Death cap

Description

The death cap is a large mushroom with a cap 5–15 cm across, usually in shades of green, olive or grey-green, sometimes almost white. It has white, crowded gills, a drooping ring on the stem and a bulbous base rising from a sac-like, whitish volva. The volva is often hidden in the leaf litter, so with every gilled mushroom you must carefully dig out the base of the stem.

It grows from June to November, most often under oaks, but also under beeches, birches, hornbeams and other trees, in deciduous and mixed woods, singly or in small groups. In Poland it is common.

It is easily confused with brittlegills, the man on horseback and young field mushrooms. The presence of a ring and a volva together with white gills is a clue, but you must not rely on a single feature. If you are not sure of the species, do not pick it and do not eat it. The poison cannot be removed in the kitchen.

Identification features

Cap

Diameter 5–15 cm; hemispherical when young, then bell-shaped to convex, finally flattened. Surface smooth, not striate at the margin, with radially arranged fibres, easily peeled, sticky when wet. Colour whitish-green, olive-green, grey-green or brownish-green, usually paler at the margin, sometimes yellowish; faded by sun, after rain and in old specimens. A completely white form also exists. White remnants of the universal veil may be present on the cap. Cap colour is variable and is not a diagnostic feature.

Hymenophore (underside of the cap)

Gills crowded, free (not attached to the stem), white, with a slight yellowish-greenish tinge in old specimens. Hidden under the veil in young fruiting bodies.

Stem

Height 8–15 cm, thickness 1–2 cm, cylindrical, whitish with a yellowish-green or grey-olive tinge; smooth above the ring, with fine scales below the ring, sometimes forming a zigzag pattern. Ring drooping, white to yellowish, about 1–1.5 cm below the cap. Base bulbous (up to about 4 cm), surrounded by a tall, whitish, sac-like, ragged and spreading volva, often hidden in the leaf litter — it must be uncovered for identification.

Flesh

White, does not change colour when cut. Smell weak and sweetish (honey-like) in young specimens, becoming stronger with age, sickly sweet and unpleasant; in old specimens sometimes described as smelling of potatoes. The taste is sometimes described as pleasant — it must never be tested; do not taste the flesh of this or any suspicious mushroom.

Spore print and spores

Spore print white. Spores smooth, broadly ellipsoid to almost spherical, amyloid (turn blue with iodine). Size: 7–12 × 6–9 µm (descriptions give different ranges; 8 × 11 µm and 8–10 µm are also found).

Habitat and distribution

Ecology. Mycorrhizal fungus (ectomycorrhiza). In Europe the main partner is oak, also beech, sweet chestnut, horse chestnut, birch, hazel, hornbeam, pine and spruce. Grows most often on neutral or alkaline soils, but also on acidic ones. In North America, populations associated with pine have been described.

Distribution. Native to Europe, where it is widespread from southern Scandinavia to the Mediterranean basin; common throughout Poland. Introduced to, among others, North America, Australia, South America, southern Africa and New Zealand; now found on all continents except Antarctica. Grows singly or in small groups, mainly in deciduous woods, also mixed woods. Not legally protected in Poland.

Fruiting. June to November.

What can it be confused with?

• Tricholoma equestre (man on horseback) — Gills yellow, not white; no ring or volva. Now considered dangerous after a series of poisonings in France.
• Russula virescens (green brittlegill), Russula aeruginea (grass-green brittlegill) — Flesh brittle, no ring or volva. The death cap has a ring, a volva and free gills.
• Agaricus campestris and other field mushrooms (especially young fruiting bodies and the white form of the death cap) — Mature field mushrooms have dark gills, while the death cap has white gills and a white spore print. In young specimens the gills are hidden, which makes mistakes more likely.
• Tricholoma portentosum (charbonnier) — The charbonnier has no ring and no volva at the base of the stem; the death cap has both.
• Amanita citrina (false death cap) — Sometimes confused with the death cap; detailed differences — no data.

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

• Responsible for about 90% of fatal mushroom poisonings worldwide; the lethal dose is considered to be about 30 g, i.e. about half a cap.
• The first scientific description comes from Sébastien Vaillant in 1727; phalloidin was isolated in 1937 and amatoxins in 1941.
• The fungus's own RNA polymerase is insensitive to amatoxins, so the fungus does not poison itself.
• It appeared on a Polish postage stamp from the "Mushrooms of Poland" series issued on 8 May 1959 (face value 20 gr).