Amanita muscaria

Fly agaric

About plant names...

Why would a mushroom be named “fly agaric”? I couldn’t find a clear answer to this, but “fly” could refer to its historical use as a fly killer, since it contains ibotenic acid. Or it could refer to the delirium it induces if eaten. “Agaric” roughly translates to “mushroom”—it refers to a fungal fruiting body that has a cap that is clearly differentiated from the stalk, with gills on the underside of the cap. In any case, amanitas are attractive, common, and dangerous. Amanitas are the iconic toadstool, or poisonous mushroom.

Identification: Caps are bright red in western varieties, orange or yellow in northern and eastern locales; with white, warty spots. They reach 1¾-12" (5-30 cm) in diameter, and can reach 12" (30 cm) in height. There are many varieties of amanitas—for a detailed key, see Michael Kuo’s at mushroomexpert.com.

Edibility: Poisonous This species is not as poisonous as several of its relatives, and fatalities from eating them are rare, but they nevertheless cause a wide range of unpredictable symptoms. From Wikipedia:

... Depending on habitat and the amount ingested per body weight, effects can range from nausea and twitching to drowsiness, cholinergic crisis-like effects (low blood pressure, sweating and salivation), auditory and visual distortions, mood changes, euphoria, relaxation, ataxia, and loss of equilibrium.

That’s if the effects are mild. Seizures, coma, and possibly death can occur with stronger doses. The effects of a given dose vary enormously from person to person. There is no antidote. Despite the risks, many earlier peoples have consumed it for its psychoactive effects, a practice that continues to a limited extent even today.

Amanita muscaria lacks significant amounts of amatoxins and phallotoxins, which make some of the other amanitas so deadly. But they contain a chemical cocktail I wouldn’t mess with:

• Muscarine causes “profuse perspiration, salivation, tears, blurred vision, abdominal cramps, watery diarrhea, constriction of pupils, drop in blood pressure, [and] slow pulse.”^[1]
• Muscimol causes dizziness, lack of coordination, delusions, staggering, delirium, dissociative hallucinations, muscular cramps, and hyperactivity.
• Ibotenic acid is a neurotoxin when injected. It does not appear to be directly toxic when ingested, but it acts as a “prodrug,” enabling the activation of the muscimol.

Online References:

Amanita muscaria on Mykoweb.com: the Fungi of California

Amanita muscaria on Tom Volk's Fungi site, at the Department of Biology at the University of Wisconsin

Amanita muscaria on Michael Kuo's MushroomExpert.com

Amanita muscaria on Wikipedia

Amanita muscaria on RogersMushrooms.com

References:

Turner, Nancy J.; von Aderkas, Patrick, The North American Guide to Common Poisonous Plants and Mushrooms: How to Identify More than 300 Toxic Plants and Mushrooms Found in Homes, Gardens, and Open Spaces, Timber Press, 2009, p. 79

6/2/2016 · Townsend Wildlife Management Are, Townsend, Mass­a­chu­setts

9/18/2017 · Purgatory Falls, Mont Vernon, New Hamp­shire
≈ 6 × 7" (15 × 18 cm)

9/25/2011 · Nashua River Rail Trail, Groton Center, Groton, Mass­a­chu­setts
≈ 4½ × 4½" (11 × 11 cm)

7/23/2021 · Bradbury Mountain State Park, Pownal, Maine
≈ 5 × 7" (13 × 17 cm)

9/18/2017 · Purgatory Falls, Mont Vernon, New Hamp­shire
≈ 8 × 5" (20 × 13 cm)

10/16/2011 · Nashua River Rail Trail, Groton Center, Groton, Mass­a­chu­setts
≈ 4 × 5" (10 × 12 cm) ID is uncertain

7/28/2017 · Porcupine Trail, Beaver Brook Conservation Area, Hollis, New Hamp­shire
≈ 3½ × 4" (9.3 × 10 cm) ID is uncertain

8/19/2004 · Haleakula, Maui, Hawaii ID is uncertain

9/29/2013 · North Bubble Hike, Acadia National Park, Bar Harbor, Maine
≈ 5 × 5" (13 × 12 cm) ID is uncertain

9/18/2017 · Purgatory Falls, Mont Vernon, New Hamp­shire
≈ 6 × 8" (16 × 20 cm)

9/18/2017 · Purgatory Falls, Mont Vernon, New Hamp­shire
≈ 10 × 8" (24 × 19 cm)

¹From The North American Guide to Common Poisonous Plants and Mushrooms; see reference above

Amanita muscaria description by Thomas H. Kent, last updated 14 Aug 2021.

© FloraFinder.org. All rights reserved.

7/19/2009 · Mt. Monadnock, New Hamp­shire
≈ 1½ × 1¼" (4 × 3.5 cm) ID is uncertain

10/16/2011 · Nashua River Rail Trail, Groton Center, Groton, Mass­a­chu­setts
≈ 5 × 6" (13 × 14 cm) ID is uncertain

9/25/2011 · Nashua River Rail Trail, Groton Center, Groton, Mass­a­chu­setts
≈ 7 × 4" (17 × 10 cm)

7/19/2020 · Heath Trail, Cathance River Nature Preserve, Highland Green, Topsham, Maine
≈ 3½ × 4" (8.7 × 10 cm)

7/28/2017 · Porcupine Trail, Beaver Brook Conservation Area, Hollis, New Hamp­shire
≈ 4 × 4½" (10 × 12 cm) ID is uncertain

9/18/2017 · Purgatory Falls, Mont Vernon, New Hamp­shire
≈ 8 × 9" (19 × 22 cm)

7/28/2017 · Porcupine Trail, Beaver Brook Conservation Area, Hollis, New Hamp­shire
≈ 4 × 4½" (10 × 11 cm) ID is uncertain

8/24/2018 · Old Long Loop, Beaver Brook Conservation Area, Hollis, New Hamp­shire
≈ 1½ × 1¼" (4.3 × 3.5 cm)

7/15/2020 · Cathance River Nature Preserve Trails, Highland Green, Topsham, Maine
≈ 4 × 5" (10 × 12 cm)

9/26/2011 · Pearl Hill State Park, Townsend, Mass­a­chu­setts
≈ 3 × 4" (7.9 × 9.9 cm) ID is uncertain

9/18/2017 · Purgatory Falls, Mont Vernon, New Hamp­shire
≈ 3 × 3½" (7.6 × 9.4 cm)

6/10/2016 · Monhegan Island, Maine

10/10/2016 · Old Meetinghouse Park Trails, Townsend, Mass­a­chu­setts
≈ 4½ × 5" (12 × 13 cm)

9/26/2011 · Pearl Hill State Park, Townsend, Mass­a­chu­setts
≈ 3½ × 4" (9.7 × 10 cm) ID is uncertain

9/18/2017 · Purgatory Falls, Mont Vernon, New Hamp­shire
≈ 8 × 8" (20 × 19 cm)