A place on your table?

The combination of warmth and rain over recent weeks has triggered a mass of fungal fruiting bodies to emerge across the countryside. Fairy rings of mushrooms dot many of the grassland swards around here and little groups of toadstalls adorn decaying stumps or cluster around the root balls of still living trees. Some of these fruiting bodies would make a tasty meal but knowing which requires a degree of skill and understanding. Over the years I have sampled a number of different fungi; from the meaty textured Cep through to the delicate flesh of the Parasol Mushroom and the butter-greedy Giant Puff-ball. However, my real interest remains in the natural history of these organisms rather than in their culinary value.

In particular, I have always been interested as to why some species are highly poisonous while others (even closely related ones) remain entirely edible (and rather tasty). For example, one of our most dangerous species, the Death Cap, contains a cocktail of poisons that not only interferes with some of our body’s most fundamental processes but also actively targets cell nuclei in the liver and kidneys. Death comes after a week and the species is responsible for 93% of all fungi-related poisonings in Europe; yet despite this, slugs, maggots and Rabbits all seemingly eat this toadstall with impunity. Is it a chance of chemistry that has made the Death Cap so deadly to us?

The Death Cap belongs to a wider group of fungi known as the Amanita and this group (of which we have roughly 30 species) contains toadstalls with some wonderful names. Along with the familiar Fly Agaric, there are the Panther, the Blusher, the Destroying Angel and the aptly-named Fool’s Mushroom. While some Amanita are edible (for example, Caesar’s Mushroom – which has been prized since Roman times) most are inedible and a few are deadly. Several species are considered edible after thorough cooking. The toxins of the Blusher, which attack red blood cells and cause a form of anaemia, are broken down by parboiling. The same is true of the toxins contained in the Grisette and Tawny Grisette, two species that were formally thought of as being edible without the need for cooking! The Amanita are fairly easy to identify as a distinct group because they share a number of common features that can be seen in the field. Separation of certain species within the group is, however, less easy. This is another reason why the comments made by one famous mycologist in describing these toadstalls are best followed. He noted that this is a group of fungi ‘to which it is better to devote a purely botanical interest than to give them a place on your table.’