Scurfy Twiglet Identification Guide

The setting and the first impression

This is the small brown mushroom you meet when almost nothing else is fruiting. December, January, a mild wet week, and you are walking a park path, a garden border, a hedge bottom with a ditch, or the woodchip mulch around municipal shrub planting. Scattered across the chips or pushing out of a mat of buried twigs are dozens of small tawny caps, 1 to 4 cm across, some deep date-brown and glossy with wet, others already dried to pale buff or cream in the centre with a darker rim.

That two-tone appearance within a single troop is the first useful signal. It means the caps are strongly hygrophanous, changing colour dramatically as they lose water, and it tells you at once that any description you write must specify whether the fruitbody was wet or dry.

Reading the cap

Start with a moist specimen. The cap is convex at first, then plano-convex and finally flat, sometimes shallowly depressed at the centre in age, with a margin that becomes wavy and often splits radially. Wet, it is date-brown, tawny-cinnamon or reddish-tan and the margin is translucently striate, so you can see the lines of the gills through the flesh for a few millimetres in from the edge.

As it dries, the pallor spreads outwards from the disc, giving a cream to ochre-buff centre and a browner rim, and the striations vanish. Neither state is more correct than the other; record both if the troop offers both.

Now look at the margin with a lens. Scattered over it, and often over the disc in young caps, are small whitish flecks and fibrils, the remains of a delicate veil. This scurf is the character behind the common name. It is fragile and heavy rain washes it away, so check several fruitbodies, and check the youngest ones, before deciding it is absent.

The gills

Turn a cap over. The gills are moderately spaced rather than crowded, fairly broad, and attached adnately to shortly decurrent, running a little way down the stipe in many specimens. Colour begins pale clay or ochre-buff and darkens to cinnamon or dull tan as the spores mature. The edges are paler, whitish and slightly uneven under a lens.

The important negatives here are colour-based. The gills never turn the dark grey-black of the brittlestems, and they never take on the bright rust-orange of the rustgills, so watching the mature gill colour is already doing useful diagnostic work.

The stipe and base

The stipe is 2 to 5 cm long and 2 to 5 mm thick, cylindrical, frequently curved because it grows out of loose chips, hollow, and coloured like the moist cap or a little paler. It is finely whitish-fibrillose, especially in the upper half, and minutely pruinose at the very apex.

There is no membranous ring. At most there is a faint fibrillose zone where the veil separated, easy to miss and often absent. Dig the base out rather than snapping the stipe: it should be clothed in conspicuous white mycelial down that binds woodchips, twig fragments and litter into a tight ball. That white basal mycelium anchored to woody debris is a solid supporting character.

Flesh and section

Cut lengthways. The flesh is thin, watery brown when moist and paler when dry, and it does not change colour on exposure. It is soft but not brittle: the stipe bends and tears rather than snapping cleanly like a piece of chalk, which is the practical difference from the brittlestems. The smell is faint, at most slightly mealy, and there is no latex.

Taking the spore print

Because several superficially similar small brown mushrooms share the same mulch beds, the print is the decisive laboratory-free test. Cut a mature cap free and set it gills-down on white paper, cover with a cup and leave it four to six hours or overnight; small caps deposit slowly, so give it time.

The deposit is pale ochre-brown to dull clay-brown, sometimes with a faint pinkish-tan cast in thick piles. It is emphatically not the bright rusty-orange of Galerina and Gymnopilus, and not the dark purple-brown or black of the brittlestems and their relatives. Under the microscope the spores are smooth, ellipsoid, roughly 6.5 to 9 by 4 to 5.5 micrometres, without a germ pore and not dextrinoid.

Substrate and season

The substrate list is short and useful: woodchip mulch, buried twigs, hedge clippings, garden beds, path edges, verges, hardwood debris and rotting sticks in litter. It also appears in unmulched woodland where fallen twigs are buried under leaves. It is a saprotroph on small-diameter hardwood debris, which is exactly why municipal mulch beds suit it so well.

Season is one of its best characters. It fruits from autumn right through winter into early spring, flushing during mild wet spells, and it tolerates frost, reappearing after a freeze looking limp but recognisable. A troop of small tawny caps on woodchip in January is already halfway to an identification.

Separating it from look-alikes on morphology alone

• Tubaria conspersa: the veil is far more developed, forming dense whitish to ochre floccose scales over the whole cap rather than scattered marginal flecks, and it favours grassy or mossy ground.
• Tubaria dispersa: associated with fallen hawthorn fruits, with more yellowish gills and a paler cap.
• Funeral Bell, Galerina marginata: grows on wood, usually visibly on stumps and logs, with a smooth cap lacking marginal scurf, a distinct membranous ring on the stipe, and a bright rusty-brown spore print; the spores are wrinkled with a smooth plage.
• Brittlestems, Psathyrella species: a very fragile stipe that snaps cleanly, gills going grey then blackish, and a dark purple-brown to black spore print.
• Conocybe species: markedly conical or bell-shaped caps on very slender fragile stipes, crowded gills, and a rusty-brown print.
• Fieldcaps, Agrocybe species: larger and firmer, with a smooth, non-hygrophanous, often cracking cap, a membranous ring in several species, and brown gills.
• Gymnopilus penetrans and relatives: brighter yellow-orange throughout, on conifer wood, with gills that develop rusty spots and a bright rusty print.
• Simocybe species: small, but with olive-tinged, velvety caps and a growth habit on exposed wood.

A working order

Habitat and season first, then look for the marginal scurf on the youngest caps, then note the hygrophanous two-tone cap, then the adnate to shortly decurrent clay-coloured gills, then the ring-free stipe with white twig-binding mycelium, then confirm with a pale ochre print. Photographing one wet and one dried cap side by side makes the record far more useful later.