BRIEF DESCRIPTION: Amanita murrilliana is similar to A. jacksonii Pomerleau and other of the "Slender Caesars" in many respects, but differs from most of them by lacking bright pigments and having the stipe base rather broadly attached to the volval sac (see photo).

The cap is 40 - 90 mm wide, has a central umbo, and is striate for about half of its radius.  The colors are cream or whitish near the margin and tan to brown in the center.

The gills are adnexed, crowded, and white.  The short gills are truncate and of diverse lengths.

The stem is 150 - 180 ´ 5 - 15 mm, white, and lacking colored decoration.  There is a small superior annulus on the stipe.  The volval sac is 40 - 90 mm high.  At the middle of its height, the volval limb may be as much as 4 mm thick.

The spores measure (8.5-) 9.5 - 12.6 (-13.6) x (5.6-) 6.4 - 8.4 (-9.2) µm and are ellipsoid to elongate (rarely broadly ellipsoid) and inamyloid.  Clamps are common at bases of basidia.

Other Western Hemisphere species in the "Slender Caesar group" (Amanita stirps Hemibapha) include A. jacksonii, A. arkansana Rosen, A. banningiana Tulloss nom. prov., and A. garabitoana Tulloss, Halling & G. M. Muell. nom. prov. The present species is known with confidence from the eastern U.S. from Florida to Maine and as far west as Michigan, and it is probably to be found as far north as Quebec.  It occurs with birch or in mixed forest with birch, conifers, and oak.
-- R. E. Tulloss