Fool's Webcap

Description

The fool's webcap is a small mushroom with a cinnamon-brown or reddish-brown, dull and felty cap 3–8 cm across, with a blunt boss in the centre. It has sparse, thick gills, at first saffron-yellow, then orange to rusty, and a yellowish-brown, fibrous stem without a ring. The flesh smells faintly of radish.

It grows from August to October in deciduous and mixed woods, most often under oaks, less often under beeches and birches. In Poland it is rare and is on the Red List.

It is sometimes confused with chanterelles and other russet mushrooms. It contains orellanine, a poison that damages the kidneys and is not destroyed by cooking; the first symptoms appear after several days, so the poisoning is easily overlooked. In Poland in the 1950s there were two waves of poisonings in which about 10 people died. Do not pick webcaps for eating.

Identification features

Cap

Diameter 3–8 cm. Hemispherical or bell-shaped when young, then convex with an inrolled margin and a blunt umbo (sometimes concave, flattened with age). Surface dull, felty with fine scales, becoming smooth with age. Colour cinnamon-brown, reddish-brown or brown, orange-brown. The cap surface turns black with KOH.

Hymenophore (underside of the cap)

Gills at first saffron-yellow or pale ochre, then orange to orange-rusty, rusty-brown with age; convex, sparse and rather thick, broadly adnate to the stem or slightly decurrent (also described as adnate or notched).

Stem

Height 5–10 cm, thickness 1–2 cm, cylindrical, tapering at the bottom, solid; yellowish or yellowish-brown with darker longitudinal fibres, yellowish at the top. Sometimes remnants of a pale yellow veil (cortina) in the lower half; no ring.

Flesh

Yellowish to pale ochre, firm. Smell weak, similar to radish (especially when cut); taste mild or slightly sour — it must never be tested; do not taste the flesh of any suspicious mushroom.

Spore print and spores

Spore print rusty-brown. Spores ellipsoid or almond-shaped, slightly warty, 8–11 × 5.5–7 µm.

Habitat and distribution

Ecology. Mycorrhizal fungus. Grows in deciduous and mixed woods, especially under oaks, less often under beeches and birches; also under hornbeam, often near pines. Also described as common in lowlands, foothills and mountains (descriptions differ as to frequency).

Distribution. Europe (mainly Central and Eastern Europe, including Poland, the Czech Republic and Slovakia; rare in Germany; sporadic in southern Great Britain) and British Columbia. Rare in Poland; on the Red List of Plants and Fungi of Poland (2006) it has status R (potentially threatened because of its limited range). It is also on lists of threatened species in Switzerland, Germany, Denmark, the Netherlands, Norway and Sweden. Not legally protected.

Fruiting. August to October.

What can it be confused with?

• Cortinarius rubellus (deadly webcap) — More distinct boss, stem swollen at the base, gills without an orange tinge; grows in coniferous forests. Also deadly poisonous.
• Cortinarius semisanguineus (surprise webcap) — Redder gills, grows in coniferous forests.
• Cantharellus cibarius (chanterelle) — The chanterelle has ridges (false gills) running down the stem, not true gills, and an egg-yolk-yellow colour; the webcap has a rusty-brown spore print. Confusion with the chanterelle caused poisonings in Austria in 1997.

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 toxicity of the fool's webcap was discovered only in 1957; before that, webcaps were considered non-poisonous. In 1952 in Bydgoszcz, 102 people fell ill after eating it, and 11 died.
• In Poland at the end of the 1950s two waves of poisonings were recorded in which about 10 people died.
• Orellanine has a cumulative effect: repeated ingestion of even small doses intensifies the symptoms.
• In 1997 four people in Austria suffered kidney damage after eating it in the mistaken belief that they were chanterelles.