BRIEF DESCRIPTION: Amanita protecta is a member of section Vaginatae. It is a medium- to large-sized mushroom with gray to gray-brown, 40 - 152 mm wide cap.  A robust volva leaves thick, felted/fibrillose patches over a layer of fine pulverulence on the cap.

Gill of this species are free to very narrowly adnate with a white decurrent line on stipe and are close to subdistant.  They are white with dark gray or gray-brown margin, unchanging, and 4.5 - 12.5 mm broad, with minutely fimbriate edge (10× lens).  Short gills are not numerous, truncate to  concave-truncate, and occasionally anastomose with neighboring gills.

The 75 - 152 × 10.0 - 29 mm, pallid gray to whitish, exannulate stem is covered for much of its length with dark gray to black fibrils; and has a thick, lobed, cup-like volva on the stem base, with the highest point of the volval limb reaching to 20 - 40⁺ mm from the stem base; the limb is up to 5 mm thick at its point of connection to the stem.  The volval limb is rather widely separated from the stem by a gap partially due to the fact that the inner 1 - 2 mm of the volva is carried up on the expanding cap.

All parts of the basidiocarp have a tendency to develop ochraceous stains when damaged and due to aging.

The spores of A. protecta are (8.7-) 9.5 - 13.0 (-20.5) × (7.3-) 8.7 - 11.5 (-16.2) µm, inamyloid, and globose to subglobose to broadly ellipsoid (infrequently ellipsoid).  While the authors of this species reported rare clamps in some tissues, clamps were not reported to occur on the bases of basidia.  It would be wise to reassess the issue of presence of clamps in A. protecta.

The species is known from California, USA (at least as far north as Sonoma Co.), and its range probably extends into Baja California, Mexico.  It is associated with Coastal Live Oak (Quercus agrifolia) and Monterey Pine (Pinus radiata).

RET's impression is that the species is rather isolated within sect. Vaginatae; no similar taxa are known at present. -- R. E. Tulloss