Agaricus bernardii

What You Should Know

Agaricus bernardii is an edible agaric fungus in the family Agaricaceae. A short, squat mushroom, the thick stem is usually less than the diameter of the cap. Found in Asia, Europe, North America, New Zealand and Australia it is a salt-tolerant species that grows in salt marshes, dunes, and coastal grassland.

The cap surface is whitish to buff, and can develop scales or warts in age. A tough-stemmed, fairly large species that features red-staining flesh, an inrolled cap margin, and a ring that sheathes the stem and flares outward at its apex.

Gills are initially pink before turning brown when the spores mature. The flesh turns reddish when it is cut or bruised.

Other names: Salt-loving Mushroom.

Agaricus bernardii Mushroom Identification

1. Ecology

   Saprobic; growing alone, scattered, or gregariously in sand dunes and drainage areas near coastal and brackish waters; also in lawns and grassy areas along roadsides, especially where roads are salted for ice in the winter; summer and fall, or overwinter in warm climates; precise North American distribution uncertain, but well documented in California, Colorado, and Pennsylvania.

2. Cap

   5–15 cm; convex, becoming broadly convex; white and fairly bald when young, becoming cracked or subscaly and sometimes developing brownish or brown colors; dry; the margin strongly inrolled.

3. Gills

   Free from the stem; close or crowded; short-gills frequent; pink at first, becoming brown and then dark chocolate brown in maturity; covered with a white partial veil when in the button stage.

4. Stem

   5–9 cm long; 2.5–3.5 cm thick; more or less equal, or tapering to base when mature; bald or finely roughened; with a sheathing white ring that flares outward on its upper edge; solid and very firm; whitish to brownish, bruising reddish.

5. Flesh

   Whitish; changing to pinkish or reddish when sliced; not yellowing, even in the base of the stem.

6. Odor

   Unpleasant; reminiscent of brine.

7. Chemical Reactions

   KOH negative on cap surface.

8. Spore Print

   Dark brown.

9. Microscopic Features

   Spores: 6–8 x 5–6 µm; broadly ellipsoid; smooth; thick-walled; brown in KOH, with a pale, contrasting apiculus. Basidia 4-sterigmate. Cheilocystidia 30–50 x 5–10 µm; cylindric-flexuous to clavate, capitate, or a bit irregularly swollen toward the apex; septate; smooth; thick-walled; yellowish to brown in KOH. Pleurocystidia not found. Pileipellis a poorly defined cutis; elements 2.5–10 µm wide, smooth, hyaline to yellowish in KOH.

Agaricus bernardii Look-Alikes

1. Agaricus augustus

   Usually slightly larger, with a purple-brown spore pattern.

2. Agaricus benesii

   Has flesh that stains reddish when cut. It differs in that the surface of the cap turns pinkish-red when bruised, the lower part of the stem has whitish scales rather than being smooth, it grows with conifers and lacks a briny taste or odor.

3. Agaricus bitorquis

   Has a similar appearance, but can be distinguished by its double ring, and the lack of a fishy or briny odor. Additionally, A. bitorquis does not stain reddish when cut, and usually does not have a scaly or warty cap.

Agaricus bernardii Taxonomy and Etymology

Described by Lucien Quélet (often written as Quelet without an accent) in 1878 and given the scientific name Agaricus bernardi, the salty mushroom looks similar to several other species, but its red flesh (when cut) at least aids identification. The currently accepted scientific name Agaricus bernardii comes from an 1878 publication by Lucien Quélet.

The specific epithet bernardii refers to G. Bernard, the discoverer of the collection from La Rochelle, France, which Lucien Quélet used as Psaliota bernardii when preparing his original description of the species.

Agaricus bernardii Synonyms

1. Psalliota bernardii Quél., 1879

2. Pratella bernardii (Quél.) Quél., 1888

3. Fungus bernardii (Quél.) Kuntze, 1898

4. Agaricus campestris subsp. bernardii (Quél.) Konrad & Maubl., 1937

5. Agaricus robynsianus Heinem., 1957

6. Agaricus bernardiiformis Bohus, 1975

Sources:

Photo 1 - Author: Ron Pastorino (Ronpast) (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 2 - Author: Nathan Wilson (nathan) (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 3 - Author: Thomas Pruß (Creative Commons Attribution-Share Alike 3.0 Unported)