Beefsteak fungus (Fistulina hepatica): what the sources record

This page describes what three published sources say about one bracket fungus. It does not identify a fungus from a photo and says nothing about any single tree. Two of the sources are research papers, one on spore spread in oak stands in Lithuania and one on the fungus's genome, so they describe the fungus's biology and do not give tree-risk guidance. The parent page, wood decay fungi on trees, compares the fungi that have pages here.

Hosts and where it fruits

The Woodland Trust says the beefsteak fungus is common in the UK and is usually found in broadleaved woodland, low on the trunks of oak and sometimes on freshly cut oak stumps. It gives the fruiting season as late summer to autumn and says the bracket does not last through the winter. The Lithuanian paper, published in the journal Diversity in 2023, says the fungus mainly grows on older trees of oak (Quercus) and chestnut (Castanea), and rarely on maple, birch, hazel or beech. The authors report fruit bodies growing on the stems of living oaks at 0.5 to 1.0 m above the ground in all three of their study stands.

What the bracket looks like

The Woodland Trust describes a semicircular red, pink or brown bracket up to 25 cm across and 6 cm thick, moist or sticky to the touch, with cream pores underneath that turn reddish-brown with age. It says a young bracket looks like a tongue poking out of the trunk, and it names the yellow shaggy bracket (Inonotus hispidus) as a fungus not to confuse it with.

The rot it causes

The Woodland Trust says it causes a brown rot in oak that gives the timber the colour called brown oak. The genome paper, published in 2015 in Fungal Genetics and Biology and read here through PubMed Central, agrees that the fungus shows the features of brown rot in its genes and in the decay it causes. The authors add that its enzyme set is smaller than that of other brown rot fungi and suggest the move to brown rot may be an ongoing process in this species. On how the sources define brown rot beside white and soft rot, see white, brown and soft rot compared.

How the sources describe its progress in a tree

Lithuanian paper: says the fungus usually infects old living trees that have reached maturity, acting as a pathogen while causing the rot.
Lithuanian paper: says the fungus was not found in stem wounds of mid-age oaks, which the authors read as showing it may take many years to establish, cause rot and produce fruit bodies.
Lithuanian paper: says the fungus can develop in a tree for several decades before the wood structure is heavily affected, with decay usually in the central part of the stem and in rare cases up to six metres in height, and says hollow cavities can form as decay advances.
Lithuanian paper: says most spores landed within 50 m of the fruit body in the study, so the fungus depends largely on local habitats.

Status

The Lithuanian paper says the species is red-listed and protected in many countries, including Poland, Lithuania and some Scandinavian countries, because old-growth host trees are scarce. None of the three sources lists it as a regulated pest, and no report line applies on this page.

Where the sources differ

The Woodland Trust speaks of a woodland fungus on oak in the UK, while the Lithuanian paper also notes it in urban settings where suitable old trees stand. The three sources do not give a measured strength figure for oak affected by the fungus, so none is repeated here. For the credentials of people who examine trees see tree risk assessment methods.