Agaricus bernardii

Agaricus bernardii, commonly called the salt-loving mushroom, is an agaric fungus in the family Agaricaceae.

Cap

(5)7-16(21) cm, globose, convex to broadly convex then spreading to slightly depressed in center, dry, whitish to buff at first, sometimes dark brownish with age, sub-smooth then typically cracked to bordered or cuticled rupturing into large scales or innate warts, cottony, brownish, often vinous flesh between the fissures, margin strongly rolled up at first, then spreading to raised, appendiculated with velar remnants.

Gills

Free, rounded near the foot, attenuated towards the pileal margin, narrow, tight, pink at the beginning, blackish-brown at the end, with slightly paler edges.

Stem

4-10(13) x 2-4(8) cm, subequal, attenuated to rarely clavate near base or bulbous, firmly radicating, very firm, full, smooth above ring, slightly fibrous below, whitish or brownish, blushing when crushed.

Partial veil

Membranous, thick, tenacious, whitish, leaving a ± median or basal ring on the stipe, sheathing or sometimes in a band, simple, thick, marked, not toothed, pendent, narrow, persistent, with upper edge often spreading and lower edge appressed.

Mycelium

Very thick, 12-30 mm, firm, white, reddening when cut, quickly in the foot.

Smell and flavor

Strong and very unpleasant odor of brine or iodine, and weakly salty or brine flavor, sometimes not very pronounced.

Spore

Dark brown to purple brown.

Basidia

Clavate to cylindrical-clavate, mostly with 4 sterigmata 2-4 µm long, 24-28 x 6.5-8 µm.

Spores

Broadly ellipsoid to ellipsoid, smooth, without distinct germ pore, with prominent hilar appendage, dark brown, (4.9)6.3-7.2(7.9) x (4.9)5.3-5.7 (6.4)µm, 6.8 x 5.5µm average.

Cheilocystidia

forming a sterile lamellar ridge
cylindrical-elongated, convoluted, flexuous, 45-60 x 9.5-16.5 µm.

Mode of growth

solitary, scattered, or densely gregarious, often in large circles.

Ecology

Saprotrophic on sandy, disturbed soil, lawns, drained areas or in various coastal or salt meadow habitats, sometimes buried or partly emergent.

Period

June to october.

Frequency

Very rare.

Edibility

Excellent edible although its flavor can be pickled.

Chemical reactions

Negative to KOH on the cap

Remarks

This agaric is characterized by its stocky stature, its enveloping ring, its firm flesh, staining reddish when cut, its odor of brine, its dark brown spores, its convoluted cylindrical cheilocystidia and its growth in sandy, disturbed, grassy or salty.
It is a halophile species.
A. bitorquis differs by its smaller, smooth cap, its pleasant, aniseed smell, its flesh reddening slowly and slightly at the base of the stem at the cup and its growth on compact soil, along roads or urban paths.
Both species are thought to be found mostly in salt-rich places.
A. crocodilinus, similar when its pilar warts are well developed, has much larger spores, 8.5-12.5 x 5-7 µm, and a yellow KOH reaction.