Kingdom: Fungi
Phylum: Basidiomycota
Class: Basidiomycetes
Order: Agaricales
Family: Pluteaceae
Genus: Amanita

The cap color is variable, but is typically olive-green with a metallic sheen. However, the cap color can be yellow green to yellow, grayish, brownish or even pure white. The cap often appears to have dark fibers, but these are due to narrow bands of pigment rather than actual fibers.

The cap is often palest at the margin (for example white or extremely pale yellow or extremely pale yellow green). The cap starts out egg shaped, exapands to rounded and eventually can become nearly flat. The cap is typically smooth and shiny when dry and can become a bit sticky when moist. At times the enclosing volva leaves a white patch on material on the cap.

The flesh is white and unchanging when cut or bruised. The gills are white to cream, crowed and free to narrowly adnate.

The stem is white to pale yellow below the ring, sometimes more strongly yellow near the stem base, sometimes with faint yellowish white areas above the ring. The ring is typically on the upper part of the stem and forms a membranous veil often with fine striations. The base of the stem usually forms a bulb which is wrapped in a sack-like volva.

The odor is sometimes absent in early development, becoming strong and unpleasant in age.

For a more detailed description see Rod Tulloss’ Amanita Studies Site.

Amanita phalloides was originally described from Europe where it is believed to be native. However, it has spread through much of the world through transplanted trees. It has been recorded in the US (western and eastern), Canada, New Zealand, Tanzania and Argentina.

In Europe in occurs with beech (Fagus), oak (Quercus), pine (Pinus), chestnut (Castanea), horse chestnut (Aesculus), birch (Betula), filbert and hazelnuts (Corylus maxima), iron wood or hornbeam (Carpinus), and spruce (Picea). In the northern hemisphere the present species when transplanted can spread to local trees of the same genera in addition to Canadian hemlock (Tsuga). It is reported under Leptospermum in New Zealand and under Eucalyptus and leguminous trees in Tanzania. Importation in the western hemisphere has occurred from Canada to Argentina.

In the western United States it is typically found with coast live oak (Quercus agrifolia).

Most commonly mistaken for other Amanita or Volvariella species. However, it has been reported being confused with a fairly wide range of other species including the gypsy mushroom (Cortinarius caperatus == Rozites caperata).

This species is considered one of the most deadly mushroom species in the world. It contains deadly amatoxins that can cause major damage to the liver and other internal organs.