Stinking brittlegill or Poisonpie

The cap is 5–12 cm across, up to 15 cm or more in big specimens. In young mushrooms it is rounded and firm, with the margin pressed against the stem, which is why it looks like a fist. It then becomes convex, later flat, with a shallow dip in the centre.

The colour is honey yellow, ochre or yellowish brown, often blotchy, and old caps develop reddish-brown to almost black spots. The surface is shiny, very slimy in wet weather and sticky as it dries. The margin carries deep radial grooves and small bumps, more pronounced the older the mushroom.

The cap is 4-10 cm, hemispherical at first, then flat-convex with a broad umbo. It's sandy yellow to creamy brown, darker in the centre. The surface is sticky (hence the Ukrainian name, “sticky hebeloma”): distinctly slimy in wet weather and glossy, as if varnished, when dry.

The gills are cream or dirty white, turning yellowish with age and developing rusty and brown spots. They are brittle, free or narrowly attached, with short gills in between. In young mushrooms and after rain they often carry clear droplets that dry to brown dots.

The spore print is cream to pale yellowish. A brown print means it isn't a stinking brittlegill and could be the poisonous poisonpie.

The gills are crowded and notched-adnate to the stem, white at first and turning reddish brown as the spores mature. In young mushrooms they bead with distinctive “droplets” of moisture, a diagnostic feature of the genus Hebeloma. Spore print rusty brown.

The stem is 5–10 cm tall and 2–4 cm thick, cylindrical or barrel-shaped, white, spotted brown with age, especially at the base. It starts solid, but chambers with a dirty brown lining soon form inside, and an old stem is hollow and crumbly.

There is no ring and no volva at the base.

The stem is 3-10 cm tall and 1-1.5 cm thick, often with a club-shaped, thickened base. It's white, yellowing with age, especially toward the bottom, and covered with a fine white mealy bloom. No ring.

The flesh is white and firm, later brittle, and either doesn't change colour when broken or slowly browns. The taste is bitter and burning, the gills most of all.

The flesh is white or creamy, yellowing slightly in old mushrooms, and doesn't change colour when cut. It's firm but not springy.

The smell is strong and unpleasant: rancid oil, and rotting fish or herring in old specimens. Some people compare it to a chlorinated swimming pool, others to raw potato. Similar brittlegills that smell pleasantly of bitter almonds are different species.

A distinct radish smell is the key diagnostic feature; some authors call it “rotting radish.” The taste is bitterish and unpleasant. Don't taste it raw: it's mildly toxic.