Agaricus andrewii identification

About mushroom

Agaricus andrewii Freeman False Meadow Mushroom Cap 2-6cm across, convex then flattened, but with inrolled margin until fully mature; pure white, to cream when old; smooth, silky-fibrillose, margin of cap with floccose remnants of white veil. Gills free, crowded, broad; bright pink when young, then soon chocolate brown, and finally black. Stem 25-50 x 10-15mm, equal to tapered at the base; white; fibrillose to woolly below the faint evanescent ring zone. Flesh firm; white. Odor very pleasant. Taste very pleasant. Spores broadly ellipsoid, 7-8 x 4-5µ. Deposit purplish brown. Marginal cystidia sparse, prominent and turnip-shaped to club-shaped. Habitat As yet the exact distribution of this species is uncertain because of confusion with Agaricus campestris. However, it would appear to be widespread at least in eastern north America as far south as North Carolina. Season late September-November. Edible and choice, it has doubtless been mistakenly collected many times as Agaricus campestris. Comment The more familiar Agaricus campestris lacks any marginal cystidia and may not be as common in America as is usually supposed. Apart from the microscopic differences, Agaricus andrewii would appear to differ hardly at all macroscopically, except that it seems to have a more consistently smooth and purer white cap than Agaricus campestris.


Ecology: Saprobic; growing alone, gregariously, or sometimes in fairy rings, in meadows, fields, lawns, and grassy areas; late fall to early winter (occasionally in summer; sometimes year-long in California); widely distributed and common in North America.

Cap: 3-11 cm; convex to broadly convex, occasionally nearly flat; whitish; smooth and glossy to fibrous to nearly wooly or scaly.

Gills: Free from the stem; deep pink becoming brown and then dark chocolate brown in maturity; crowded; covered with a thin white partial veil when in the button stage.

Stem: 2-6 cm long; 1-2.5 cm thick; more or less equal; sometimes tapering slightly to base; with a quickly collapsing white ring; not bruising yellow.

Flesh: Thick and white throughout; not bruising yellow anywhere, even in the base of the stem; very rarely discoloring a pinkish wine color in wet weather.

Odor and Taste: Pleasant.

Chemical Reactions: Cap surface not yellowing with KOH.

Spore Print: Dark chocolate brown.

Microscopic Features: Spores: 5.5-10 x 4-7 µ; elliptical. Cheilocystidia to 10 µ wide. Universal veil hyphae (on cap surface and stem base) without inflated elements.

The North American forms of this mushroom are apparently numerous--and several closely related (identical?) species have been described, including Agaricus andrewii (cheilocystidia 11-18.5 µ wide; universal veil hyphae with inflated elements) and Agaricus solidipes (spores up to 12 µ long; cheilocystidia absent). See also Agaricus porphyrocephalus.

Agaricus andrewii photos

More info about Agaricus andrewii mushroom

Stem type:
Ring on stem
Grows on the ground
Found in fields
lawns or on roadsides
Spore colour:
Purplish to black
Cap type:
Convex to shield shaped
Fungus colour:
White to cream
Normal size:
North America
Last modification: 2015-10-16 14:29:50

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