Giant polypore
Meripilus giganteus
Eating this will make you ill. Listed here so you can recognise and avoid it.
A very large annual bracket that forms one fan-shaped rosette of overlapping tan fronds, often 50cm to a metre across, at the foot of a broadleaf tree. The flesh and pores bruise black within minutes of handling, which is the feature that settles it against every other big clustered polypore. Edible when young and thoroughly cooked, though the flavour is sour and a fair number of people find it indigestible.
Saprotrophic and weakly parasitic on the roots, buttresses and stumps of broadleaf trees, above all beech and less often oak. Widespread across UK and Irish woodland and parkland, and frequent on mature churchyard and street trees.
Best treated as edible only with caution: reports of stomach upset are common enough that a small, well-cooked portion is the sensible first trial. Take only the pale, pliable outer frond margins of a fresh flush; older blackening brackets are sour and leathery. Fruiting bodies often sit on trees with advanced root decay, so watch overhead for dead limbs.
Always use more than one reference to confirm a plant. You are responsible for what you choose to forage.
A single huge rosette at the base of a tree
Dozens of fan-shaped fronds emerge from one common stem base to form a clump often 50cm and sometimes over a metre across. It is one fungus, not a colony of separate brackets stacked up a trunk, and it sits at ground level rather than partway up the tree.
Stains black when bruised
Press the pore surface or cut the flesh and the damaged area darkens through grey to black within minutes. This is the decisive test: a large tiered rosette at a tree base that shows no blackening at all is something else.
Fine whitish pores underneath
The underside is a cream to pale buff layer of very small pores, roughly three to five per millimetre, running down onto the branching stem. There are no gills and no separate stalk for each frond.
Tan fronds with radial wrinkles
Each frond is ochre to mid-brown, thin at the wavy edge and marked with fine lines running outwards from the base, often with faint concentric zoning. Fronds are pliable when young and become leathery and split-edged with age.
Beech first, oak second
Nearly all UK finds are on beech, with oak a distant second. The host tree is worth recording before anything else, because it narrows the possibilities faster than any feature of the fungus itself.
Sheer bulk — often a metre across
A single mature rosette can weigh several kilos and spread wider than a dinner table, far larger than any Hen of the Woods or Cauliflower Fungus you are likely to meet. Size alone should make you look for the blackening reaction before anything else.
All fronds rise from one fused base
There is no true stem and no branching stalk system; the fronds emerge from a common fleshy stump pressed against root or soil. Umbrella Polypore, by contrast, has many small circular caps each on its own branch of a pale branched stalk.
A marker of root and butt decay
It fruits on trees whose roots and lower trunk are already breaking down, and the crown above may still look sound. Worth noting where it grows rather than clearing the whole flush, and worth standing clear of the tree in wind.
Collapses to a black mass late in the season
Unlike the perennial hoof-shaped brackets, this is an annual fungus that darkens, softens and slumps into a sour black heap after the first frosts, leaving nothing woody behind.
Updated 2026-08-08T12:03:11.779Z · Added 2026-07-19T11:34:52.471Z
Part of the shared Foragers Log catalogue · Fungus