Amanita cacaina - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita cacaina
name status nomen provisorum
author Tulloss
english name "Dark Chocolate Ringless Amanita"
images


  • 1. Amanita cacaina, Otter Creek Wilderness, Monongahela Nat. For., Randolph Co., West Virginia, U.S.A. (RET 201-10)



  • 2. Amanita cacaina, Otter Creek Wilderness, Monongahela Nat. For., Randolph Co., West Virginia, U.S.A. (RET 201-10)

    • intro The following text is based on original research of R.E. Tulloss.

    One oddity of this species is that the gills, cap flesh and stipe flesh all will, at least sometimes, turn pink in a sectioned button; however, this reaction has not been seen in more mature material.
    cap The dark chocolate-brown cap is 58 - 74 wide, and at first is rounded and bell-shaped before expansion; it has a rounded knob at its center.  The white flesh may have a dark gray tone under the cap's skin.  The flesh is 3 - 5 mm thick and thins evenly for more than half of its radius and then is thin to the edge.  The cap's edge is grooved.  Volval remnants are absent or can be seen as a large pale gray patch that is smooth, leathery, and can at times be perforated in places.  The patch may at times be so large that it hangs below the cap's edge.
    gills The gills are free and close, they lack a descending line on the upper stem.  The gills have a minutely powdered edge and are 5 - 6.5 mm broad. The short gills are squarely cut off or terminate with a stair-case-like edge and have a prominent long narrow tooth-like projection along the underside of the cap.
    stem The white to pale brown stem is 72 - 81 x 10.5 - 11 mm and narrows upward flaring very slightly at the top.  The surface of the stem is powdery and chalky near its top and is covered with fine hairs at its bottom.  The stem is faintly lined.  The stem's off-white flesh is stuffed to hollow, or stuffed only in its lower half.  The volval remnants are carried entirely on the cap or are seen as a sac-like dry leathery white volva that is about 1 mm thick.
    odor/taste This species is described as odorless; the taste was not recorded.
    spores The spores are 8.7 - 10.8 (-11.9) × (7.3-) 8.7 - 9.1 (-10.8) µm and are globose to subglobose to broadly ellipsoid and inamyloid.  Clamps are probably lacking from bases of basidia.
    discussion This species is found growing solitarily or in small groups.  Its known range is limited to West Virginia where it occurs (a) in association with Eastern Hemlock (Tsuga canadensis), various species of Birch (Betula), Oak (Quercus), and Maple (Acer) or in regions with Alder (Alnus) and Sphagnum bogs or in dark loam under Red Spruce (Picea rubens), Yellow Birch (Betula allegheniensis), Eastern Hemlock, and species of Rhododendron.

    The only specimens on which spores have been found, have spores that were possibly overly large because of the specimens' immaturity. —R. E. Tulloss and N. Goldman
    brief editors RET

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