Amanita rasitabula - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita rasitabula
name status nomen provisorum
author Tulloss
english name "Blank Slate Ringless Amanita"
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  • Amanita rasitabula, Pocono Environmental Educ. Ctr., Pike Co., Pennsylvania, U.S.A.  RET 168-7Amanita rasitabula, Pocono Environmental Educ. Ctr., Pike Co., Pennsylvania, U.S.A.  RET 168-7

    1. Amanita rasitabula, Pocono Environmental Educ. Ctr., Pike Co., Pennsylvania, U.S.A.  RET 168-7

    • cap The cap of this species is 28 - 44 mm wide, pure white to off-white, unchanging when cut or bruised, dull and tacky to shiny and dry, irregularly convex with a slight depression in the center, and (with age) shallowly convex with a faint umbo.  The cap's flesh is white, unchanging when cut or bruised, and 1.5 - 3 mm thick over the stem.  The cap's margin is striate for about 20% to 50% of the cap's radius.  Remains of the volva are usually absent from the cap.
    gills The gills of this species are free to narrowly adnate, close to crowded, lack a decurrent line on the top of the stem, are cream-white in mass and white to very pale cream in side view; they are unchanging when cut or bruised, broadest at mid-length, and have an edge that is minutely flocculose and white.  The short gills are truncate, unevenly distributed, of diverse lengths, and plentiful.
    stem The ringless stem of A. rasitabula is 72 - 80+ × 4 - 5 mm, white, becoming faintly grayish from handling, subcylindric or narrowing upward, flaring (sometimes only barely) at the top of the stem, finely punctate-squamulose in its upper 20± mm, and both minutely fibrillose and longitudinally striatulate below.  The stem's flesh is white, unchanging when cut or bruised, hollow with occasional cross-walls.  Unlike some white taxa of sect. Vaginatae, this species lacks flocculose sheath around the top of the stem.  The volva on the base of the stem in in the form of a saccate volva 22± × 7± mm, whitish, not changing color when damaged or after exposure, smooth, membranous to submembranous, sometimes tearing, and attached at or above the very bottom of the stem.  The internal limb on the inside surface of the volva is unusually tall for taxa of sect. Vaginatae, thin, and has a fibrillose rather than fleshy structure.
    odor/taste In this species an odor is lacking.  Taste has not been recorded.
    spores The spores of A. rasitabula measure (8.8-) 9.0 - 11.0 (-13.0) × (7.5-) 8.0 - 10.0 (-10.3) µm, and are subglobose to broadly ellipsoid (infrequently globose) and inamyloid.  Clamps are very likely lacking from the bases of basidia.
    discussion This species usually occurs solitarily in forest containing oak (Quercus) or conifers.  It is known best from the New England states of the U.S.  At present, its estimated range extends from southeast Canada to central Mexico (edo. Tlaxcala).  This information should be "taken with a grain of salt" because the species is not thoroughly understood.—R. E. Tulloss
    brief editors RET

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