Shiitake or Scaly sawgill

The cap is 5–20 cm across, usually 5–10 cm in shop mushrooms. Young caps are domed with a tightly inrolled edge, then become convex and finally almost flat, with a wavy margin in old mushrooms.

The colour ranges from pale tan to dark brown or reddish brown, paler towards the edge and fading with age. The surface is felty and fibrous, with small whitish scales that are densest near the margin, where white shreds of the veil hang. Some varieties, known in China as flower shiitake (huagu), have caps that crack into a white network on a dark background. This comes from the way they are grown and is not a separate species.

The cap is up to 13 cm across, hemispherical when young, then flattening to plano-convex. It's whitish or pale brownish, with distinctive dark scales in concentric rings, concentrated mostly toward the centre. The margin stays inrolled for a long time.

The gills are crowded, white or cream, and attached to the stem, sometimes running slightly down it. In young mushrooms a white cobwebby veil covers them. With age and handling the gills turn brownish and their edges become ragged and saw-toothed.

The spore print is white. That is the key feature separating shiitake from brown mushrooms with a rusty print, including the poisonous funeral bell.

The gills are attached to the stem and often run down it. They're white when young, turning yellowish and darker with age, and reddish brown in old mushrooms. The edges are toothed and uneven, a typical feature of the genus.

The stem is 3–5 cm tall and about 1 cm thick, central or slightly off-centre, often curved and narrowing towards the base. It is firm, tough and fibrous, pale brown, with woolly scales below the cap.

There is no true membranous ring, only a fibrous ring zone left by the veil, and no volva at the base.

The stem is up to 12 cm tall and 1–2 cm thick, cylindrical. It's white, with distinctive dark scales below the ring, and creamy white and smooth at the top. The ring is white and membranous, and often disappears in mature mushrooms.

The flesh is white, firm and springy, thick in the centre of the cap and thin at the edge. In the stem it is tough and fibrous. A cut surface hardly changes colour, though the flesh slowly browns in old mushrooms. The taste is mild and rich, with a strong umami note.

The flesh is white and springy when young, becoming very tough and leathery with age, until it's as fibrous as old wood. It doesn't change colour when cut. Old ones are hopeless for cooking.

The smell is pleasant, mushroomy and slightly spicy. It is noticeably stronger in dried shiitake, which is why dried mushrooms are added to dishes for their aroma.

A faint smell of anise, stronger in young mushrooms and almost gone in old ones. The taste is mild when young; old ones taste bland, sometimes a little “woody”.