How to tell Imperial mushroom from Death cap

The death cap's cap is 5–15 cm across. In young mushrooms it is hemispherical, later becoming flat and spread out.

The color varies from olive green and yellowish green to grayish and almost white — which is what makes identification tricky. The surface is smooth, slightly slimy in wet weather, with a characteristic radial pattern of darker fibers spreading from the center. The cap margin is even, without striations.

Cap very large: 10-30 cm across, hemispherical in young mushrooms, later convex-spreading, with a broad low hump in the center. Color gray-brown, mouse-brown, chocolate-gray, darker in wet weather and paler in dry weather. Surface smooth, with adpressed grayish scales in young mushrooms, bare in mature ones. Cap skin tough, does not peel. Cap margin thin, inrolled in young mushrooms.

The hymenophore is lamellate. The gills are crowded, thin and free — not attached to the stem. In both young and mature mushrooms they stay pure white — this is a critical diagnostic feature.

Not a hint of pink, cream or ochre, as in true Agaricus mushrooms. The gap between the gills and the stem is clearly defined. The veil is white and membranous, completely covering the hymenophore in young specimens.

Gilled hymenophore. Gills crowded, adnate or slightly decurrent down the stem. Color whitish to cream, with an ochre tint in old mushrooms. Spore print white — an important feature.

The stem is slender, 7–15 cm tall and 1–2 cm thick. Cylindrical, widening at the base into a characteristic club-shaped bulb wrapped in a membranous sack-like volva — the main diagnostic feature.

The color is whitish green, often with a snakeskin pattern of faint bands. In the upper third there's a well-developed, hanging white ring with remnants of the veil. The surface below the ring is faintly scaly.

Stem sturdy and fleshy: 8-15 cm tall, 3-6 cm thick, cylindrical or thickened toward the base, often with a rooting extension (pseudorhiza) deep into the soil. Color white to grayish-cream. A characteristic feature — the double ring: a broad membranous ring of two layers, whitish-gray above and darker below. This is the source of the confusion with amanitas, whose ring is usually single.

The flesh is white and doesn't change color when cut — and that's the treacherous part: none of the safety signs foragers are used to relying on work here. The flesh is thin and brittle in the cap, fleshy at the base of the stem.

It doesn't change color on contact with air, neither after a minute nor after an hour. No "lovely white flesh" should reassure you — it's precisely in the white flesh of the death cap that the concentration of amanitins is highest.

Flesh thick, white, very firm and meaty. Does not change color when cut. Raw, it has a pronounced mealy-cucumber smell; after cooking the aroma softens.

The smell of a fresh mushroom is faint and hard to notice; in young specimens it's almost absent. Mature ones develop a slight sickly-sweet note, like wilted honey or stale dough.

This aroma isn't distinct enough to warn an inexperienced forager. Like other poisonous amanitas (the fly agaric, the panther cap), the death cap has only a faint, indistinct smell that gives no warning — yet another treacherous trait. A stronger odor appears only in rotting specimens.

Strongly mealy-cucumber, peculiar — some like it, some don't. In amateur retellings it is sometimes described as "fresh flour" or "old sawdust". Mild taste; after boiling — pleasantly mushroomy.