Umbrella Polypore

Description

The umbrella polypore forms large clumps, even balls, 10-50 cm across, made of many small caps (1-4 cm) attached to a common, branched, whitish base. The caps are light brown, umbilicate and scaly. Underneath they have narrow, whitish pores on tubes running down the stem. The flesh is white, with a smell of dill.

It grows from June to October at the roots and trunks of living broadleaved trees (beeches, oaks, maples) and fruits in the same place for many years in a row. In Poland it is rare (status V - vulnerable) and since 2014 has been under partial protection.

It is most easily confused with the hen of the woods, whose caps are fan-shaped, irregular, without separate stems. If you are not sure of the species, do not pick or eat it.

Identification features

Cap

A compound fruiting body: from a common, branched base grows a dense mass of numerous (sometimes several hundred) caps forming an irregular spherical clump 10-50 cm in diameter (some descriptions give up to 40 cm). A single cap 1-4 cm, irregular, deeply umbilicate, surface fibrous-suede-like, cracked into scales, scales ochre-brown to grey-brown (light brown).

Hymenophore (underside of the cap)

Tubes 1-1.5 mm long, straw-yellow, running far down the stem; pores narrow, whitish.

Stem

Whitish, sometimes cream or white-grey, 2.5-7 cm, irregularly fused with neighbouring stems, growing from a branched, fleshy, tuberous base - a sclerotium - which takes up nutrients from the substrate. No ring.

Flesh

Whitish, soft and fleshy, hardening with age. Smell pleasant, reminiscent of dill; do not taste the flesh of unidentified mushrooms).

Spore print and spores

Spore print white. Spores cylindrical, smooth, colourless, 7-10 × 3-4 µm.

Habitat and distribution

Ecology. A terrestrial saprotrophic fungus; grows on the roots and at the trunk bases of living broadleaved trees (maple, beech, oak; according to some descriptions also old beeches and oaks). The sclerotium is a storage organ. It fruits in the same place for many years.

Distribution. Rare in Poland: about 100 sites up to 2020. Red list 2006: V (vulnerable). On lists of threatened species also in Austria, Belgium, Germany, Denmark, Estonia, Lithuania, Norway, the Netherlands, Sweden and Finland. Under strict protection in 1983-2014, since 2014 under partial protection (Dz.U. 2014 item 1408); harvesting of fruiting bodies for commercial purposes is permitted after obtaining permits. Also occurs in eastern North America.

Fruiting. From June to October; from May to September in eastern North America.

What can it be confused with?

• Grifola frondosa (hen of the woods) — Single caps spatula-shaped, fan-shaped or wedge-shaped, of irregular sizes, without centrally attached stems (in the umbrella polypore the caps are umbilicate, with a central stem, and more even in size).
• Armillaria tabescens — Has gills, not tubes with pores.

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 fruiting body sometimes consists of several hundred caps growing from one common, branched base.
• It fruits in the same place for many years because it has a storage sclerotium.
• In Poland it was under strict protection in 1983-2014; about 100 sites were known up to 2020.
• In Chinese medicine the sclerotium (a compact mass of mycelium with reserves) is used, not the caps themselves.