Amanita species 02: The Little Brown Amanita

[ Basidiomycetes > Agaricales > Amanitaceae > Amanita . . . ]

by Michael Kuo

I find this tiny Amanita in June and July, growing in soil or moss on oak-hickory ridgetops in central Illinois. It is a tiny, brownish species with a basal bulb and a volva that adheres tightly to the bulb except for a tiny extension (a "limb," in Mycologese) at the top. Under the microscope, its spores are amyloid and nearly round.

Similar collections have been made and studied by Amanita expert Rodham Tulloss, and his "Amanita species 02," featured in his key to northeastern Amanita species as well as his 1995 treatment of West Virginia amanitas, may be the same species. Sherry Kay reports similar collections in Kansas.

Amanita solaniolens, known from Nova Scotia, is very similar but is mycorrhizal with eastern hemlock, features olive to greenish colors, and smells like "old potatoes" (Stewart & Grund, 1974). The green shades of Amanita solaniolens remind its authors of the color of Amanita phalloides, but I have seen Amanita phalloides specimens that lacked greenish hues and were better described as "brownish"; the differences between the "Little Brown Amanita" and Amanita solaniolens may not be great enough to merit separate species status.

No Amanita species should be considered for the table--and the "Little Brown Amanita" belongs to the deadly, amatoxin-containing section of the genus.

Description:

Ecology: Mycorrhizal with white oak, appearing in oak-hickory woods; often growing in moss; June and July; Coles County, Illinois.

Cap: 15-40 mm; convex becoming planoconvex; pale brown to grayish brown with a darker center; somewhat radially streaked; the margin not lined; usually without universal veil remnants but occasionally with a few whitish to grayish patches.

Gills: Free from the stem; crowded; with frequent short-gills; white.

Stem: To 60 x 7 mm; more or less equal; terminating in a small, nearly round basal bulb measuring about 10-15 x 10-15 mm; whitish; sometimes discoloring a little brownish on handling; fairly smooth; with a thin, high, white ring that flares upwards or hangs skirtlike; with an adherent white volva that extends as a limb for a few millimeters.

Flesh: White; unchanging.

Odor: Not distinctive.

Spore Print: White.

Chemical Reactions: KOH on cap surface negative.

Microscopic Features: Spores 6.5-9.5 µ; round or nearly so; smooth; amyloid.

REFERENCES: Herb. Kuo 06010403, 05310708, 07080701, 07140701, 07200704, 07270701.

Tulloss's spore measurements for his "Amanita species 02" are "(7.0-) 7.5 - 9.2 (-10.8) x (6.3-) 6.6 - 8.5 (-10.1) µ," with average Q of 1.09. Stewart & Grund's Amanita solaniolens features "globose to subglobose" spores "(6.6-) 7.2 - 9.0," with average Q of 1.0.

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Cite this page as:

Kuo, M. (2008, March). Amanita sp. 02: The little brown amanita. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/amanita_sp_02.html