How to tell Orange grisette from Death cap

The cap is 5 to 12 cm across, egg-shaped as it breaks out of the sac, then bell-shaped and convex, finally flat with a low, darker central bump.

It's yellow-orange to orange-brown with an apricot tinge in the centre, paler towards the edge. The surface is smooth and shiny, slightly sticky when wet, and almost never carries patches of veil. The edge is grooved like a comb.

The death cap's cap is 5–15 cm across, hemispherical when young, then opening out flat.

Its colour ranges from olive green and yellowish green to greyish and almost white, which is exactly what makes it tricky to identify. The surface is smooth and a little slimy in wet weather, with a characteristic pattern of darker fibres radiating from the centre. The margin is even, with no striations.

The gills are free, crowded, white to cream, with shorter gills of varying length in between.

The spore print is white.

The gills are crowded, thin and free, meaning they don't touch the stem. They're white and may turn creamy with age, sometimes with a faint pinkish tinge, but they never turn chocolate brown.

It never has the chocolate-brown gills of a mature Agaricus. The gap between gills and stem is clear. In young mushrooms a white, membranous veil covers the gills completely.

The stem is 10 to 15 cm tall, up to 20 cm, and 1 to 2 cm thick, tapering upwards, hollow and brittle with age, pale to deep orange with a white-and-orange zig-zag pattern of soft scales, like snakeskin. There's no ring and no bulb.

At the base is a large, thick, loose white sac (volva), often lobed and hidden in the soil.

The stem is slender, 7–15 cm tall and 1–2 cm thick. It's cylindrical and swells at the base into a characteristic club-shaped bulb wrapped in a membranous, sac-like volva. That volva is the main diagnostic feature.

It's whitish green, often with a faint, banded snakeskin pattern. A well-developed white ring, left over from the veil, hangs in the upper third. Below the ring the surface is faintly scaly.

The flesh is thin, white, soft and fragile, and doesn't change colour when cut.

The flesh is white and doesn't change colour when cut, and that's the treacherous part: none of the safety signs foragers usually rely on work here. It's thin and brittle in the cap, thicker and firmer at the base of the stem.

It doesn't darken in the air, not after a minute and not after an hour. Don't let "lovely white flesh" reassure you: the white flesh of the death cap is exactly where amanitins are most concentrated.

The smell is faint: some sources call it sweet and mushroomy, others indistinct.

Fresh, it has a faint smell that's easy to miss, and young ones barely smell at all. Mature mushrooms pick up a slightly sickly-sweet note, like wilted honey or stale dough.

That smell isn't strong enough to warn an inexperienced forager. Like other poisonous amanitas (the fly agaric, the panther cap), the death cap smells faint and nondescript, so it gives you no warning at all, which is one more treacherous trait. Only rotting mushrooms smell any stronger.