Amanita mobilimanica - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita mobilimanica
name status nomen provisorum
author Tulloss
english name "Loose Sleeve Ringless Amanita"
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  • Amanita mobilimanica, Chiricahua Mtns., Cochise Co., Arizona, U.S.A.Amanita mobilimanica, Chiricahua Mtns., Cochise Co., Arizona, U.S.A.

    1. Amanita mobilimanica, Chiricahua Mtns., Cochise Co., Arizona, U.S.A.

    • intro Of the species of Amanita section Vaginatae known from the Chiricahua Mountains of southeastern Arizona, this species alone has a volval limb which regularly separates from its cup-like base and is pulled up the stem (away from the cup-like base) during expansion of the fruiting body. Although, this character is very distinctive in the field in the Chiricahuas, it cannot be trusted as a descriminating character in comparison to other species of the section around the world.  In the latter case, microscopy cannot be avoided.
    cap The cap of A. mobilimanica is 37 - 86 mm wide.  Cap color ranges from pale sepia to sepia-brown to dark brown with a darker disc or sepia-gray with sepia disc or lead gray or pale gray to gray (with or without a darker disc).  Sometimes the cap is very pallid at first and becomes more distinctly pigmented with age; sometimes it is faintly virgate.  The cap's shape is hemispheric to convex to planoconvex, usually with a distinct umbo in larger specimens.  The cap surface may be tacky or dry and matt to subshiny to waxy.  The cap's flesh is gray or brownish gray just under the cap's skin, in a band up to 1 mm thick across theentire pileus or only in the region of the umbo; otherwise, the flesh is white, watery sordid white when crushed, and occasionally ochraceous around the edges of old wounds.  The cap's margin is striate, with striations occupying from 20% to one-half of the cap's radius.  Volval remnants are usually absent. Occasionally volval remains are present as a small or large patch or patches; these are membranous, originally white, eventually pale gray, sometimes wrinkled, usually smooth, and usually easily removed.
    gills The gills are free to receding to (occasionally) narrowly adnate with a decurrent tooth or (occasionally) a rather long (although faint) decurrent line on the upper stem (use hand lens).  They are close to subcrowded to crowded, off-white to sordid cream to cream to pale yellowish cream in mass, sordid cream to pale sordid cream to pale cream to very pale off-white to very pale grayish white to white in side view, unchanging when cut or bruised, although sometimes becoming sordid with age.  Short gills are truncate to subtruncate to excavate-truncate, common to plentiful, of diverse lengths, unevenly distributed (sometimes infrequent in some sectors), and occasionally attached to the stem rather than to the cap's margin.
    stem The ringless stem of this mushroom is 59 - 133 × 5.5 - 15 (-38) mm, white to very pale off-white, becoming pale gray to gray to brownish gray from handling, narrowing upward or cylindric, only flaring very close to the very top of the stem (if at all), faintly punctate (use hand lens) or faintly frosty or chalky near the top, with fibrils on lower stem white to gray to dark gray.  The stem's flesh is very pale grayish white or off-white to white with pale watery lines to white, unchanging when cut or bruised, hollow or (occasionally) partially stuffed to stuffed.  The volva is sack-like, 25 - 80 × 7± - 24 mm, membranous, soft, somewhat easily torn, white to pale off-white, and becoming very pale gray to pale brownish gray to gray in uppermost part of the sack.  At first, the sack flares outward in its upper portion, then it collapses on the stem.  The sack is often constricted or broken above a cup-like piece that encloses the stem's base.  The separate portion is raised along the stem like a loose sleeve.  The strangulate or exposed-stem region has been observed to be 0 - 24 mm long.
    odor/taste The odor is indistinct or faintly earthy.  The taste is not recorded.
    spores The spores measure (7.7-) 9.2 - 11.8 (-15.0) × (6.1-) 8.4 - 10.5 (-14.0) µm, are globose to subglobose (infrequently broad ellipsoid), and inamyloid.  Clamps are lacking at the bases of basidia.
    discussion —R. E. Tulloss
    brief editors RET

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