Amanita radiata - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita radiata
name status nomen acceptum
author Dav. T. Jenkins
english name "Brown Fence-Sitting Amanita"
images


  • 1. Amanita radiata, virgate cap with striate margin, Ocala Nat. For., Marion Co., Florida, U.S.A. (RET 548-1).


  • 2. Amanita radiata, Ocala Nat. For., Marion Co., Florida, U.S.A. (RET 548-1).



  • 3. Amanita radiata, very thin and fragile veil, Ocala Nat. For., Marion Co., Florida, U.S.A. (RET 548-1).



  • 4. Amanita radiata, attenuate lamellulae of diverse lengths, Ocala Nat. For., Marion Co., Florida, U.S.A. (RET 548-1).

    • intro

    The following description is based on Jenkins (1984).

    cap

    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.

    gills

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

    stem

    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.

    odor/taste

    This species has no odor or taste.

    spores

    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.

    discussion

    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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