Sheathed Woodtuft Identification Guide

The first impression

Sheathed Woodtuft is a mushroom of dead broadleaved wood, and the clue that usually stops you is a colour effect rather than a shape. On a mossy birch or beech stump, or on a fallen willow trunk half-sunk in litter, you see a crowded tuft of twenty or more medium-sized brown caps, and they are not all the same brown. Some are a rich date-brown, some are pale ochre-yellow, and many are two-toned, with a pale centre and a darker outer band, or the reverse. That patchwork within one tuft is the hallmark of the species, and it comes from the way the caps lose water. Spring and autumn are both productive, and the tufts can be large enough to cover a whole stump face.

Reading the cap

Caps run 2 to 6 cm across, convex at first with an inrolled edge, then flattening with a broad low central hump. The surface is smooth, without scales or fibrils, and is slightly greasy to the touch in wet weather, drying matt.

The important property is that the cap is water-loading. When fully wet it is uniformly dark date-brown to cinnamon and the margin is faintly translucent, so the lines of the gills show through as fine radial streaks. As it dries, the colour lifts from the centre outwards to a pale tan or ochre-yellow, leaving a sharply defined darker band around the outer part of the cap. Catch a cap mid-way through that process and you have the classic two-zoned appearance. Never judge this species on the colour of one cap alone; look at the range across the tuft, because a single drying event can produce every intermediate.

Gills and how they change

Gills are attached to the stipe, broadly adnate and often running a very short way down it as a fine decurrent line. They are moderately crowded, fairly narrow and pale clay to buff when young, then deepening steadily to a warm cinnamon or rust-brown as spores develop. The gill edges tend to stay slightly paler than the faces, which is easiest to see with a lens.

A useful supporting check is the powdering on the caps of the lower mushrooms in a tuft, which is a warm brown rather than a dull purple-grey or a chocolate tone.

Stipe, ring zone and base

This is where the identification is really made. The stipe is 3 to 8 cm long and 3 to 10 mm thick, usually curved because the caps orient themselves away from the wood, and often fused with neighbours at the base.

Divide it mentally into two zones. Above the ring the surface is pale ochre, smooth, and very finely silky. At the level of the ring there is a fibrous, sometimes slightly membranous collar which quickly becomes dusted rust-brown by falling spores and can weather to a mere darkened band. Below that line the stipe is progressively darker and, crucially, clothed with small dark brown, recurved, scaly fibrils that give it a rough, sheathed texture and that grow more concentrated towards the base. Run a fingertip up the stem and you will feel the change from rough to smooth as you cross the ring zone.

At the very bottom, the stipe darkens to blackish brown and is often bound into a common mass with others, attached directly to the wood or to bark-covered roots. There is no sac, no bulb and no volva of any kind.

Flesh and colour change

Slice a fruit body lengthways. The flesh in the cap is thin and watery ochre-brown when hydrated, drying pale, and in the stipe it is fibrous, tougher and browner, becoming almost dark brown near the base. There is no colour change on cutting other than the slow browning of the exposed surfaces, and no bruising to blue or red anywhere. The smell is faintly aromatic and pleasantly woody, without any strong mealy note.

Taking a spore print

Select a fully expanded cap from the middle of the tuft, cut the stipe flush, and set the cap gills-down on white paper under a cover for four to six hours. The deposit is a clear ochre to cinnamon brown, warm rather than dull. Heap it up before judging.

That print immediately excludes the two large groups of brown-capped mushrooms that share stump habitats with it: the honey fungus group prints white, and the tufted Hypholoma species print a dull purple-brown. It does not, on its own, separate the closest relative, so use the print as a filter rather than as the final answer.

Substrate, season and ecology

Sheathed Woodtuft is a wood recycler. It fruits from stumps, fallen trunks, buried roots and large branch fragments of broadleaved trees, especially birch, beech, alder, willow and poplar, and it is far less often found on conifers. The wood is usually well rotted and soft, and the tufts emerge from cracks, cut faces and bark splits.

Because it works through white-rotted wood, it recolonises the same stump over several years, and a productive stump often carries tufts in both a spring and an autumn flush, with the main season running from late summer into November. Damp, sheltered situations produce the largest tufts, and after rain a stump can carry several tiers of them.

Separating it from close look-alikes

Galerina marginata is the species you must actively rule out, and the work is done on the stem, not the cap. Its stipe below the ring is silky-fibrillose and overlaid with a whitish or pale fibrous sheen; it never carries the small dark brown recurved scales that make the lower stem of Sheathed Woodtuft rough to the touch. Its ring is a thinner, more membranous flange that often vanishes entirely, its cap dries more evenly without forming the sharp two-tone band, its fruit bodies are usually smaller and in looser groups, and it is common on conifer wood as well as hardwood. A distinctly mealy smell is a further pointer away from Sheathed Woodtuft. Under a microscope the difference is decisive: Galerina spores are roughened or wrinkled with a smooth pale patch, while Sheathed Woodtuft spores are smooth with a small germ pore.

Hypholoma fasciculare and Hypholoma capnoides form similar tufts but have smooth, unbanded, yellowish stems with no scales, sulphur-yellow to grey-blue gill tones when young, and purple-brown spore prints.

Pholiota species share the ring zone and scaly stem but have distinctly scaly caps and generally brighter yellow or golden ground colours.

Armillaria species are larger, with fine dark fibrils on the cap centre, whitish gills, a thick white membranous ring and a white spore print, plus black bootlace strands under nearby bark.

Psathyrella species growing on stumps are much more fragile with strongly hygrophanous caps, but they have blackish spore prints and brittle hollow stems that snap cleanly with no ring at all.

Working order

Tuft on rotting broadleaved wood; smooth two-tone drying cap; adnate cinnamon gills; ring zone with a dark scaly stem below it and a smooth pale stem above; ochre-brown print. Confirm all five and the identification holds.