Amanita phalloides, commonly known as the Death Cap is a medium to large, fleshy agaric with a greenish olive cap, whitish stem, and ring, no patches but a distinctive volval sheath. As the volva, which may be hidden by leaf litter, is a distinctive and diagnostic feature. It is important to remove some debris to check for it.

Cap at first round to egg-shaped and then flat and varies greatly in colour from grey-white to green and yellow-brown, with darker innate radial fibrillae, which start from the centre and branch out towards the margin. Sometimes with lots of veil remnants. The margin is usually not striate. The flesh is white throughout, unchanging when sliced. Gills free, close or crowded, broad, white but sometimes with a slight greenish tint. Stem more or less equal, or it may taper towards the apex and flare towards the swollen base. The stem also features a white, skirt-like ring that typically persists but can sometimes be lost. Finally, the stem has a sack-like white volva that encases the base, which may be visible above ground or may be broken up or underground. Spore print white.

Microscopic Features: The spores are ellipsoidal to subglobose in shape, with a smooth surface. They measure 7.5-10 µm in length and 6-7 µm in width. They are inamyloid.

Amanita phalloides on the First Nature Web site.
Amanita phalloides on the MushroomExpert.Com Web site.

The first photo is by Archenzo under the CC BY-SA 3.0 license.