MUSHROOM MYCELIUM AND SPORES

Forest Junkie
Oct 29
6 min read

Where: All over Sweden

When: Best from late summer to early autumn

What: Mushrooms mycelium and spores

Autumn is an exciting time to take a hike in the forest. Mushrooms in all kinds of shapes and colours pop up out of nowhere — the forest floor suddenly feels alive, full of small wonders waiting to be discovered. But what we see above the ground is just the fruit — a small, visible part of a much bigger and older organism that lives hidden in the soil. Let’s take a closer look at mycelium and spores.

SPORES ARE TINY TRAVELERS

Every mushroom starts with a spore. Spores are like seeds, but much smaller — invisible to the naked eye. They don’t carry food reserves like plant seeds do, so they depend completely on landing in the right place: somewhere damp, dark, and rich in organic matter.

Once a spore finds such a perfect spot, it wakes up and begins to grow. It sends out fine white threads called hyphae, which spread through the soil or wood and together form the mycelium — the true body of the fungus.

HOW MUSHROOMS RELEASE THEIR SPORES

There’s not just one way for mushrooms to spread their spores. Fungi have developed many clever and sometimes surprising strategies to send their tiny travellers into the world.

Most use the air:

Gilled mushrooms, like the fly agaric or common field mushroom, have thin plates under the cap. Between those gills, the spores grow and drop down when they’re mature, carried away by air currents.
Pored mushrooms, such as boletes, have a sponge-like underside full of small tubes. Spores form inside these tubes and fall out through the pores.
Veined mushrooms, like the chanterelle, don’t have real gills but soft folds that look similar. The spores grow along those folds and are released gently over time.
Spiny mushrooms, like the hedgehog mushroom (Hydnum repandum), have tiny downward-pointing spikes (or teeth) instead of gills. Spores grow on the tips and fall off when touched or moved by air.

Puffballs release a visible cloud of spores

But nature loves exceptions — and some mushrooms have developed truly unusual methods:

Ink caps are masters of transformation. When their spores are ripe, the whole cap slowly dissolves into a dark, inky liquid. That “ink” drips to the ground, carrying spores that can be washed away by rain or picked up by insects.
Puffballs and earthstars take a more playful approach. When touched by a raindrop, a falling leaf, or a curious hiker, they release a visible cloud of spores, like a small puff of smoke. In some earthstar species, the outer layer opens up like a star when it’s humid and closes again when it’s dry — perfectly tuned to the weather.
Stinkhorns (Phallus impudicus, called stinksvamp in Swedish) use a completely different strategy. Their spores sit in a sticky, smelly slime that attracts flies. The insects feed on the slime, pick up spores on their legs, and spread them further through the forest — much like bees spreading pollen.
Bird’s nest fungi (Crucibulum, Cyathus) look like tiny nests filled with eggs. Each “egg” is a capsule full of spores. When a raindrop hits the nest, the capsule shoots out — sometimes up to a metre away! It’s one of the most charming examples of how fungi use the power of water to spread life.
Truffle-like fungi (Elaphomyces) hide underground and depend on animals such as mice, squirrels, and wild boar to dig them up. The animals eat them, and the spores pass safely through their digestive systems to start new fungal colonies elsewhere.
And even the humble slime moulds — not true mushrooms, but often found in Swedish forests — have their own way. Their fruiting bodies dry into a powdery mass that releases spores through the wind or by the footsteps of insects. Some even shimmer in bright colours, like tiny metallic sculptures hidden on a piece of wood.

Ink Caps — Ink caps slowly dissolves into a dark, inky liquid

Each of these methods tells its own story about adaptation and survival. From raindrops and flies to curious forest creatures, fungi have found countless ways to ensure that their spores — and their species — keep travelling through the endless cycle of the forest.

THE ART OF MAKING A SPORE PRINT

If you want to see what mushroom spores look like, you can make a spore print yourself. Simply remove the stem of a mature mushroom and place the cap, gills down, on a piece of paper. Cover it with a bowl and leave it for a few hours or overnight. When you lift the cap, you’ll see a delicate pattern — a perfect natural print made by thousands of fallen spores.

Each species has its own spore colour, from pure white to creamy yellow, brown, pink, or even dark purple. For mushroom enthusiasts, this is an important identification clue. It’s also a fun and beautiful way to observe fungi more closely — and a great photo subject, too!

MYCELIUM – THE HIDDEN NETWORK BENEATH OUR FEET

What we call a mushroom is just the fruiting body, the visible part that appears when the fungus wants to reproduce. The real organism lives underground as mycelium — a vast, branching network of fine threads that spread through soil, wood, or leaf litter.

If you’ve ever seen a patch of forest where wild boar have been digging, you might have noticed thin white or yellowish threads in the turned-up soil. That’s the mycelium — usually hidden, but visible for a short while when the ground is freshly disturbed. It’s the living web that connects and nourishes the forest.

Mycelium plays a crucial role in the forest:

It recycles organic material, breaking down fallen leaves, wood, and needles into nutrients.
It forms partnerships with trees and plants through their roots, helping them absorb water and minerals.
It even connects trees underground in what scientists call the “wood wide web”, allowing them to share nutrients and warning signals.

Without fungi, the forest would quickly be buried under dead plant matter — and many plants wouldn’t survive without their fungal partners.

WHY SPORES ARE STILL IMPORTANT

You might wonder — if mushrooms grow out of the mycelium, why do they need spores at all?

It’s true: the mushroom is the fruit of an existing mycelium. But the spores are how the fungus spreads and starts new colonies elsewhere. A single mycelium can only grow so far before the soil around it runs out of nutrients or becomes too dry. When that happens, the fungus needs a way to move on — and that’s where spores come in.

Each spore is like a tiny traveller, searching for a new home. If it lands in the right place — damp, shady, and full of organic matter — it can germinate and grow into a new mycelium of its own. Most spores won’t make it that far, but mushrooms produce them in incredible numbers: millions, even billions, in just one season.

Most spores fall close to their parent mushroom, but wind, rain, and even insects can carry them many metres or even kilometres away. And while the forest floor may already be full of fungal life, there’s always a chance that one of those spores finds an empty patch and begins a new cycle underground.

It’s a bit like a fern in the forest: the green plant grows from its roots year after year, but it relies on spores to reach new ground and start fresh life somewhere else.

DO MUSHROOMS ALWAYS GROW BACK AT THE SAME PLACE?

Often they do, but not because the same mushroom returns. The mushroom itself is short-lived — it appears only when conditions are right: enough moisture, the right temperature, and plenty of energy stored in the mycelium.

As long as the underground network stays healthy, new mushrooms can appear year after year in the same spot. Some mycelium networks have been found to live for hundreds of years!

After heavy autumn rain, you might see mushrooms pop up within a few days — as if the forest suddenly decided to decorate itself. And when the air turns cold, they disappear again, leaving only the hidden mycelium waiting patiently for another season.

A QUIET KIND OF MAGIC

The world of fungi is full of quiet miracles. Every puff of spores, every melting ink cap, every tiny spiny mushroom is part of a vast and ancient cycle that keeps the forest alive.