How to tell White dapperling from Stinking dapperling

The cap is 4-10 cm across, hemispherical to convex when young, later flattening out with a small bump in the centre. It's white to cream, sometimes with pale ochre or cream scales in the centre, and smooth and silky white when young. The cap skin is finely fibrous or covered with small, flattened scales. The margin is thin and inrolled when young.

The cap is 1.5–5 cm across, occasionally up to 6. Young caps are bell-shaped or bluntly conical, then convex, later flattening, often with a low central bump. The surface is dry, not sticky.

The background is white or cream. The tawny, orange-brown or reddish-brown skin breaks up into small scales as the cap expands. They lie in concentric rings and thin out towards the edge. The centre stays a solid, smooth dark patch, and this 'eye' on a pale cap is usually the first thing you notice. The margin is sometimes finely lined.

The gills are crowded, thin and free (not attached to the stem). They're white to cream in young mushrooms and turn creamy pinkish with age (hence the Ukrainian name, which means "red-gilled"). The spore print is white to pale pink, an important diagnostic feature (in Agaricus it's blackish brown).

The gills are free, meaning they don't reach the stem, crowded, with short gills in between. They are white or cream and darken only slightly with age.

The spore print is white to creamy. Pink or chocolate gills mean it isn't a dapperling but, for example, an Agaricus mushroom. Even so, a white print doesn't make a small parasol edible.

The stem is 5-10 cm tall and 0.7-1.5 cm thick, cylindrical, slightly thickened toward the base, white to cream and smooth. It has a simple membranous ring that's distinct in young mushrooms and may disappear with age.

The stem is 2–7 cm tall and only 2–5 mm thick, even or slightly thicker towards the base, smooth, silky, hollow and fragile. It's whitish or cream, pinkish or brownish towards the base, with white mycelial fluff at the very bottom.

The ring on the upper stem is white, thin, membranous and very fragile. Older specimens often have none at all, so a missing ring doesn't rule out a dapperling. There is no volva or sac at the base.

The flesh is medium-thick and white, with a barely noticeable pink tint at the base of the stem. It doesn't change colour when cut.

The flesh is thin and white and doesn't change colour when broken. Field guides describe the taste as mild or unremarkable.

Faint and neutral, with no distinct notes. Don't taste it — its safety status is undetermined.

The smell is strong and unpleasant: sharp, like rubber, coal gas or chemicals, which is how it earned the name 'stinking'. Some people pick up something fruity or sweetish in it. The smell helps identify the species, but it doesn't make the mushroom any safer.