Major Groups > Gilled Mushrooms > Pale-Spored > Omphalinoid > Gerronema strombodes


Gerronema strombodes

[ Basidiomycetes > Agaricales > Marasmiaceae > Gerronema . . . ]

Taxonomy in Transition: ...  > Agaricales > ?-aceae > Hydropoid Clade ...

by Michael Kuo

This odd mushroom threw me for a loop several times this year. It appeared on hardwood logs in abundance in late spring and early summer throughout my main collecting areas in central Illinois. The first problem was, I had never seen it before, in over a decade of rigorous collecting. How could a mushroom suddenly appear in great numbers when it had been absent until now?

The second problem was that my collections differed so much that it took me forever to realize I was collecting one species. My first collection of the species represented very mature specimens; they were quite large (up to 10 cm across) and had yellow caps with radiating brownish fibers. Then I collected the species when it was young; these caps were grayish brown and only reached 5 cm across. It was only after I began to find the mushroom in intermediate stages that I realized the brown fibers on mature caps were the result of the cap's expansion; as it grows the densely-packed, innate brown fibers are stretched out and the yellow color underneath them begins to dominate.

Once I figured out I was looking at one mushroom, the last problem was: what on earth was it? I had no luck at all using keys in field guides and technical literature, other than to place the mushroom in what used to be called the Tricholomataceae, probably among the various genera constellated around Omphalina in its former, wider (and always disputed) sense. Eventually I resorted to a method I always argue against: I flipped through pictures of every white-spored, vaguely similar mushroom in every field guide I own. The only thing similar, once microscopic features were considered, was Gerronema strombodes, which I found only in Roger Phillips's Mushrooms of North America.

Finding a more technical treatment of the species, however, turned out to be a nightmare. After months of searching references and cross-references I finally obtained Rolf Singer's 1964 description, the authoritative source for the species. But when I eagerly sat down to read it, it began like this:

    Hut grauweiß, grau, graubraun . . .

Spanish I can handle. Italian, French, Latin . . . anything but German. Singer's key to Gerronema was easy enough to figure out, since it involves spore measurements and the like, clearly recognizeable in any language--though my reading of the key is based on the assumption that what a German-English dictionary renders as "buckles" refers to clamp connections. But the lengthy species description of Gerronema strombodes was another story, and the reader should be warned that my description of the mushroom, below, is based on Phillips's brief field-guide description and a translation of Singer's description accomplished by me and my buddy Randy Beebe during a Monday Night Football game in which Randy's German wife Christiane Eydt was repeatedly telephoned during commercial breaks.


Ecology: Saprobic on the dead wood of hardwoods and conifers; growing alone, gregariously or, most typically, in clusters; late spring through fall; apparently limited to the southeastern United States, from Ohio to Florida, west to Illinois; apparently rare.

Cap: 2.5-10 cm across; planoconvex at first, becoming centrally depressed or shallowly vase-shaped; tacky; with innate, brown to grayish brown pressed-down fibers that uniformly cover the surface when young, but begin to be stretched out and streaked-looking with age, exposing a pale yellowish surface underneath; margin becoming wavy with age.

Gills: Running down the stem; distant; yellowish white to pale yellow; short-gills frequent.

Stem: Up to 6 cm long and 8 mm thick; more or less equal; dry; minutely hairy; whitish, yellowish, or pale grayish.

Flesh: Thin; whitish to yellowish.

Odor and Taste: Taste mild or somewhat bitter; odor mild or faintly sweetish.

Chemical Reactions: KOH on cap surface negative.

Spore Print: White.

Microscopic Features: Spores 7.5-9 x 4-5 µ; smooth; elliptical; inamyloid. Basidia mostly 4-spored; 30-55 x 6-8 µ. Cystidia absent. Clamp connections present. Tissues in cap and stem sarcodimitic.

REFERENCES: (Berkeley & Montagne, 1856) Singer, 1961. (Saccardo, 1887; Singer, 1964; Moser, 1983; Phillips, 1991/2005; Norvell, Redhead & Ammirati, 1994.) Herb. Kuo 05250403, 05280407, 08160603, 07110801.

Chrysomphalina strombodes is a former name, as are Omphalia strombodes and Clitocybe strombodes.

See the page for the Hydropoid Clade to see what mushrooms DNA studies have revealed to be closely related to Gerronema strombodes.

Further Online Information:

Gerronema strombodes at Roger's Mushrooms


Gerronema strombodes

Gerronema strombodes

Gerronema strombodes

Gerronema strombodes

Gerronema strombodes

Gerronema strombodes

Gerronema strombodes
Spore print

Gerronema strombodes
Cross-section of stem demonstrating sarcodimitic tissues.

© MushroomExpert.Com

Cite this page as:

Kuo, M. (2004, November). Gerronema strombodes. Retrieved from the MushroomExpert.Com Web site: