BRIEF DESCRIPTION: The following description is based on Reid (1980).

The cap of Amanita luteofusca is 30 - 56 mm wide, convex then plano-convex with its center slightly depressed.  It is viscid when moist, pale umbrinous to gray-brown with a yellowish tint or grayer and darker than Ridgeway's Pinkish-Buff.  The volva is rather uniformly distributed flat patches to scales that are farinose, gray (sometimes paler toward the cap margin), most densely placed in the center.  A thin, white layer of hyphae, sometimes appearing to be thin paper, may project from the edges of the larger scales or patches.  The flesh is thin.

The gills are moderately crowded, adnate, up to 9 mm broad, and white.

The stem is 56 - 80 x 5 - 10 mm, white, rather narrow, stuffed then finally subhollow, moderately narrowing upwards, minutely fibrillose.  The base of the stem is narrowly bulbous, but not abruptly so.  The ring is membranous, and sometimes left on the cap margin. The volva may be absent from the stem in some specimens, but is present as patches similar to those on the cap on the stem of other fruiting bodies.

The spores measure 7.0 - 11.0 x 7.0 - 9.2 µm and are globose to subglobose to broadly ellipsoid and amyloid.  Clamps are absent at bases of basidia.