Trametes gibbosa

(Pers.) Fr.

On a sheared stem likely caused by Kretzschmaria deusta on beech in the New Forest, Hampshire.
Young brackets on hornbeam coppice in Parndon Wood, Essex
Algal-stained over-mature brackets on hornbeam coppice in Hockley Woods, Essex
Fruiting bodies destroyed by insect borers on a beech stump at Hampstead Heath, London
White flesh and tube layer as taken from a fruiting body on beech in Winchester, Dorset

On a sheared stem likely caused by Kretzschmaria deusta on beech in the New Forest, Hampshire.
Young brackets on hornbeam coppice in Parndon Wood, Essex
Algal-stained over-mature brackets on hornbeam coppice in Hockley Woods, Essex
Fruiting bodies destroyed by insect borers on a beech stump at Hampstead Heath, London
White flesh and tube layer as taken from a fruiting body on beech in Winchester, Dorset
A fruit body destroyed by boring and feeding insects in Hampstead Heath, UK.
Showing the striking detail of this species including distinct greening.
Developing fruit bodies on beech with visible zoned colourations in the New Forest, UK.
Flushed white brackets on poplar in Barnet, UK.
Senescent fruit bodies on poplar in Barnet, UK.

Common name

Lumpy bracket; Stump-grinder fungus.

Often found on

Beech, birch, hornbeam, horse chestnut.

Sometimes found on

Cherry, oak, and other broad-leaved species.

Location

Found across the entire scaffold structure of the tree – often on fallen trees and tree parts.

Description

Annual or Perennial. Tough and woody. A little bendy under pressure. Usually in clusters. Quite thick. Can become fair-sized. Upper surface off-white and sometimes slightly hairy and becoming greenish with age towards the centre. Pore surface off-white. Tubes irregular, sometimes elongated and sometimes slotted. Flesh white. Spore white. Anamorphic version appears as a white ‘frassy’ mass with sometimes abundant insect boring. Over-mature brackets can become very dark green and gradually disintegrate into frass.

Confused with

Trametes pubescens (more downy on the upper surface); Trametes suaveolens (often on willow and smells of aniseed); Trametes versicolor (much smaller).

Significance

Attributed to a white rot of the wood. Saprobic. On standing trees, presence of this fungus indicates localised dysfunction. Very unlikely to be a principal cause of failure. If found abundantly, large dysfunctional areas likely are present and structural investigations may be required, should the crown condition be acceptable. Indicative of moderate and advancing decay stages because this fungus follows (and temporarily parasitizes) Bjerkandera adusta.