Devil's bolete (Boletus satanus)

SizeCap diameter: 8 - 25 mm

Classified as Rare in the UK.

The Devil's bolete (or boletus) appears as a large toadstool, usually around the base of beech and oak trees. It shares the characteristics of the bolete family in having a greatly swollen stem, and the whole toadstool looks as if it has been inflated like a badly-made dumpling. The cap is domed and rather bun-shaped. It is coloured a dirty chalky-white, and the stem is tinged with pink. The shape of this stem has been compared to a Chianti bottle. The underside of the cap has pores rather than the gills which most other fungi use to distribute their spores. The whole fungus smells of spice, but under no circumstances should it be tasted, as it is poisonous.

WARNING: many species of fungus are poisonous or contain chemicals that can cause sickness. Never pick and eat any species of fungus that you cannot positively recognise or are unsure about. Some species are deadly poisonous and can cause death within a few hours if swallowed.

This fungus is found mainly in southern Europe. Britain is in the northern-most limit of its range. In the UK it is rare, having been recorded from some 40 different places since 1970, but its appearances are usually unpredictable.

The Devil's bolete seems to prefer calcareous soils and is often found in association with beech or oak trees. Being a southern species it also likes warmth, and in the hot and muggy summer of 1997 it enjoyed a good season with more recorded than in many preceding years.

The visible part of any fungus, the mushroom or toadstool, is called the fruiting body, and is the means by which the fungus releases its spores. Except in tropical climates, the fungus itself cannot live in the open air, and it lives underground or within the body of another organism such as a tree or other plant. Fungi are not plants. They belong to a kingdom of their own and cannot manufacture their own food through photosynthesis. They spread by way of mycelia, fine root-like threads which are difficult to find and almost impossible to distinguish as individual species. These mycelia enable the fungus to obtain nourishment by dissolving the tissue of plants, living or dead. Some can even dissolve metal and plastic. Many fungi including the Boletaceae, grow around the roots of living plants including trees. This has the effect of extending the plant's root system over a wide area, enhancing the plant's uptake of water and minerals. The fungus benefits by absorbing organic compounds from around the plant's roots. These fungi are often essential for the plant's survival. The Devil's bolete appears in late summer and early autumn. It is a colourful species, which carries more than one surprise. If cut in half, the creamy flesh turns sky-blue. Its discoverer, an Austrian, claimed to be ill for days after he had first smelled it. This, together with its reputation for deadliness, convinced him that the fungus must have been the work of the devil himself.

Fungi, for reasons not fully understood, are unpredictable in their appearance. As they are only visible when they produce their fruiting bodies, it can be impossible to tell whether a fungus is widespread or rare. The Devil's bolete does not appear to be common in the UK, and surveys are continuing to establish its true status.

The Devil's bolete is a priority species under the UK Biodiversity Action Plan (UKBAP) and included in English Nature's Species Recovery Programme (SRP). With a species as difficult to find as this fungus, it is important to establish, first of all, just how rare it is. The conservation body, Plantlife, have added the Devil's bolete to their 'Back from the Brink' project. Over the last few years, surveys have been carried out by a number of people to find examples of this fungus, and produce a clearer picture of its true range. While it is known to be rare in many of the European countries within its range, the Devil's bolete is not legally protected in any of them. However, many of the sites in the UK where it is recorded are now Sites of Special Scientific Interest (SSSIs), or listed for protection in the future.

See also Plantlife:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: