Agarikon

Description

Agarikon forms large, hard, perennial fruiting bodies shaped like a hoof or cylinder, attached sideways to the trunk, with no stem. Young ones are yellowish white, later chalky, and with age they turn grey and brown, crack into cubes and become brittle. The underside has small white pores. The broken flesh is white, cheesy and very bitter.

It grows on very old larches in forests of natural character, sometimes high on the trunk or branches. In Poland it is extremely rare, known from a dozen or so sites, including Góra Chełmowa in the Świętokrzyskie Mountains. The fruiting body is visible all year, and its presence indicates wood rot in the tree.

This is a strictly protected species; it must not be collected or damaged. It is not suitable for eating.

Identification features

Cap

Perennial fruiting body, without a stem, attached sideways to the trunk; usually hoof-shaped, becoming cylindrical after many years, sometimes fused with neighbouring fruiting bodies. It reaches up to about 65 cm in length (up to 1 m in height according to some descriptions), about 40 cm in thickness and a weight of up to about 10 kg. Young fruiting bodies are soft and yellowish white, quickly hardening and turning chalky. Older ones are grey, reddish or brown, brittle and cracked into cubes; thick white felty layers are visible in the deeper cracks. It grows in layers; the record specimen had 82 growth layers.

Hymenophore (underside of the cap)

Tubular. Tubes 3–20 mm long, often arranged in layers (successive annual growths). Pores white, small, 4–5 per mm (in extreme cases from 1). Spores are released through the underside of the fruiting body.

Stem

None; the fruiting body is sessile, attached sideways to the trunk or branch.

Flesh

White, brittle, cheesy, very bitter; the felt in the cracks has the same bitter taste. Smell mild to mealy. The flesh should not be tasted.

Spore print and spores

Spore print white. Spores ellipsoid, smooth, hyaline (colourless), with oil droplets, non-amyloid, 6–9 × 3–4 µm.

Habitat and distribution

Ecology. Parasite and saprotroph of wood, causing brown rot (brown, destructive rot) in the trunks of living trees. In Poland it grows exclusively on larches (Larix); in other parts of its range it rarely also occurs on fir, cedar, spruce, pine, Douglas fir and hemlock. In Europe it occurs mainly on very old larches in natural forests, very rarely in artificially regenerated stands; it is considered an indicator of old-growth forests. A fruiting body on a tree usually indicates extensive infection of the trunk; the dead tree can be a habitat for organisms that nest in deadwood.

Distribution. Wide range in the Northern Hemisphere: Eurasia, Morocco and North America. In Poland very rare: by 2020 it was known from 11 historical and 6 recent sites; the largest number of trees with fruiting bodies was observed in the "Góra Chełmowa" protected area in Świętokrzyski National Park. Under strict protection in Poland (since 1983; currently Dz.U. 2014 item 1408), it has category E (endangered or critically endangered) in the Polish Red List of Plants and Fungi and category EN (endangered) in the IUCN Red List. It is not on the list of fungi approved for sale in Poland. Legal protection also applies in, among others, Germany, Lithuania and Slovenia.

Fruiting. Perennial fruiting body, visible all year round; spores are released mainly in the warmer months.

What can it be confused with?

• Phellinus spp. (conks) — Fruiting bodies darker, more blackish, preferring hardwood (broadleaf) trees.
• Fomitopsis mounceae and related species — Similar fruiting body shape; distinguishing them requires assessment of the host, range and microscopic features. No detailed data.
• Ganoderma brownii — A North American species with a harder, darker fruiting body; it does not occur in Poland.

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

• Fruiting bodies can live up to 80 years; the largest known specimen had 82 growth layers and is kept at the University of Washington.
• Peoples of the North American northwest coast (Tlingit, Haida, Tsimshian) called it "bread of ghosts", carved masks from the fruiting bodies and used them to mark the graves of shamans.
• In Yakutia it was used to make soap.