BRIEF DESCRIPTION: Fruiting bodies of Amanita castanopsis are usually medium-sized.

The cap of this specie is 50 - 110 mm wide, convex to applanate, white, and covered with white to dirty white conical to conical to sub-pyramidal volval remnants 2 - 5 mm high and 2 - 8 mm wide at their base, the tips of which are greyish to brownish.  The cap margin is nonstriate and appendiculate; and the flesh of this species is white.

The gills are free to subfree and white to cream; short gills are attenuate.

The stem is 70 - 120 x 10 - 25 mm and slightly tapering upward, with its surface and context white; the stem's basal bulb is 20 - 40 mm wide, spindle-shaped to turnip-shaped, with its upper part covered with whitish, granular to subconic to pyramidal volval remnants in belts.  The annulus is subapical, white, and fugacious.

Spores measure (8.5-) 9.0 - 11.0 (-12.5) x (4.5-) 50 - 6.5 µm and are ellipsoid to elongate and amyloid.  Clamps are common on bases of basidia.

This species was originally described from Japan in association with Asian Chinkapin (Castanopsis).  It is widely distributed in China, Japan, and Korea in deciduous forests that include fagaceous (Beech-Oak family) plants. -- Zhu L. Yang