Agrocybe pediades

[ Basidiomycota > Agaricales > Strophariaceae > Agrocybe . . . ]

by Michael Kuo

This cosmopolitan mushroom appears in grassy areas (lawns, pastures, meadows), and features a thin, yellow-brown cap, a skinny stem that lacks a ring, and a medium brown spore print. Several grass-loving mushrooms are similar, including Panaeolus foenisecii, with a pointier, darker brown cap that fades and becomes two-toned, and Agrocybe dura, which is a bit larger and features a white cap that can become yellowish with age.

Agrocybe pediades has a partial veil, but it is so ephemeral that you will need to be looking at buttons the size of pencil erasers to see it. Within a few hours, all evidence of the veil has usually disappeared.

Collections I have made in California, Colorado, and Illinois have demonstrated a color change to red or pink when a drop of KOH is applied to the cap surface; other Agrocybe species I have tested show no color change or a change to dull yellow.

Agrocybe semiorbicularis is a synonym.

Description:

Ecology: Saprobic; growing alone or gregariously in lawns, meadows, and other grassy areas (also sometimes on woodchips, manure, or compost); summer, or nearly year-round in warm climates; originally described from Europe; common and widely distributed in North America; also found in the Caribbean, South America, Asia, and Oceania. The illustrated and described collections are from California, Colorado, and Illinois.

Cap: 1–3 cm across; convex, becoming broadly convex or nearly flat; bald; sometimes sticky when fresh; dark honey yellow, fading to pale brownish yellow; often with a thin strip of white partial veil remnants on the margin when very young.

Gills: Narrowly attached to the stem; close or nearly distant; short-gills frequent; pale yellow brown becoming darker brown; when young covered by an ephemeral white partial veil.

Stem: 2–8 cm long; 2–4 mm thick; more or less equal; bald or finely fibrillose; colored like the cap; sometimes twisted; basal mycelium white.

Flesh: Whitish; not changing when sliced; thin.

Odor and Taste: Odor not distinctive, or mealy; taste usually mealy.

Chemical Reactions: KOH on cap surface red to pink.

Spore Print: Dull brown with a hint of cinnamon.

Microscopic Features: Spores 10–18 x 7–10 µm; ellipsoid, with one end flattened for a 2 µm pore; smooth; golden brown in KOH; brown in Melzer's reagent. Basidia 25–30 x 8–10 µm; subclavate; 4-sterigmate. Pleurocystidia usually absent; when present scattered and rare; to 30 x 10 µm; lageniform, sometimes with a slight apical knob of encrusting material; smooth; hyaline in KOH. Cheilocystidia 30–50 x 7–14 µm; lageniform, sometimes with a subcapitate or capitate apex; thin-walled; smooth; hyaline in KOH. Pileipellis hymeniform; usually gelatinized; golden brown in KOH; terminal cells 20–30 x 5–10 µm, clavate to pyriform.

REFERENCES: (Fries, 1821) Fayod, 1889. (Smith, Smith & Weber, 1979; Phillips, 1981; Watling, 1982; Arora, 1986; Phillips, 1991/2005; Lincoff, 1992; Roody, 2003; Nauta, 2005; McNeil, 2006; Miller & Miller, 2006; Trudell & Ammirati, 2009; Malysheva et al., 2011; Buczacki et al., 2012; Kuo & Methven, 2014; Desjardin, Wood & Stevens, 2015; Siegel & Schwarz, 2016; Ryman, 2018; Læssøe & Petersen, 2019; Calaça et al., 2020; Niveiro et al., 2020.) Herb. Kuo 05039602, 06120201, 01030520, 08060501, 05020601, 05120607.

This site contains no information about the edibility or toxicity of mushrooms.

KOH

Spore print

Spores

Cheilocystidia

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Cite this page as:

Kuo, M. (2020, October). Agrocybe pediades. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/agrocybe_pediades.html