Amanita onusta - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita onusta
name status nomen acceptum
author (Howe) Sacc.
english name "Gunpowder Lepidella"
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  • Amanita onusta (Howe) Sacc.Amanita onusta (Howe) Sacc.

    1. Amanita onusta, ca. Roosevelt, Monomouth Co., New Jersey, U.S.A.


  • 2. Amanita onusta, Tennessee, U.S.A.


  • 3. Amanita onusta, Etra Lake Twp. Pk., East Windsor, Mercer County, New Jersey, U.S.A.   (RET 087-7)


  • 4. Amanita onusta, Connecticut College Campus, New London Co., Connecticut, U.S.A.   (RET 703-5)

    • cap Amanita onusta usually has a rather small cap (13 - 76 mm wide), but its cap may be more than 100 mm wide on occasion.  It is often densely covered by brownish gray volval warts.
    gills The gills of this species are white at first and soon become yellowish and appear waterlogged.
    stem Its stipe (rarely up to 150 × 15 mm including the basal bulb) is whitish and often decorated with brownish gray powdery.  The partial veil is friable and soon lost.  The bulb at the stipe base is narrow and root-like and sometimes strongly sinuous.  Brownish gray volval warts are often densely placed at the top of the stipe's basal bulb.  Sometimes, recurved scales with powdery universal veil on their tips replace the closely packed warts on the bulb in whole or in part.
    spores The spores measure (7.0-) 8.0 - 11.0 (-13.0) × (5.0-) 5.5 - 7.0 (-8.3) µm and are broadly ellipsoid to ellipsoid to elongate (rarely subglobose or cylindric) and amyloid.  Clamps are present at bases of basidia.
    discussion This species is often associated with oak or pine.

    It is a member of Bas' stirps Microlepis.  Perhaps the most similar species is A. costaricensis Tulloss, Halling, G. M. Muell. & Singer nom. prov. of Costa Rica.

    Another similar species is A. atkinsoniana Coker.  The latter has warts developing a distinct brownish to chestnut tint.  On the cap of A. atkinsoniana, the warts are significantly shorter (use 10x lens) than those of A. onusta (Bas, 1969) and farther apart.  On the bulb of A. atkinsoniana, the warts appear in many parallel rows and don't usually produce the recurved scales often seen on the upper bulb in A. onusta

    Amanita onusta is a species of eastern North America; its range extends from Quebec south and west to at least Arkansas and Missouri (per Jay Justice).  It infrequently occurs as far south as eastern Texas or the Gulf Coast states; David P. Lewis reports he has not seen it in this region since about 1982.  The species can be very common locally, at least in the northeastern U.S.

    "Deep south" collections of A. onusta (well photographed, well-documented, and well-dried) are solicited by RET.—R. E. Tulloss
    brief editors RET

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