Kretzschmaria deusta

(Hoffm.) P.M.D. Martin

The anamorphic stage of this fungus growing on fallen beech in the New Forest, Hampshire.
The early anamorphic stage on a buttress root of horse chestnut at Pishiobury Park, Hertfordshire
Growing out on a surface root peripheral to a mature beech in the New Forest, Hampshire
Mature teleomorphic fruiting bodies at the base of a beech in the New Forest, Hampshire
Black pseudosclerotic plates on a beech cross-section taken following the felling of the tree

The anamorphic stage of this fungus growing on fallen beech in the New Forest, Hampshire.
The early anamorphic stage on a buttress root of horse chestnut at Pishiobury Park, Hertfordshire
Growing out on a surface root peripheral to a mature beech in the New Forest, Hampshire
Mature teleomorphic fruiting bodies at the base of a beech in the New Forest, Hampshire
Black pseudosclerotic plates on a beech cross-section taken following the felling of the tree
Senescent fruit bodies on sycamore in Essex, UK.
Emerging fruit bodies on beech in the New Forest, UK.
Abundant fruiting at the base of beech at Burnham Beeches, UK.
Various stages of fruit body development on beech at Epping Forest, UK.
Very fresh fruit bodies still tinged beige on chestnut in Sawbridgeworth, UK.

Common name

Brittle cinder.

Often found on

Beech, horse chestnut, lime, sycamore.

Sometimes found on

Ash, birch, hornbeam, maples, wild service, and other broadleaved species.

Location

Found fruiting on surface roots and around the base of the tree most often – sometimes fruiting up to 3m and around old (lapsed) pollard heads.

Description

Annual. Anamorphic stage in spring is a brownish-white to greyish-white, which soon develops into a grey mass with a white perimeter. Teleomorphic stage from late summer is charcoal black and crumbles when crushed – hence its common name. Grows against the wood surface – does not form brackets. Cross-sections show black zonation (pseudosclerotic plates).

Confused with

Daldinia concentrica; Hypoxylon fragiforme; Hypoxylon multiforme

Significance

Attributed to a soft rot of the wood with later-stage white rot. Considered to often enter following wounding to the stem or roots. Able to breach reaction zones on the host tree and is thus able to act pathogenically. Clustered outbreaks have been observed. May also act saprotrophically, on dysfunctional and dead areas of a living tree. When found, investigations into remaining wood strength may be required, subject to a target existing within falling distance. Attributed often to the ceramic-like failure of trees at the butt and at lapsed pollard heads. More virulent during drought.