Fungi and Mushrooms

Not a plant, not an animal

You might think a mushroom is a strange little plant. But it is not a plant at all! Fungi (say "FUN-guy" or "FUN-jye") are their very own group of living things, separate from plants and animals. A single one is called a fungus. Mushrooms, mould, mildew and yeast are all fungi.

Why are they not plants? Plants are green and make their own food from sunlight, using photosynthesis. Fungi cannot do that. They have no green colour and no leaves. Instead, fungi feed by soaking up food from things around them, a bit more like how an animal needs to eat.

The hidden part 🕸️

Here is a surprise. The mushroom you spot on the grass is only a small part of the fungus. It is the fruit — the part made to spread the fungus. The rest of the fungus is hidden underground or inside rotting wood. It is a huge web of fine white threads called mycelium.

These threads can spread far and wide. In fact, one fungus in a forest in America is so big that its underground threads stretch for kilometres, making it one of the largest living things on Earth!

Spreading by spores 🍄

Plants make seeds, but fungi make spores. Spores are tiny — far too small to see one on its own. A single mushroom can make millions of them. Look under a mushroom's cap and you will see thin flaps called gills. Spores form there and drop out, and the wind carries them away. If a spore lands somewhere damp with food, it can grow into a brand new fungus.

Nature's recyclers ♻️

Fungi have one of the most important jobs in nature: they are decomposers. When a leaf falls, a tree dies or an animal dies, fungi go to work. Their threads spread through the dead material and break it down. This returns goodness, called nutrients, back to the soil, ready for new plants to use.

Without fungi, dead leaves and wood would pile up forever and the forest would run out of food in the soil. Fungi clean up and recycle, keeping the whole woodland healthy. They are real-life nature heroes.

Fungi that help us 🍞

We use fungi every day. Yeast is a tiny fungus that makes bread rise and go puffy — without it, bread would be flat and hard. As yeast feeds on the sugar in dough, it gives off a gas that fills the dough with tiny bubbles. Many cheeses, like blue cheese, are made with fungi too. Mushrooms themselves are a tasty food, used in soups, pizzas and stir-fries all over the world.

And one of the most important medicines ever discovered, penicillin, came from a mould. A scientist named Alexander Fleming noticed that a mould growing by accident in his dish was killing the germs around it. That mould became a medicine that fights germs and has saved millions of lives. So fungi do not just recycle the forest — they help feed us and heal us too.

Fungi and trees, working together 🌲

Here is one more amazing fact. Under the ground, the threads of many fungi wrap around the roots of trees and work together with them. The fungus helps the tree drink up water and minerals from the soil, and in return the tree shares some of the sugary food it makes. Both living things win. Whole forests are connected by these hidden fungus threads, almost like an underground network passing food and signals between trees.

A safe spore activity

You can capture fungus spores safely with a shop-bought mushroom and a grown-up's help. Take a fresh mushroom and gently pull off the stalk. Place the cap, gills facing down, on a sheet of paper. Cover it with a bowl so no draught can disturb it, and leave it overnight. In the morning, lift the cap and you will see a beautiful pattern of spores printed on the paper, called a spore print. It shows you exactly how the mushroom spreads. (Remember: never touch wild mushrooms outside, and always wash your hands afterwards.)

To compare fungi with green plants that make their own food, read Photosynthesis Explained. And to see how fungi fit into nature as decomposers, visit Food Chains and Ecosystems.