Beef-Steak Fungus

Description

The beefsteak fungus looks like a piece of raw meat or liver stuck to an oak trunk. The cap, usually 10–20 cm wide, is tongue-shaped or kidney-shaped, rough, red to purple-brown, cream-white underneath with fine pores. The flesh is juicy, marbled, exudes a red juice when cut, and has a sourish taste.

It grows on living and dead oaks, on trunks, roots and stumps, and in other countries also on sweet chestnut. It appears in summer and autumn.

The species is partially protected in Poland and regarded as rare, so collecting is restricted. Older ones may cause stomach complaints.

Identification features

Cap

Annual, width 7–30 cm (descriptions give different ranges), thickness 2–6 cm. Initially knobbly, then cushion-shaped, finally spatula-shaped, semicircular or kidney-shaped (tongue-shaped). Upper surface slightly radially streaked, ridged and warty, rough; pink or orange-red when young, later blood-red to purple-brown. Young caps exude abundant blood-red juice and resemble animal liver.

Hymenophore (underside of the cap)

Tubes compact, crowded, whitish to cream, yellowish, later rusty-brown; tube length — no reliable data. Pores fine, spherical, 0.2–0.3 mm in diameter. Hymenophore cream-white.

Stem

Lateral, short, 2–5 cm long, up to 4 cm wide (descriptions give different ranges), barely noticeable or absent.

Flesh

Thickness 2–6 cm; soft, fleshy when young, full of blood-red juice, flesh-red with marbled veins; pleasant smell, sourish taste. When cut it exudes a reddish juice that can stain.

Spore print and spores

Spore print colour: white or pinkish (descriptions differ). Spores ovoid, smooth, colourless, 4–6 × 3–4 µm.

Habitat and distribution

Ecology. A tree parasite and saprotroph. Grows singly or in clusters of several fused fruiting bodies on roots, trunks, stumps and windthrown trees of oaks, also on oak timber; according to some descriptions also on sweet chestnut, and in Australia on eucalypts. Causes brown rot of wood, decay progressing very slowly, even for several decades. Oak wood takes on a red tint, which increases its value in furniture making.

Distribution. Occurs in Europe, Africa, Australia, North, Central and South America and Asia. In Poland about 250 sites had been reported by 2020; on the Red List with the status R (potentially threatened). Protection: 1995–2004 partial, 2004–2014 strict, since 2014 partial (Dz.U. 2014 item 1408). Also on the threatened lists in Norway, Finland, Sweden and Lithuania.

Fruiting. In Great Britain and Europe from July (August) to October and until the end of autumn; exact data for Poland — no data.

What can it be confused with?

• Pseudofistulina radicata — Mentioned as a similar species; detailed differences — no data.
• Amylocystis lapponica, Ischnoderma resinosum, Leptoporus mollis, Rhodofomes cajanderi — Mentioned as similar; detailed differences — no data. The beefsteak fungus is distinguished by its fleshy, red fruiting body on oak, exuding a reddish juice.

Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.

Interesting facts

• The English name is beefsteak fungus, also ox tongue.
• The decay of oak wood by this fungus gives it a reddish-brown tint and increases the value of the wood in furniture making.
• In Poland the protection status has changed: 1995–2004 partial, 2004–2014 strict, since 2014 partial again.