BRIEF DESCRIPTION: The description is largely based on the original description (Wood 1997).

The cap of Amanita conicogrisea is up to 55 mm wide, convex then plane, smooth, dry, dull-cream to cream gray, with a slightly striate margin, with volval remains as scattered fine warts, mostly more or less pyramidal, and concolorous with the cap surface.

Gills are free, thin, crowded, pale cream, with a concolorous margin. The short gills are present in at least one series.

The stem is >up to 70 × 10 mm, equal, firm, smooth, white, with no trace of a ring, not obviously mealy, with the base not swollen. The volva is present as a little fibrillose margin on the upper portion of the bulb, more or less colored like the cap.

The spores measure 9.9 - 11.7 × 7.2 - 8.7 µm and are ellipsoid [probably sometimes broadly ellipsoid] and inamyloid.  Clamps are absent at bases of basidia.

Wood describes the mushroom as occurring in sclerophyll forests from the state of New South Wales, Australia. A sclerophyll forest in the Australian bush is a forest of hard-leaved plants including Eucalyptus in the overstory (wikipedia). This species was described from a single collection.