Fly Agaric: The Fairy-Tale Toadstool of the Birchwoods

Each major claim carries one of three labels. established means supported by primary records, official bodies or several independent reliable sources. shared means the core fact is sound but sources disagree on details, dates or interpretation. traditional means widely repeated but not traceable to a primary or independent source.

The biology and toxicology of the fly agaric are well studied. Its cultural history attracts many popular theories that go well beyond the evidence; this card labels those.

Not a plant

established The fly agaric is a fungus. What we see above ground is only its fruiting body, which produces spores. The main organism is a network of fine threads, the mycelium, spread through the soil. Like many woodland fungi, it is mycorrhizal: its threads wrap around the fine roots of trees, especially birch and pine, supplying them with water and minerals in exchange for sugars. In Scotland it is common wherever these trees grow, in native pinewoods and birchwoods, plantations and parks.

What it looks like

established The cap, typically 8 to 20 centimetres across, is bright red or orange and dotted with white warts, the remains of a veil that covered the young mushroom. The gills and stem are white, the stem has a skirt-like ring and a swollen base with rings of warts. Rain can wash the warts off and fade the cap to orange. It fruits from late summer into autumn.

Poisonous, but rarely deadly

established The fly agaric contains ibotenic acid and muscimol, which act on the brain to cause nausea, drowsiness, confusion, agitation and hallucinations. Poisoning is unpleasant and occasionally serious, but deaths are rare. It belongs to the same genus as some of the deadliest mushrooms in the world, including the death cap and destroying angel, which is one reason why no wild mushroom should ever be eaten without expert identification.

The fly-killer

shared Its common name, and the species name muscaria (from Latin musca, "fly"), come from an old European practice of breaking the mushroom into a saucer of milk to attract and stupefy flies. Experiments have shown that the mushroom does contain compounds that affect flies, giving the practice some basis.

Shamans, Vikings and Santa

established European travellers from the eighteenth century onward recorded that peoples in Siberia, such as the Koryak, used fly agaric as an intoxicant, sometimes drinking the urine of those who had eaten it to recycle the active compounds.

traditional Many further theories are popular but speculative: that Viking berserkers ate fly agaric before battle; that it was the sacred "soma" of ancient Indian texts; or that the red-and-white Santa Claus, flying reindeer and gifts under the tree derive from Siberian shamanic use of the mushroom. These ideas circulate widely but lack solid evidence.

A fairy-tale image

established Since the nineteenth century the fly agaric has been the standard toadstool of fairy-tale illustration, Christmas decorations and children's books, from garden gnomes to video games. In Scotland it is one of the most photographed fungi of autumn.

• The fly agaric is a fungus, not a plant.
• It lives in partnership with the roots of birch and pine.
• Its white spots are remnants of a veil that covered the young mushroom.
• It was once used to kill flies, hence its name.
• It is poisonous but rarely fatal.

• Myth: The fly agaric is a plant. It is a fungus. The mushroom is only the fruiting body of a network of threads, the mycelium, in the soil.
• Myth: The fly agaric is deadly. It is poisonous and can cause nausea, confusion and hallucinations, but deaths are rare. Its relatives the death cap and destroying angel are among the deadliest mushrooms in the world.
• Disputed: That it inspired Santa Claus, Viking berserkers or the sacred "soma". Use as an intoxicant by peoples in Siberia, such as the Koryak, is documented. These further theories circulate widely but lack solid evidence.
• Disputed: The fly-killing origin of its name. The practice of breaking the mushroom into milk to stupefy flies is old, and experiments show it contains compounds that affect flies, but the story is only partly supported.