Beefsteak fungus; Ox tongue
Oak and sweet chestnut.
Other deciduous broadleaves, including beech, albeit very infrequently.
Growing from bark-less areas of the tree from the buttress roots up into the crown.
Annual . Soft and fleshy. Upper surface a strong pinkish-red that sometimes exudes red liquid. Pore surface off-white. Flesh pink and similar to to liver (hepatic) – quite stringy. Desiccates to a dark reddish-brown to black before generally disintegrating. Often parasitised by blue moulds. Anamorphic state (Confistulina hepatica) lacks a pore surface and can adopt aberrant forms (photo b,c).
Generally not considered to be pathogenic, with gradual decay restricted to the heartwood . Attributed to a brown rot with some soft rot qualities in early / novel stages. Anecdotal evidence suggests this fungus can cause burring on oaks when it breaks through to the sapwood . Long-standing decay can cause structural failure. Remains largely benign, as regards its impact upon the tree.