How to tell Shiitake from Funeral bell

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 small, 1.5 to 5 cm across and rarely up to 7 cm. It starts convex with an inrolled margin, then opens out almost flat, sometimes with a small bump in the middle.

The colour is honey yellow, ochre or tawny brown. The surface is smooth and slightly sticky in wet weather, and the margin is translucent, so you can see the lines of the gills through it. The cap is hygrophanous: it turns noticeably paler as it dries and is often two-toned. Sheathed woodtuft changes in exactly the same way, so cap colour won't separate them.

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 or run slightly down it, and they are crowded and narrow. Pale ochre or yellowish at first, they turn rusty brown as the spores ripen.

The spore print is rusty brown. That rules out honey fungus and velvet shank (white prints) and sulphur tuft and conifer tuft (purple-brown to almost black). It won't rule out sheathed woodtuft, though, whose print is the same colour. The spores are warty, roughly 8–10 × 5–6 µm, clearly larger and rougher than the smooth spores of woodtuft, but that only shows under a microscope.

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 slender, 2 to 7 cm long and 3 to 8 mm thick, even, and hollow with age. It is pale at the top and darkens to brown or reddish brown towards the base. Below the ring it is covered in pale silvery fibres running lengthwise, without the shaggy scales of sheathed woodtuft. White felty mycelium is visible at the base.

The ring is thin, membranous, whitish to yellowish, and soon turns brown from the spores. It's fragile: often all that's left is a brown band on the stem, and old specimens can lose it entirely. So a missing ring doesn't mean it isn't a funeral bell. There is no volva at the base.

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 thin, yellowish to watery brown and darker in the stem. It doesn't change colour when cut.

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.

The smell is often mealy, like fresh flour, especially when the mushroom is crushed. It can also be very faint, so field guides don't treat smell as a reliable feature, and it won't tell a funeral bell from a woodtuft.