King Alfred's cakes (Daldinia concentrica)

Also known as: Cramp balls
GenusDaldinia (1)
SizeDiameter: 2-7 cm (2)

Widespread (3).

King Alfred's cakes, also known as 'cramp balls' is a hard, inedible ball-shaped fungus (4). The visible part of the fungus, the fruit-body is initially reddish-brown in colour, but becomes black and shiny as it ages (2). The flesh is purple-brownish in colour (4), and dark concentric rings are visible when the fungus is cut open (3). The name 'cramp balls' refers to the belief that this fungus protected against cramp; men used to carry them around in their pockets for this reason (4).

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 common throughout Europe, North America and Australia and also occurs in New Zealand (4).

King Alfred's cakes are found growing on the dead branches of deciduous trees, particularly ash, but can also occur on beech and alder (4).

Fungi are neither plants nor animals but belong to their own kingdom. They are unable to produce their own food through the process of photosynthesis, as plants do; instead, they acquire nutrients from living or dead plants, animals, or other fungi, as animals do. In many larger fungi (lichens excepted) the only visible parts are the fruit bodies, which arise from a largely unseen network of threads called 'hyphae'. These hyphae permeate the fungus's food source, which may be soil, leaf litter, rotten wood, dung, and so on, depending on the species (3).

This species occurs throughout the year (3). During spring (2), it can be found covered in a layer of sooty black spores; these are released at night and can travel up to 2 cm away from the fruit body from which they were discharged. It is also believed by some authorities that the alder wood wasp is involved in the dispersal of spores. Timber infected by this fungus develops a white rot known as 'calico wood' (4).

This fungus is not threatened.

Conservation action has not been targeted at this species.

For more information on King Alfred's cakes, see:

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:

  1. National Biodiversity Network Species Dictionary (Jan 2003):
  2. Jordan, M. (1995) The encyclopedia of fungi of Britain and Europe. David and Charles, Devon.
  3. Courteciusse, R. (1999) Mushrooms of Britain and Europe. Harper Collins Publishers, London.
  4. Dickinson, C. and Lucas, J. (1979) The encyclopedia of mushrooms. Orbis Publishing, London.