10 fun facts about fungi

RHS Plant Pathologist Ruth Chitty shares some fascinating facts that reveal just how extraordinary fungi are. From their role in ecosystems to their surprising connections with humans, fungi are far more remarkable than many people realize.

The World’s Largest Organism Is a Fungus

One of the largest living organisms on Earth, measured by area, is a type of fungus. A honey fungus species (Armillaria ostoyae) discovered in Oregon in 1998 was estimated to spread across around 2,384 acres of forest. This enormous organism has existed for more than 2,400 years, surviving by feeding on both living and decaying wood.

The mushrooms we see above ground are only a small visible part of the fungus. Most of the organism remains hidden beneath the soil as a vast network of tiny thread-like structures called hyphae, which together form the mycelium.

Fungi Help Keep the Planet Clean

Fungi play an essential role in breaking down organic material and maintaining healthy ecosystems. Without decomposer fungi, also known as saprotrophic fungi, the world would become covered with piles of fallen leaves, branches, and dead plant material.

These fungi produce special enzymes that allow them to break down difficult plant compounds, including cellulose, hemicellulose, and pectin found in plant cell walls. Certain wood-decaying fungi are even capable of breaking down lignin, one of the toughest components of wood.

Through decomposition, fungi help recycle important nutrients such as carbon and nitrogen back into the environment, supporting new plant growth. Researchers have also discovered more than 100 fungal species that can break down plastics, with some able to decompose plastic materials within only 140 days.

Fungi Are More Closely Related to Animals Than Plants

Although fungi are often grouped with plants because they grow in soil and produce mushroom-like structures, they actually belong to their own biological kingdom. Scientific studies have shown that fungi share a closer evolutionary relationship with animals than with plants.

One example is chitin, a material found in fungal cell walls. This same substance is also present in the outer shells of insects and other arthropods.

The Number of Fungi Species Is Still Unknown

Scientists have identified around 200,000 species of fungi worldwide, including approximately 15,000 species recorded in the United Kingdom. However, researchers believe this represents only a small portion of fungal diversity.

Current estimates suggest that there may be another two million fungal species waiting to be discovered.

Humans Have Used Fungi for Thousands of Years

People have been benefiting from fungi for more than 5,000 years. When the ancient frozen human known as Ötzi the Iceman was discovered, two different types of fungi were found among his belongings.

One of them, birch polypore (Fomitopsis betulina), may have been used as a natural medicine because of its possible laxative and antibacterial properties. Scientists believe Ötzi may have used it to treat intestinal parasites or as a protective covering for wounds.

Today, fungi continue to contribute to modern medicine. A famous example is penicillin, an antibiotic originally developed from a Penicillium mould.

Researchers are also studying how different fungi can benefit gardens. Scientists at the RHS are investigating whether saprotrophic fungi in soil can help protect plants from honey fungus infections.

Fungi Are Hidden in Everyday Household Products

Fungi are found in many places around our homes, not just in food storage areas. Enzymes created by fungi are used in the production of various everyday items.

For example, stonewashed jeans are made using fungal enzymes that soften cotton fibers. Another fungal product, itaconic acid, is used in creating certain plastics, including materials used for car parts and building blocks such as Lego.

Fungi Have Existed for Over a Billion Years

Fungi can be found in almost every type of environment, including forests, grasslands, deserts, sand dunes, and even glaciers.

Genetic research suggests that fungi first appeared on land around 1.3 billion years ago, although this timeline is still debated because fossil evidence from ancient fungi is extremely limited. If these estimates are correct, fungi arrived on land hundreds of millions of years before plants.

Fungi Create the Underground “Wood Wide Web”

Fungi form important partnerships with plants and trees through underground networks often called the “wood wide web.” Tiny fungal threads, known as hyphae, connect with plant roots and create a system for exchanging resources.

The fungi collect nutrients from the soil and trade them with plants in exchange for sugars produced through photosynthesis. This relationship benefits both organisms by improving growth and survival.

These underground networks may also allow plants and fungi to share information about environmental dangers, including insect attacks, drought conditions, and diseases.

Some Fungi Can Glow in the Dark

More than 110 species of fungi are known to produce natural light, a phenomenon called bioluminescence. In some species, only the underground mycelium glows, while in others the mushroom itself produces visible light.

In the UK, sulphur tuft mushrooms can be observed glowing under ultraviolet light. Scientists believe this glowing ability may help attract insects that assist in spreading fungal spores.

Some Fungi Are Surprisingly Powerful

Fungal fruiting bodies, such as mushrooms, can grow at remarkable speeds. Within just a few hours, they can absorb large amounts of water and expand rapidly.

This growth is powered by hydraulic pressure, allowing mushrooms to push through soil, wood, and other surfaces to reach open air and release their spores. In some cases, the pressure produced by fungi can become so strong that certain species can crack pavement or lift paving stones.

Exploring the World of Fungi

RHS Science continues to share knowledge about fungi through talks, demonstrations, and educational events at RHS Hilltop, the home of gardening science. These programs provide opportunities to discover more about the fascinating role fungi play in nature, gardens, and everyday life.