Horse mushroom or Egghead mottlegill

The cap is 6-20 cm across; in young mushrooms it's firmly hemispherical to egg-shaped, often with the margin rolled under, later becoming convex to flat. The colour is pure white to cream, with subtle yellowish tints in old mushrooms; it stains yellow to ochre when touched. The surface is smooth, slightly sticky in wet weather, dry and matte in dry weather, sometimes with fine fibrous scales in the centre.

The cap is 2 to 6 cm across, sometimes up to 9 cm. It's egg-shaped when young, then like half an egg or a blunt cone, only rarely convex. The margin isn't lined; it overhangs the gills and sometimes carries scraps of veil.

It's whitish, cream or pale clay-coloured, darker in the centre, and fades with age. When wet it's sticky; when dry it's smooth and shiny, often wrinkled or cracked.

The gills are free and crowded, greyish-white with a pinkish tinge when young, becoming dark brown to chocolate-blackish with age. The spore print is dark brown.

The gills are attached, crowded and broad. They start off whitish or greyish, become mottled with black patches and end up black, with whitish edges.

The spore print is black.

The stem is 6-12 cm tall and 1.5-3 cm thick, stout, fleshy and cylindrical, slightly thickened at the base, and white to cream. Near the top is a large membranous double ring with a characteristic "toothed" lower edge (like a cogwheel), a key feature of the species.

The stem is 6 to 15 cm tall and 3 to 10 mm thick, long and slender compared with the cap, whitish or cap-coloured, paler and finely powdery at the top, slightly swollen at the base, brittle and hollow.

Above the middle there's a thin white ring that turns black on top from spores. It's fragile and can fall off, so look for it on young specimens.

The flesh is firm, meaty and white; when cut, it slowly yellows in the cap and upper stem. It does not redden (unlike A. silvaticus). The smell is distinctly anise-almond, a characteristic feature of the species.

The flesh is thin, soft and whitish, pale yellowish and brittle in the stem, and doesn't change colour when cut.

Distinctly anise-almond and fruity, and this is the most telling feature. Rub the flesh between your fingers to bring it out. It's one of the most pleasant smells you'll come across while foraging.

The smell is indistinct.