How to tell Shaggy parasol from Stinking dapperling

The cap is large, 7-20 cm across, hemispherical at first, then opening out to convex and finally flat with a small boss. The background is a light greyish brown, covered in coarse brown scales arranged in concentric rings and darker toward the centre. It looks a lot like the parasol mushroom, but here the scales curl upward at the edges, which is a good field mark.

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: white at first, cream with age and pinkish in old mushrooms. Damaged gills turn red. The spore print is white, and that matters: it's how you tell it from the poisonous Chlorophyllum molybdites (green spore print).

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 7-20 cm tall and 1-2.5 cm thick, cylindrical and swollen at the base (a gradual bulb; an abrupt, rimmed bulb belongs to the related Chlorophyllum brunneum, which has no records from Ukraine in GBIF). It's whitish to greyish with no snakeskin pattern (unlike the parasol mushroom), and browns where touched or damaged. Near the top sits a fleshy, movable ring. There is no volva.

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 cap flesh is white and soft. The giveaway: when cut or damaged it quickly turns red, then turns brown. That's the fundamental difference from the parasol mushroom, whose flesh doesn't change colour.

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

A faint, pleasant mushroomy smell. The taste is mild, pleasant and mushroomy once boiled.

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.