BRIEF DESCRIPTION: Amanita praelongispora is named for its spores, which may be more than 3 times as long as they are wide.

The cap is starkly white and 40 - 90 mm wide.

The gills are white (at least once reported as pinkish), narrowly adnate or adnexed or barely free, and crowded.  The short gills are rounded-truncate to attenuate.

The exannulate stipe is somewhat stocky (50 - 80 x 6 - 12 mm) and, at first, densely floccose; at the stipe base is an abrupt to submarginate, ellipsoid to turnip-shaped bulb.  There is a thin membranous outer layer to the volva which can be found as a distinct limbate volva at the top of the stipe's basal bulb.

The mushroom has no odor.

According to Bas (1969), the very narrow spores measure 10 - 12.5 (-13.5) x 4 - 5 µm and are cylindric to bacilliform and amyloid.  Clamps are abundant at bases of basidia.  Spores from recent Florida, Mississippi, and Texas collections measure (8.7-) 9.4 - 12.3 (-16.4) x (3.5-) 3.8 - 4.9 (-5.2) µm and are dominantly cylindric (rarely elongate, infrequently bacilliform).

Amanita praelongispora is often associated with oak and pine.  The species is moderately common in the southern part of the sandy Atlantic coastal plain of the U.S.A. and along the U.S. Gulf Coast.

Bas placed this species in subsection Limbatulae Bas and in his strips Limbatula (see A. limbatula Bas). Despite its name (which I have echoed in the proposed English name for this mushroom), the spores of this species are neither the longest nor the narrowest in the Lmibatulae. -- R. E. Tulloss