How to tell Field mushroom from Deadly fibrecap

The cap is 3-10 cm across, hemispherical to convex in young mushrooms, with a broad umbo in the center; it opens out with age. The surface is silky-shiny, with fine radial fibers and flattened scales. At first the color is whitish, cream or ivory; with age and when touched it slowly turns red — first pinkish, then brick-carmine or cinnamon-red. The reddening is most visible along the cap margin and wherever the mushroom is damaged. This is the key diagnostic feature.

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.

Gilled hymenophore. The gills are fairly crowded, notched where they meet the stem. In young mushrooms they are whitish-pinkish, with age olive-brown to brick-brown. The spore print is olive-brown or tobacco-colored — typical of the whole genus Inocybe.

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 stem is 3-10 cm tall and 0.5-1.5 cm thick, cylindrical or slightly widening toward the base. It's whitish to cream, with a pink or reddish-brick tinge (especially in the lower part). When touched and with age it turns red, just like the cap. The surface is lengthwise-fibrous, with no ring. The flesh of the stem is firm.

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 flesh is thick and white; when cut, it slowly turns red (not right away: sometimes only after 30 minutes or more), especially in the lower part of the stem. This is an important way to tell it from most Agaricus mushrooms, whose flesh either doesn't change color or turns yellow (though some wood mushrooms, such as Agaricus silvaticus, also redden, so check the gills and spore print too). The smell and taste of the fresh flesh are pleasant, fruity and sweetish — which is exactly what makes it so treacherous.

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.

Sweet and fruity, with notes of ripe pears or apples — unusual for the genus Inocybe, which usually smells spermatic or musty. This appealing aroma + a reddening white cap + the season when edible white mushrooms are being picked = the perfect trap for a beginner forager. Never rely on smell when identifying this species.

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.