BRIEF DESCRIPTION: The cap of Amanita chepangiana is 130 - 190 mm wide, often pure white, sometimes with a slight grayish, brownish, or yellowish tint over the center. This species is one of the "Slender Caesar group" that has a cap that is not umbonate.

The gills are free, close to subcrowded, white to very pale pinkish in mass, and up to 15 mm broad; the short gills are truncate, of varying length, adjacent to margin or stipe or neither.

The stem is 150 - 180 mm long and about 20 mm wide (more or less); white; with a copious, skirt-like white annulus; and with a large, membranous, white, sack-like volva at the base. The external surface of the 50 - 60 x 35 - 50 mm, tubular, sack-like volva is white, sometimes with pale yellowish or pale tannish tints.

The spores measure (6.5-) 9.2 - 12.5 (-16.8) x (5.8-) 8.0 - 10.8 (-12.3) µm and are subglobose to broadly ellipsoid (occasionally globose or ellipsoid) and are inamyloid. Clamps are present at bases of basidia.

Like other members of the "Slender Caesar group" (e.g., A. jacksonii Pomerleau), the present species has a substantial felted extension to inner limb of the volval sac. This limb may be carried up in its entirety by the edge of the annulus during stipe expansion, as in the drawing above (right). The "Slender Caesars" are technically called Amanita stirps Hemibapha. See Amanita hemibapha (Berk. & Broome) Sacc. for a discussion of this stirps.

In the original description of this species, the spores were incorrectly described as amyloid.

Amanita chepangiana occurs with members of the Fagaceae and Dipterocarpaceae from China and peninsular southeast Asia to Nepal.
-- R. E. Tulloss and Zhu L. Yang