BRIEF DESCRIPTION: The fruiting bodies of Amanita yuaniana are medium-sized to large.  The cap is 70 - 130 mm wide, convex to planate, not umbonate, grey, grey-brown, brown to sepia, with white to whitish spots, innately fibrillose, usually glabrous, occasionally with a few white, membranous volval remnants; the cap margin is short striate (up to 10%, rarely 20% of radius) and non-appendiculate; its context is white.

The gills are free to nearly free, crowded, white, with greyish edges; the short gills are truncate.

The stem is 70 - 140 x 10 - 25 mm, subcylindrical or slightly tapering upwards, white to greyish, glabrous or covered with white to greyish fibrillose squamules; the context is white and fistulose; the stipe lacks a basal bulb.  At the stipe's base, the volva is saccate, 40 - 60 x 40 - 50 mm, membranous, 1 - 3 mm thick, with both surfaces white to dirty white.  Sometimes the upper part of the outer surface is greyish. The volva has a white to greyish internal limb.  The species has a superior annulus that is membranous; its upper surface is white to greyish, with fine radial striations; its lower surface is grayish and fibrillose.

The spores measure (8.5-) 9.5 - 12.0 (-13.0) x (6.0-) 6.5 - 8.0 (-9.5) µm and are ellipsoid and inamyloid.  Clamps are common at the bases of basidia.

Amanita yuaniana is edible and can be found in free markets during rainy seasons.

This species was originally described from Sichuan Province, China, and is common in southwestern parts of the country. -- Zhu L. Yang

Note: The species is assignable to stirps Hemibapha. - RET