Pavement mushroom or Agaricus subperonatus

Cap 5-15 cm across, in young mushrooms compactly hemispherical to flat-convex, the edge often inrolled. Color white to cream, sometimes with a pale brownish tint in the center. Surface smooth, slightly sticky in wet weather. Often with a partial veil at the edge when young: a thin membranous fringe.

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.

Gilled hymenophore: gills free, crowded. When young they are pale pink to bright pink, and with age they become dark brown to chocolate-blackish. Spore print dark brown.

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 3-8 cm tall, 1.5-3 cm thick, thick, meaty, cylindrical, narrowing toward the base. Color white. A distinctive double ring structure: in the upper part of the stem there are two membranous rings close together (hence the name bitorquis). This is the diagnostic feature of the species.

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, meaty, white; when cut it slowly turns pinkish to brownish. Pleasant mushroomy smell with a fresh note. Mild taste, similar to the store-bought mushroom.

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.

Pleasant and mushroomy, like fresh store-bought button mushrooms. It does not smell of ink or medicine (that would point to the yellow stainer).

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.