BRIEF DESCRIPTION: The following is based on the description by Bas (1969).

The cap of Amanita subalbida is about 30 - 45 mm wide, somewhat irregularly convex to plane with a slightly depressed center, dry, pallid brownish to nearly white, with a nonsulcate, slightly appendiculate margin.  The cap is covered with thin, pulverulent-subfelted, concolorous, crust-like remnants of volva especially over the center.

The gills are crowded, slightly adnexed, moderately broad, and white.  The short gills are truncate to rounded-truncate.

The stem is about 30 - 50 x 8 - 10 mm, equal, solid, white, and without any remnants of volva.  The stipe's basal bulb is subglobose to ellipsoid and 8 - 15 mm wide.

The spores measure 10 - 12.5 (-13.5) x 5.5 - 7 (-8) µm and are amyloid and ellipsoid to elongate.  Clamps are present, but rare, at bases of basidia.

Amanita subalbida was originally described from South Australia, and Bas knew it only from the type.