mushrooms?
Mushrooms are simply the fruiting bodies of fungi, representing a diverse yet still largely unexplored subgroup within this enormous kingdom.
What's the most common mushroom in the UK?
Several mushroom species are especially common across the UK, although rankings differ depending on the source.
The field mushroom (Agaricus campestris) is widespread in grasslands, while the oyster mushroom (Pleurotus ostreatus) can often be seen growing on trees throughout the year. Other familiar species include the common inkcap, the giant puffball, and the striking collared earthstar (Geastrum triplex), with its star-like rays spreading from a central spore sac.
Learn more about wild mushrooms and fungi:
