Field mushroom or Agaricus subperonatus

Cap 5–15 cm across, spherical in young mushrooms, then flat or slightly umbonate. The surface is white or slightly creamy and cracks in dry weather. Fibrous scales may appear as it matures. The margin is inrolled at first, then straight.

The cap of Agaricus subperonatus is 5 to 12 centimeters across. When young it is hemispherical, opening with age to convex and flat. The surface is covered with numerous pressed-down fibrous scales of brown to reddish-brown on a paler background, especially dense in the center. The scaly brown cap gives the mushroom a stout look.

Gills free (not reaching the stem), crowded, delicate pink at first, then bright pink, and chocolate-brown or blackish in mature mushrooms. The pink color of the gills is a key safety feature that distinguishes the field mushroom from poisonous species with white gills.

The hymenophore is gilled. The gills are free, not attached to the stem, and very crowded. Their color changes with age: in young mushrooms they are pale pink or grayish-pink, then darken to chocolate-brown and almost black. The spore print is dark brown. Pinkish young gills distinguish this mushroom from the white-gilled poisonous amanitas.

Stem 4–8 cm tall, 1–2 cm thick, cylindrical, solid, straight. White in color. A characteristic firm membranous ring in the middle of the stem. No volva.

The stem is cylindrical, fairly thick, white, 4 to 9 centimeters tall. Its defining feature is a dense ring, below which the stem is covered with bands of small brown scales that look like a pulled-on "stocking" or shoe — hence the name. When cut, the flesh may turn faintly red. There is no volva at the base.

Flesh firm, white, turns slightly pink when cut or stays unchanged. It does not turn yellow (yellowing is a sign of poisonous species). The taste is pleasant and richly mushroomy.

The flesh is white, fairly dense, and when cut slowly turns red or brown, especially at the base of the stem. The taste is mild, pleasant and mushroomy, typical of cultivated button mushrooms. Reddening (rather than bright yellowing) is a useful feature that distinguishes this species from the poisonous yellow stainer.

Smell pronounced, anise-almond with mushroomy notes. This is one of the most aromatic wild mushrooms. With cooking the aroma intensifies and can dominate the dish.

The smell is pleasant and mushroomy, with no sharp notes. If, however, the mushroom smells of ink or carbolic, and the flesh turns bright yellow when cut, it is the poisonous yellow stainer, and you must not take it.