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.