Amanita radiata

The following description is based on Jenkins (1984).

The cap of Amanita radiata is up to 70 mm wide, plano-convex to planar, brown slightly striate margin.  The volval remnants are present as moderately thick, whitish, floccose-membranous patches in the center.  The flesh is white, 7 mm thick over the stem.

The gills are adnexed, moderately crowded, narrow, white; the short gills are moderately abundant and attenuate.

The stem is 45 - 60 × 10 -13 mm, tapering upward, slightly expanded at the top, solid, fibrillose to fibrillose-scaly, whitish with brownish fibers, with a very slight floccose-membranous rim on the bulb, breaking into patches.  The ring is apical, easily lost, white.  The basal bulb is oval, 40 × 25 mm wide.

This species has no odor or taste.

The spores measure 8.6 - 10.2 × 3.9 - 5.5 µm and are elongate to cylindric and amyloid.  Clamps are absent at bases of basidia.

Originally described from Alabama, USA under Loblolly Pine.

In his discussion of this species, Jenkins (1984) says that he had difficulty placing it to section in the genus Amanita because the pigmented cap is reminiscent of caps in section Validae whereas the narrow spores and easily lost ring are characters he associated with section Lepidella.  Amanita media Dav. T. Jenkins is another species which he found difficult to place for the same reasons.  Based on recent molecular studies, it appears that section Validae has ancestors that fall outside section Lepidella in the current taxonomic scheme of Amanita.  This suggests that any group of ancestors of a species in section Validae will probably include ancestors in Lepidella but must include younger ancestors that we would recognize today as belonging in a different section.  As molecular studies advance, this view may change; however, at the moment, perhaps it is wise to seek further with regard to arguments for sectional placements for so-called "borderline" species.  For example, in the present case the fact that the subhymenium is not cellular in A. radiata could argue against placement in section Validae.  When I had trouble deciding on placement of A. salmonescens Tulloss, Dr. Bas advised me that the cellular hymenium could be a factor supporting placement in section Validae.  Obviously, further work on the three taxa named in these notes is necessary.—R. E. Tulloss

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