Mushrooms: The One That Heals and The One That Kills
Coming home from a hunting trip in the Hungarian border, Charles VI, the Holy Roman Emperor, had taken ill. Nine days later, he died, thus ending the five-hundred-year-old line of male succession in the dynasty. In his memoir, Voltaire writes that the Emperor’s death was caused by eating a pot of death cap mushrooms; a poisonous mushroom known to have a fatal effect on the kidneys and liver. It was “the pot of mushrooms that changed the course of history,” says Voltaire.
While one mushroom killed an emperor, another is associated with immortality. Mushrooms have the “ability to play both Dr. Jekyll and Mr. Hyde roles”, says Professor Kathy Willis, director of science at Royal Botanic Gardens, Kew. Owing to its checkered past as well as its reputation as an elixir, it isn’t surprising that the use of mushroom has befuddled many.
In China, another mushroom, Lingzhi （灵芝）, is often referred to as the “Mushroom of Immortality; the elixir of life” in Hanshu （汉书）. Till today, Lingzhi is still used for medicinal purposes. Although bitter in taste, it is believed to have the ability to lower blood pressure, prevent hypertension and help in cancer management.
Mushrooms are subsets of fungus. “Fungus in the scientific sense, means any group of simple plants which include mushrooms,” says Alan Davidson in Oxford Companion to Food. The diversity of fungus makes it difficult to name the total number of species in the world. According to Royal Botanic Gardens, Kew, the latest best estimate would be somewhere between 2.2 and 3.8 million fungal species and at least 350 species are consumed as food. However, most of the wild mushrooms cannot be cultivated due to their dependency on other living plants to grow. Like all fungus, mushrooms “grow as parasites on crops,” says Davidson. Mushrooms that could be cultivated, such as the button mushroom, feed on dead organic matter, which makes it easier to grow them in large quantities.
The Chinese claim to be the first to have successfully cultivated one of the most popular mushrooms, Jew’s ear or wood ear （木耳）, also known as Auricularia auricula-judae, since 600 AD. One of the first mushrooms to be cultivated out of China was the button mushroom, also known as Agaricus bisporus, in 1650 AD, in France. Today 40% of mushrooms cultivated in the world are button mushrooms and it is one of the most widely consumed mushrooms. It is also known to have medicinal values.
But what do we look for in a mushroom to differentiate the one which heals and the one which kills? What should you look out for if you are picking mushrooms in the wild?
Wild Food UK debunks three myths when it comes to mushrooms foraging.
- ‘It’s ok if you can peel the cap.’ It is easy to peel a Death Cap.
- ‘Mushrooms growing on wood are safe.’ No not all of them are and some are deadly, like the Funeral Bell.
- ‘If you see other animals eating them they are ok.’ This rule is not true, as many animals can eat poisonous fungi with no ill effects.
Steve Trudell and Joe Ammirati, authors of Mushrooms of The Pacific Northwest, advise “not to pick mushrooms from places where they could have become contaminated by garden chemicals, fallout from vehicle exhaust, or other pollution sources”.
Moreover, there are poisonous mushrooms that look like the edible ones. Tradd Cotter of Mushroom Mountain named two of such harmful mushrooms: the chanterelle which resembles jack-o-lanterns, and the false morels which do not have a distinct difference in appearance to the real morels.
Hence, when it comes to telling whether a mushroom is edible, as a rule of thumb, Cotter has only two words of advice, “don’t guess”.