How to tell Macro mushroom from Yellow stainer

Cap 5-15 cm across; in young mushrooms firmly hemispherical to squared-off (a characteristic feature — the "square" young cap), later becoming convex to flat. Color white to cream, sometimes grayish-brown in the center. The most characteristic sign — touching the cap or its margin leaves bright chrome-yellow spots, especially noticeable in young mushrooms. The surface is smooth, slightly sticky in wet weather.

The cap of the macro mushroom is very large — from 8 to 20, and in mature specimens up to 30–40 centimeters in diameter. When young it is almost spherical, with a thick, inrolled margin; with age it opens out to convex and flat. The surface is white or cream, dry; smooth in young mushrooms, but with age it cracks into coarse, plate-like scales reminiscent of crocodile skin. It slowly turns yellow when touched.

Gilled hymenophore — gills free, crowded. When young — pale pinkish-gray, becoming with age dark brown, chocolate-blackish. Spore print dark brown. The gill color is typical of Agaricus — it doesn't help tell the yellow stainer apart.

The hymenophore is gilled. The gills are free and very crowded. Their color changes with age: in young mushrooms they are pale pink or grayish pink, then darken to chocolate brown and blackish brown. The spore print is dark brown; the spores are noticeably large, which is exactly what the common name refers to. The pinkish young gills set this Agaricus apart from the white-gilled poisonous amanitas.

Stem 5-12 cm tall, 1-2 cm thick, cylindrical, with a pronounced bulbous base (a difference from other Agaricus species, whose stems are more even). Color white. The most important diagnostic sign: when cut, the flesh at the base of the stem and in the bulb is bright chrome yellow, often almost neon, and the reaction is fast (10-30 seconds). On the upper part — a white membranous ring, distinct in young mushrooms.

The stem is massive, thick, firm and white, 5 to 12 centimeters tall, often shorter than the cap is wide, with a thickened base. In the upper part there is a large, firm, whitish ring. The stem may turn yellow when touched. There is no volva at the base — an important difference from the poisonous amanitas.

Flesh firm, white in the cap and upper stem, bright yellow at the base of the stem even when undamaged. When cut, THE BASE OF THE STEM TURNS BRIGHT CHROME YELLOW — the main diagnostic sign. The cap yellows too, but more weakly. The smell is distinct and unpleasant — ink, phenol, medicinal ointment, creosote.

The flesh is white, thick and firm; when cut, it slowly turns yellow or pinkish, especially at the base of the stem. The taste is mild and pleasant, with a nutty note. It has a distinct aniseed-almond scent that lingers even during cooking. Because even young mushrooms tend to be wormy, check them carefully.

Distinct and unpleasant, with notes of ink, phenol, medicinal ointment, creosote, printer's ink. It comes out when you rub the flesh between your fingers, especially at the base of the stem. This smell is the most reliable sign: no edible Agaricus smells like this.

The smell is strong and pleasant, aniseed-almond — one of the defining features of the species. If, however, the mushroom smells of ink or carbolic and the stem base turns bright yellow, it is the poisonous yellow stainer, and you must not take it.