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Pholiota adiposa agg.

by Michael Kuo, 14 July 2024

Pholiota adiposa is a yellow slimeball that grows in clusters on downed logs, standing dead trees, and stumps—and in the case of the latter, mushroom hunters should be advised that creepy little girls might emerge from the stumps. This, anyway, is what Hillary Swank discovers in The Reaping. Hollywood offers mushroom hunters an occasional thrill: the pholiotas Swank ignores in The Reaping; honey mushrooms in Lord of the Rings; polypores in Robin Hood: Prince of Thieves and The Contract. You are truly a myco-geek when you reach for the remote to zoom in and advance the movie frame by frame in order to identify mushrooms in the background.

Defining features for the Pholiota adiposa species group include the clustered growth on deadwood, the slimy orangish to yellow caps, which feature scattered brownish to reddish brown scales—and the dry, somewhat scaly stems. Microscopic features include chrysocystidia and ellipsoid spores with a very tiny pore. As with all pholiotoid mushrooms the spore print is brown.

Attempts to separate species within Pholiota adiposa have been made for literally centuries. Morphological species that have been designated are many, including Pholiota cerifera (also known as Pholiota aurivella) and Pholiota limonella, separated on morphological differences in cheilocystidia and spores; see for example Smith & Hesler 1968, Holec 2001, or Jacobsson 2018. Biological species-based studies of mating intercompatibility have revealed the ability of several morphologically distinct species in the group to mate despite their morphological differences; see Farr et al. 1976 or Jacobsson 1987. And, most recently, a DNA-based study (Tian & Matheny 2021) found specimens from across the globe identified as adiposa, limonella, and aurivella to be the same phylogenetic species, closely related to another group of specimens which were identified as aurivella.

Given the varying results and concepts, the wisest course for the moment is probably to treat these mushrooms as an aggregate species; adiposa is the oldest name in the group (Batsch 1786).

Thanks to Cole Furman for documenting, collecting, and preserving Pholiota adiposa for study; his collection is deposited in The Herbarium of Michael Kuo.

Description:

Ecology: Saprobic and possibly parasitic; growing alone or, more commonly, in clusters on deadwood; frequently found on the wood of birch and alder, but also documented on a wide variety of hardwoods (and occasionally on the wood of conifers); summer and fall, or over winter in warm climates; originally described from Schöndorf, Germany; widespread as a species group (known from Europe, Asia, Oceania, North America, South America, and Africa). The illustrated and described collections are from Illinois, Kentucky, and Missouri.

Cap: 2.5–12 cm; convex, becoming broadly convex, broadly bell-shaped, or nearly flat; sticky or slimy when fresh; yellow to orangish yellow or brownish yellow; adorned with small, brownish to reddish brown scales that are easily wiped away and often gelatinize, disappearing or becoming indistinct by maturity; the margin not lined.

Gills: Narrowly attached to the stem; close or nearly crowded; short-gills frequent; whitish to pale yellowish when young, becoming brownish yellow to tawny brown; at first covered by a whitish, cobwebby partial veil.

Stem: 5–10 cm long; 5–10 mm thick; dry; silky near the apex; with a flimsy ring or ring zone (often indistinct); whitish to yellow under reddish brown to yellowish brown scales; base covered with whitish mycelium.

Flesh: Pale yellow; not changing when sliced.

Odor and Taste: Not distinctive.

Chemical Reactions: KOH red to orangish on cap surface.

Spore Print: Brown.

Microscopic Features: Spores 7–11 x 4–8 µm; ellipsoid, with a very tiny pore at one end; smooth; thick-walled; orangish brown in KOH. Basidia 25 x 6 µm; subclavate; 4-sterigmate. Chrysopleurocystidia often collapsed and poorly defined; 30–50 x 8–13 µm; lageniform; thin-walled; orangish golden in KOH, with refractive contents. Leptocheilocystidia 30–60 x 5–10 µm; cylindric with a clavate apex, or lageniform to subutriform; smooth; thin-walled; hyaline to orangish golden in KOH. Lamellar trama parallel. Pileipellis an ixocutis; elements 2–5 µm; wide, smooth or a little encrusted, golden yellow in KOH. Clamp connections present.

REFERENCES: (A. J. G. K. Batsch, 1786) P. Kummer, 1871. (Kauffman, 1918; Overholts, 1927; Smith & Hesler, 1968; Smith, 1975; Farr, Miller & Farr, 1976; Smith, Smith & Weber, 1979; Arora, 1986; Jacobsson, 1987; Phillips, 1991/2005; Schalkwijk-Barendsen, 1991; Lincoff, 1992; Horn, Kay & Abel, 1993; Breitenbach & Kränzlin, 1995; Holec, 1998; Barron, 1999; Noordeloos, 1999; Holec, 2001; Matsumoto et al., 2003; Roody, 2003; McNeil, 2006; Miller & Miller, 2006; Boccardo et al., 2008; Trudell & Ammirati, 2009; Gierczyk et al., 2011; Buczacki et al., 2012; da Silva et al., 2012; Kuo & Methven, 2014; Desjardin, Wood & Stevens, 2015; Siegel et al., 2015; Baroni, 2017; Gminder & Böhning, 2017; Woehrel & Light, 2017; Jacobsson, 2018; Sturgeon, 2018; Læssøe & Petersen, 2019; Lee at al., 2020; Kibby, 2021; MacKinnon & Luther, 2021; Tian & Matheny, 2021.) Herb. Kuo 10160405, 10280401, 11010501.

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Spore print

Spores

Leptocheilocystidia

Chrysopleurocystidia

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Cite this page as:

Kuo, M. (2024, July). Pholiota adiposa. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/pholiota_adiposa.html