An Illustrated Guide to ARIZONA WEEDS

The University of Arizona Press

FLY MUSHROOM, fly amanita, fly agaric



MUSHROOM FRUITING BODIES-The familiar mushroom, consisting of a stalk and an umbrellalike cap, is the fruiting body of these fungus plants. These arise at irregular intervals from the buried vegetative parts, usually after prolonged periods of summer rainfall. On the upper part of the stalk is the ring, the remains of an early veil that extended from the cap to the stalk and later ruptured, leaving a remnant on the stalk.

FLY MUSHROOM-Amanita muscaria L.

DESCRIPTION-The colorful fruiting body of fly mushroom is very conspicuous. The mature cap varies in color from brilliant scarlet to dark red, reddish-orange to orange, or yellow-orange to pale yellow, and in width from 2 1/2 to 10 inches. The upper surface of the cap is covered with many wartlike patches; white at first, yellowish-brown in age. Both the gills and spores (in mass) are white. The whitish stalk, faintly yellow in age, is 4 to 8 inches high, with a bulbous base. The large, deflexed, whitish ring may be lost in age.

DISTRIBUTION-Fly mushroom is found in woods throughout the holarctic. In Arizona it is common in the mountains along the tree margins of meadows or forest openings. It lives in the soil humus, and becomes attached to the outside of rootless of certain forest trees, forming mycorrhizae. Mycorrhizal relationships may be established with pine, spruce, fir, and aspen. Like greenspored mushroom, the fruiting bodies are most common from August to October, and sometimes form "fairy rings."

POISONOUS PROPERTIES-After the fly mushroom was eaten, the following symptoms have been known to occur: The nervous system is seriously affected. Retching, vomiting, excessive salivation, watery diarrhea, perspiration, and hallucinations usually appear within 1/2 to 3 hours. Sometimes death follows through respiratory failure, preceded by delirium and convulsions. Cattle may be poisoned by fly mushroom, but no losses, either of human or livestock, are known in Arizona.

The most deadly poisonous mushrooms known belong to the genus Amanita. Most species are distinguished by the remnants of an outer enveloping veil, or volva, found around the base of the stem and in patches on top of the cap. The volva at the stem base may form a baglike cup (death cup); or a narrow rim above a bulbous base; or a series of scaly circles on the stem above a bulbous base, as in fly mushroom. Characteristically, the ring on the upper part of the stem hangs like a short skirt.

Copyright (c) 1972 The Arizona Board of Regents

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