Fly agaric again

This is fly agaric, a mycorrhizal fungus, Amanita muscaria, which is found in the reserve every year despite our lack of its preferred partners: birch and pine trees. In classic pictures of this red and white fungus, those that don’t have an elf sitting on top are usually growing picturesquely in the moss under a birch tree.

These are the fruiting bodies of a widespread underground mycelium that forms mutually beneficial associations with the trees around it: a partnership in which the tree provides the fungus with some of the benefits of photosynthesis and the fungus helps the tree access nutrients and moisture from the soil. Fruiting bodies carry the fungus’s spores to the surface where they can be dispersed to grow in new sites.

The white spots on the Amanita’s red cap are the remains of a veil that covered it, perhaps protected it, as it pushed through the soil. At the base of its stem, it is bulbous; it emerged from a capsule, the remains of which form a ragged ring, called an annulus, around the stem just under the cap.

Left: immature fruiting body still covered by the veil that will form the spots; right: the ring around the stem, called an annulus, remains of the capsule.

In the header picture, there is a large hole chewed in the edge of the cap by something with more substantial teeth than a slug. Mice and all kinds of mammals can eat fly agaric without being poisoned though we are not so sure that they escape its psychotropic effects.

Fly agaric is dangerous, causing serious gastric upset, psychosis and the occasional death. Its name comes from its use in the past as an insecticide: the cap broken up into milk both attracts and kills flies. The name A. muscaria comes from the name for the common house fly, Musca domestica.

As with all fungi, the rule is don’t mess with them unless you have the advice of an expert.