Mushrooms and truffles: from the forest floor to the farm

The illustrations on this page are paintings, not identification guides. Many deadly mushrooms look like edible ones, and most mushroom poisonings follow a mistaken identification. The death cap, Amanita phalloides, causes the majority of fatal mushroom poisonings. Never eat a wild mushroom unless an expert has identified it in person.

Greek and Roman writers did not know what mushrooms and truffles were. Theophrastus described truffles as plants without root, stem, leaf or flower; Dioscorides thought they were tuberous roots; Plutarch said they formed where lightning, warmth and water acted on the soil, and Pliny the Elder also linked them with thunderstorms. Many of the truffles of the classical world were probably desert truffles of the genus Terfezia, milder than the European Tuber species.

Pliny, writing in the 70s CE, counted boleti among the foods people ate rashly. They were a rich dish, he wrote, but notorious since the empress Agrippina used them to poison the emperor Claudius, a crime by which, Pliny added, she gave the world another poison: her son Nero. He listed signs that supposedly marked poisonous kinds, and noted that fungi had recently killed a commander of Nero's watch, Annaeus Serenus, with several of his officers. He also recorded mushrooms threaded on rushes and dried, brought from Bithynia.

The death of Claudius, in October of the year Tacitus dates by the consuls Marcus Asinius and Manius Acilius (54 CE), is the most famous mushroom poisoning in history, but the evidence is thinner than the fame. Suetonius says the poisoning was "the general belief" but that when and by whom was disputed: some said his taster gave the poison, others that Agrippina served it in a dish of mushrooms. Tacitus says the poison was sprinkled on a fine mushroom. None of these writers says the mushroom itself was poisonous. The idea that it was a death cap is a modern guess.

The button mushroom, Agaricus bisporus, is the champignon de Paris. Its cultivation is believed to have begun in France around 1650, on beds of manure, and was refined over the following centuries. In the nineteenth century the crop went underground. According to the local history society of Nanterre, west of Paris, the "Paris" mushroom spread through the whole Paris region from the middle of the century, grown in old quarries that were dark, damp and a steady 10-12 °C, on ridged beds of manure covered with a specially prepared limestone soil. In Nanterre alone the prefecture licensed eight quarry mushroom farms between 1859 and 1869. The work underground was dangerous and unhealthy, and in 1909 mushroom workers in the Seine department struck for three weeks. Popular accounts give figures for how many cave growers there once were and say the building of the Métro drove them out of Paris; we have not found a scholarly or archival source for either, so they are left out.

In East Asia the great cultivated mushroom is shiitake, Lentinula edodes, a fungus that rots dead hardwood. A 2025 review by the Shanghai Academy of Agricultural Sciences describes three turning points: the traditional "shock" method on logs in China, pure-culture spawn developed in Japan, and the sawdust "synthetic log" developed in China. Early growers knew only that "gas" in the air and "cloud" in the log mattered, and that tissue from a mature mushroom could start a new crop; the "gas" and "cloud" were later understood as spores and mycelium. Western science came late: the English mycologist Berkeley named the species in 1877 from a poor specimen bought in a Japanese shop. China and Japan have taken turns as the largest producer. Since 2018 China has grown more than 10 million tonnes a year, over 95 % of the world's shiitake. The review gives no date for the first log cultivation, and this page does not offer one.

Truffles grow underground, so they have to be found by smell. In late medieval Italy the papal historian Bartolomeo Platina and the painter Ambrogio Lorenzetti both showed truffles being hunted with pigs and dogs. French hunters often used sows, which are drawn by a musky compound in black truffles similar to a boar's sex pheromone. Dogs are now preferred because they are easier to handle and do not eat the find. In Italy the Lagotto Romagnolo is the traditional breed, but almost any dog can be trained. Some hunters work without animals, watching for small yellow flies of the genus Suillia that hover over ground where ripe truffles lie.

Truffle cultivation began at the turn of the eighteenth and nineteenth centuries in France and Italy. The decisive step is credited to Joseph Talon, a farmer of Saint-Saturnin-lès-Apt in the Vaucluse, in Provence rather than the Périgord whose name the black truffle (Tuber melanosporum) carries. Talon noticed that truffles grew under certain oaks. He sowed acorns gathered from these natural truffle grounds, or by other accounts transplanted seedlings from under them, and after some years the young trees bore truffles. Most recent scholarly accounts date his first sowing to 1808; other accounts give dates up to about 1815.

Naturalists were only beginning to understand what a truffle was. In the first decade of the eighteenth century the botanist Joseph Pitton de Tournefort and the pharmacist Claude-Joseph Geoffroy made observations that helped show it was a fungus, but its tie to the tree remained a mystery. Talon's method was the basis of the black-truffle industry for more than 150 years, even though no one knew why it worked. It was also unreliable, because the transplanted seedlings often carried pests or competing fungi.

The explanation came in 1885, when the German botanist Albert Bernhard Frank, studying truffle roots, coined the word Mykorrhiza, "fungus-root", and argued that the fungus and the tree live in partnership. Many forest fungi, including truffles, chanterelles and ceps, trade nutrients with the roots of living trees. That is why they cannot simply be grown on a bed of manure like the button mushroom.

Applied science followed. From about 1969 to 1972 French and Italian researchers learned to inoculate young trees with truffle spores under controlled conditions. The first inoculated seedlings of T. melanosporum went on sale in 1973, and the first truffles from inoculated trees were gathered in 1978. Truffle orchards are now planted far beyond Europe. Yields from truffle orchards have fallen since the 1980s, for reasons researchers still debate: changes in rural land use, a changing climate, or both.