concentrica (King Alfreds Cakes, Cramp Balls, Coal Fungus) — Species | WeMush Taxonomy

concentrica

King Alfreds Cakes, Cramp Balls, Coal Fungus

Daldinia concentrica is a distinctive pyrenomycete fungus in the family Hypoxylaceae (formerly Xylariaceae), widely known for its hard, carbonaceous stromata that resemble lumps of coal. The fruit bodies are hemispherical to globose, ranging from 2 to 10 cm in diameter. Young specimens are reddish-brown and covered in conidia (asexual spores), while mature specimens turn shiny black and develop a pimpled surface due to the ostioles of embedded perithecia. A defining characteristic is the internal flesh, which displays alternating concentric zones of silvery-grey and black texture, resembling tree rings; these zones are linked to seasonal growth cycles and water retention.

Edibility: Not recommended. The species is inedible due to its hard, woody, and carbonaceous texture. While not poisonous in the sense of containing deadly toxins, it is indigestible. Historically, it has been used as tinder for fire-starting rather than as food. Safety: Spore release can be extremely profuse, coating surrounding surfaces in black dust. Inhalation of dense spore clouds should be avoided.

Habitat: Saprobic on dead or decaying hardwoods, particularly in deciduous woodlands. It is often an endophyte in living tissue, fruiting only after the host branch or tree dies or is stressed by fire.. Substrates: Fraxinus (Ash) - primary host in Europe, Fagus (Beech), Betula (Birch), Burnt wood. Conditions: Tolerates dry conditions well due to internal water retention; fruits on exposed dead wood.. Season: Perennial fruit bodies; spore release typically occurs from late spring through autumn, often nocturnally.

Difficulty: INTERMEDIATE

Growth: moderate

Contam Risk: low

Cultivation Suitability

Preferred Substrates

Malt Extract Agar (for mycelium)

Ash sawdust

Hardwood dowels

Distribution

Native: Europe (Type locality), United Kingdom, Temperate Asia. Introduced: Various temperate regions globally (though often confused with local lookalikes). Widespread in temperate zones. Note: In North America, the lookalike species Daldinia childiae is far more common, while true D. concentrica is rare or absent.

Known Strains (0)

No strains cataloged yet for this species.

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