We are regularly contacted by people who think they have found valuable, edible truffles. While some have successfully found them, many have actually found "truffle look-alikes", usually, but not always, other types of fungi that have a passing resemblance to truffles. These truffle look-alikes should not be eaten as many will cause stomach upsets. Some people have found truffles, though they could be species that are not eaten. We are happy to confirm ID - see this page.
Cramp Balls or King Alfred's Cakes
If what you have found is black (or pinkish-brown on younger ones) and:
- Growing on an Ash, Beech or other tree (above the ground)
- When cut in half shows concentric circles
it is probably a type of fungus - a Cramp Ball or King Alfred's Cake - do not eat!
Of the many types of truffle-like fungi which are often mistaken for them, are those of the genus Melanogaster. This name is from the Latin words for "Black" and "Stomach"! Internally they are almost marbled but the consistency is of jelly, not solid like a true truffle. They do not have the characteristic aroma and value of truffles, although some have been used culinary. None are known to be poisonous. Four or five species are known from the UK. The Bath Truffle was formerly eaten and sold in markets. One writer said in 1884 of the Stinking Slime Truffle "a single specimen in a room is so strong as to make it scarcely habitable” !!
If what you have found is on the roots of a tree it may be a plant gall. The most well known plant gall is the Oak Apple. Plant galls are abnormal growths of plant tissues, similar to benign tumours or warts in animals. They can be caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites. Many are found underground. Some may be black in colour, others lighter (see white truffles section below).
Another plant gall, thought to be a truffle by it's finder. Again found underground on the roots of a tree.
Earthballs look a little like a warty potato. They are fungi found on acid soils (e.g. wooded heathlands). They vary in colour from light brown to brown and usually have a yellow tinge. If you cut a mature specimen in half, it will be made of a black powder (the spores). An immature one will be white inside. An Earthball will give a stomach upset if eaten. You can see more images / learn more about the Earthball here.
You wouldn't confuse a fully-grown Stinkhorn fungus with a truffle. Their "phallic" appearance and foul-smell are very distinctive. At their immature stage they are a gelatinous, spherical, or egg-shaped structure which is completely or partially buried underground so finders can confuse them with truffles.
These are a comparatively common underground fungus that is widespread in England associated with deciduous trees but can be found with conifers. Veined Choiromyces are often irregularly shaped and can protrude through the ground surface and get quite big. Found in areas with acid soils they prefer clay. Sometimes confused with The Italian White Truffle (Tuber magnatum), their texture, aroma and flavour are completely different. The skin is smooth and white to yellowish brown and the inner is closely marbled of the same colours as the skin but with white veins. The smell is strong, aromatic at first, becoming unpleasant with age.
They should not be eaten as they reputedly cause stomach upsets.
Plant galls can be black or lighter in colour so have been confused with both black and white truffles. Black plant galls are shown (and introduced) above, lighter coloured ones here. The first one shown may be The Truffle Gall named because of the similarity of it's skin to that of certain species of truffle. It is caused by The Truffle Gall Wasp (Andricus quercusradicis) and was found on the roots of an English Oak tree.
Another plant gall confused with a truffle. This was found growing in a hedge above ground. It is a Crown gall.
Another plant gall. This one was underground on the roots of a tree.
This is an Alder root nodule gall - a type of plant gall found on the roots of a Alder tree.
Thank you to the finders of these truffle look-alikes for permission to use their photographs.