Amanita flavoconia - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita flavoconia var. flavoconia
name status nomen acceptum
author G. F. Atk.
english name "American Yellow Dust Amanita"
images
  • Amanita flavoconia, eastern Pennsylvania, U.S.A.Amanita flavoconia, eastern Pennsylvania, U.S.A.

    1. Amanita flavoconia, eastern Pennsylvania, U.S.A.


  • 2. Amanita flavoconia, 2008 COMA foray, Connecticut, U.S.A.

  • Amanita flavoconia, Franklin Co., New York, U.S.A.Amanita flavoconia, Franklin Co., New York, U.S.A.

    3. Amanita flavoconia, Franklin Co., New York, U.S.A.

    • intro The following information is derived from the original research of RET.
    cap The yellow-orange cap is 30-63 mm wide; it is most intensely orange over the center and sometimes is more yellow at the edge.  The cap appears to have darker colored radial fibers decorating it.  The color is unchanging when cut or bruised.  When the ring is beginning to separate, the cap is bell shaped.  At maturity the cap is convex to nearly planar.  The off-white flesh of the cap is 2.5-4.5 mm thick above the stem and thins evenly to the edge.  The edge of the cap is infrequently striate.  The orangish yellow volval remnants are unchanging when bruised or cut and if present are seen as thin small patches and warts distributed irregularly.  
    gills The gills are free to narrowly attached. Sometimes there are fine descending lines on the upper stem,when present a 10x lens is often necessary to see them.  The whitish gills are close to slightlycrowded and are unchanging when cut or bruised.  The gills often have yellow powder on their edges at least at first.  This can give a false impression of the color of the gill to a person looking directly at the bottom of the cap.  The plentiful short gills diminish gradually and are of diverse lengths.
    stem The stem is 45-105 x 3-11 mm and yellow either in the upper part of the stem, both the upper and lower parts except for a pale region in between, or the entire stem except for the bulb.  It is unchanging when cut or bruised, narrows upward, and barely flares at the top.  The stem is powdery above the ring and is decorated with vertical fine lines; it sometimes has raised fibers below the ring.  The white bulb measures 18-20 x 10-19 mm and has a turnip-like shape with a rounded bottom.  The stems is hollow to stuffed and its flesh is white to pale yellow especially near the top, and is infrequently pale pink in the bulb.  The membranous skirt-like ring is at the top of the stem and collapses and becomes brown with age.  The ring sometimes has yellow volval fragments on its underside.  Yellow-orange volval remnants are present as fragmented warts and patches on the lower stem and top of the bulb, they can often be left behind in the soil during collection.
    odor/taste This species is odorless, and its taste has not been recorded.
    spores The spores measure (6.5-) 6.8 - 9.0 (-10.6) × (4.8-) 5.0 - 7.0 (-8.9) µm and are broadly ellipsoid to ellipsoid (infrequently subglobose) and amyloid. Clamps are absent from bases of basidia.
    discussion Amanita flavoconia is one of the most common and wide-spread species of Amanita in eastern North America. It is one of the earliest to appear in the spring.  If Amanita flavoconia var. inquinata Tulloss, Ovrebo & Halling is included, the range extends from boreal forest to the Colombian Andes.  A. flavoconia var. flavoconia is known from forests including conifers, beech, or oak in southeastern Canada as far north as the Island of Newfoundland (boreal forest in Gros Morne Nat. Pk.) and the eastern USA as far south as eastern Texas (sandy pine-oak forest).  The species was originally described from New York state, and Atkinson's photograph of the type collection can be found here. The present species is often mistaken for Amanita frostiana (Peck) Sacc., a species with inamyloid, globose spores.  Even the type collection of A. frostiana contains some specimens of A. flavoconia.

    For comparison, see Amanita elongata Peck, A. erythrocephala Neville, Poumarat & Aste, A. flavella E.-J. Gilbert & Cleland, A. flavipes S. Imai, A. flavivolva Murrill, A. flavoconia var. inquinata (link above), A. fraterna (Murrill) Murrill, A. luteofusca Cleland & E.-J. Gilbert, A. xanthella Corner & Bas, and A. xanthomargaros Corner & Bas.

    Sometimes people report a yellow spore print for this species.  The spores in fact are white; but, if a spore print is obtained by lying the cap directly on the material being used to collect the print, yellow powder from the gill edges will make the print appear to be yellow.—R. E. Tulloss and N. Goldman
    brief editors RET

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