Fungi aren’t plants, they belong to their own kingdom and are actually more closely related to animals. In the UK, scientists have identified over 15,000 species, of which less than a third produce visible fruiting bodies such as mushrooms, puffballs, and bracket fungi.  

A single giant puffball (Calvatia gigantea) can release an astonishing seven trillion spores into the air. Yet the visible fruiting body is only the tip of the fungi. The real bulk of the fungus is hidden underground or in its food source: a network of fine threads called mycelium, which can grow through soil, wood, flour or even jet fuel. (The so-called kerosene fungus thrives in aircraft fuel tanks, so antifungal agents are added to stop it clogging engines!) 

Some fungi are adaptable generalists, while others are picky specialists. The splitgill fungus (Schizophyllum commune), for example, is a generalist as it grows on a huge variety of dead wood from broadleaf trees all over the world and is most widespread fungi on Earth. It also has over 28,000 different sexes, a reminder that fungi relationships are every bit as complicated as human ones. 

You can find fungi at any time of year, but the best seasons are spring and autumn, when warmth and dampness bring fruit bodies to life. Knowing where to look is half the fun. In the UK, the two main habitats are grassland and woodland.  

Identifying what a fungus is growing on can help narrow down possibilities. Though sometimes it’s hard to tell whether the mycelium is feeding on moss, a buried twig, or the surrounding soil. But with practice you’ll discover bird’s nest fungi (Nidulariaceae) often appear on woodchip, while wood ear fungi (Auricularia auricula-judae) grow mainly on elder trees. 

Sadly, fungi are disappearing from both urban areas and intensively managed farmland, where soils are often hostile to fungal life. However, fungi also appear in the most unexpected places. Desert truffles (Terfezia species) grow in sand, several fungi species have been found living on the outside of space stations, and a radiation-loving yeast (Cryptococcus neoformans) has been discovered thriving at Chernobyl. 

When it comes to identification, colour is rarely reliable, except perhaps when spotting the most well-known of toadstools the fly agaric (Amanita muscaria) or lesser known shaggy scalycap (Pholiota squarrosa), which glows bright green under ultraviolet light. For most fungi, shape is a better clue: from classic cap-and-stem mushrooms to stinkhorns, trumpets, cups, clubs, puffballs, and brackets. 

Texture and smell are also helpful. Is it slimy, waxy, scaly, or woody? Does it smell of radish, potato, bleach or perhaps coconut, honey, or ink? Some fungi are unmistakable once you catch their scent. 

Fungi are remarkable recyclers of the natural world, yet they’re also inspiring human innovation. The oyster mushroom (Pleurotus ostreatus) is now being used to grow sustainable packaging and insulation, while other fungi are showing promise in breaking down plastics. 

The best way to start your own fungi journey is out in nature. Join a Wildlife Trust fungus foray, walk or workshop and discover these hidden treasures for yourself. Visit our events page and search for fungi. 

If you’re interested in reading more about fungi, a great starting point is From Another Kingdom: The Amazing World of Fungi, edited by Lynne Boddy and Max Coleman.