How to tell Poplar knight from Tacked knight

The cap is 5-12 cm across, convex with an inrolled margin when young, later becoming flat and spread out with a slightly wavy margin. The skin is finely fibrous or smooth; slimy and sticky in wet weather, dry and matte when it's dry. The colour is reddish chestnut or reddish orange, richer at the centre and paler toward the margin. Old caps turn brownish chestnut with small cracks. The margin is even, with lengthwise grooves in damp conditions.

The cap is 5–15 cm across. Young caps are hemispherical to convex with an inrolled margin, then flatten out, sometimes with a shallow dip in the centre when old, and the edge can be wavy. The surface is smooth, without obvious radial fibres, slimy and shiny when wet and tacky when dry.

The colour is reddish brown, chestnut or yellowish brown, paler and greyish pink towards the margin, which isn't grooved. The cap often has small dark yellowish brown spots that look like dried drops, but some caps have none.

The gills are notched (emarginate) where they meet the stem, moderately crowded and fleshy. They start out whitish and age to cream with rusty spots along the edges. Spore print white.

The gills are white or cream, later pale brownish, crowded and notched or attached by a tooth at the stem. On old fruit bodies, and where they've been knocked, they develop rusty brown spots.

The spore print is white.

The stem is 5-10 cm tall and 1-2.5 cm thick, firm and cylindrical, thickening toward the base when young. It's whitish at the top and brownish lower down, with ochre-chestnut spots, and smooth with lengthwise fibres. No ring.

The stem is 3–8 cm tall and 1–2.5 cm thick, cylindrical, sometimes slightly wider at the base, firm, and may become hollow with age. It's white, smooth or faintly fibrous, slowly browns with handling and age, and is rusty brown at the base.

There is no ring, no ring zone and no volva. Nor is there a sharply defined white band at the top of the stem; that's more typical of Tricholoma albobrunneum.

The flesh is firm and white, and where cut it slowly takes on a creamy brownish tint. The smell is faintly mealy; the taste is mild at first, then bitterish and mealy, with the typical Tricholoma aftertaste.

The flesh is white and firm, sometimes brownish under the cap skin and at the stem base. It doesn't change colour noticeably when cut but slowly browns after long handling. The taste is mealy with a slight bitterness.

Faintly mealy, with a hint of fresh cucumber — typical of many knights.

The smell is mealy, like fresh flour; some authors describe it as stale, sourish flour. It doesn't help with identification, because the edible poplar and matt knights smell of meal too.