Golden Scruffy Collybia Identification Guide

The first impression

This is a mushroom you find by looking down at a wet stick. You are in humid summer woodland, ideally after several days of rain, working over the litter layer of a moist broadleaved forest, and something small and vividly orange is standing on a decaying branch on the ground. It is only a centimetre or two tall. From directly above, the cap looks like a fragment of orange peel that has been rolled in coarse sugar: it is granular, bristling, matt, and utterly unlike the smooth or slimy surfaces of most small orange woodland fungi.

Golden Scruffy Collybia is small enough to be missed and distinctive enough that once you have seen one you will never mistake it again. The whole identification comes down to three things: the erect spiny-granular ornamentation, the thick distant white gills underneath, and a white spore print.

Cap

The cap is 5 to 25 mm across, convex to bluntly conical when young, expanding to broadly convex or nearly flat, often with a slight central depression in age and sometimes with a low umbo. The margin can carry hanging remnants of the same granular tissue that covers the surface.

The surface is the character. Over a bright golden-yellow to orange-yellow ground it is densely covered with small, erect, pointed, pyramidal to granular scales or spines, each a fraction of a millimetre high, giving a texture like fine sandpaper or a miniature sea urchin. These are not appressed patches and not fibrils laid flat: under a hand lens they stand up. They are firmly attached but can be rubbed off with a thumb, leaving a smoother paler surface, and they gradually wear away in weathered specimens, especially at the margin, so the centre stays scruffier than the rim.

Colour is most saturated in young material and fades with age and sun toward orange-buff, dull yellow-ochre or even pale tan. The cap is dry at all times, never viscid.

Gills

Turn it over and the contrast is striking: against that hot orange cap the gills are white to cream, sometimes faintly yellowish where they meet the cap edge. They are notably thick, broad, waxy-looking and distant to subdistant, so you can count them individually without a lens, which is unusual in a mushroom this small. Attachment is adnate to slightly decurrent, and short gills are interspersed between the full ones. In good material you can see low cross-veins or interconnecting ridges between adjacent gills near the stipe.

Gill edges are even and white, with no coloured marginate band. There is no coloured juice and no beading.

Stipe, base and flesh

The stipe is 1 to 4 cm long and 1 to 3 mm thick, more or less equal or slightly enlarged at the base, central, and usually curved because these mushrooms sprout from the sides of sticks and turn upward. It carries the same yellow to orange-yellow colour as the cap and, importantly, the same granular-scurfy covering over most of its length, so the stipe feels rough between the fingers. The apex is often paler, sometimes whitish and smoother.

At the base there may be a small pad of pale mycelium binding wood fibres, but there is no volva, no ring, no ring zone and no rooting extension. There is no membranous partial veil at any stage.

Flesh is whitish to pale yellowish, very thin in the cap, tough and slightly fibrous in the stipe. Cut a cap and stipe lengthways and watch for a few minutes: nothing changes colour, there is no latex, no blueing and no reddening. The odour is mild or indistinct.

Taking and reading a spore print

Small caps demand patience. Cut the cap free at the stipe apex, place it gills-down on white paper, cover it with a cup to keep out draughts, and leave it overnight in a cool spot. Expect a thin but legible white deposit.

That white print is diagnostically important, because a great many small, scaly, brightly coloured wood-inhabiting mushrooms have rusty or brown prints. If your print comes out cinnamon or rust, you are not in this genus at all.

Under the microscope the spores are broadly ellipsoid to almond-shaped, smooth, colourless and relatively large for such a small mushroom, with thickish walls. There are prominent thin-walled cells on the cap surface making up the granular scales, which is what gives the cap its texture.

Substrate, season and setting

Golden Scruffy Collybia is a wood decayer of broadleaved material, and it prefers small-diameter stuff: fallen sticks, branches, twiggy debris and occasionally larger logs, generally well rotted, barkless or partly barkless, and lying in a damp shaded position on the forest floor. It is not found on conifer wood as a rule, and it does not grow from soil.

The season is warm and wet: summer into early autumn in warm-temperate regions, with fruiting following heavy rain and dropping off quickly in dry spells. Its overall distribution is broadly tropical to subtropical with an extension into warm-temperate zones, so it is recorded across the Americas, Asia, Africa, Australasia and the Pacific, and in North America it is most familiar in the southeast and southern Appalachians during humid summers.

Separating look-alikes on morphology alone

Flaming Scalycap (Pholiota flammans). Also bright yellow and scaly, but far larger, with a ring zone, gills that mature rusty, a rusty-brown spore print, and a preference for conifer wood. The print alone settles it.

Scurfy Twiglet (Tubaria furfuracea) and Phaeomarasmius erinaceus. Small scurfy mushrooms on twigs, but both are brown to rusty-brown rather than golden-orange, and both have brown spore prints.

Flammulaster erinaceellus. Small, granular-scaly and on hardwood, matching the texture well, but yellowish-brown to cinnamon-brown in colour with a brown spore print.

Variegated Mop (Tricholomopsis rutilans) and Tricholomopsis decora. Share a yellow ground colour, dark fibrillose scaling and white spore prints, but they are much larger, their scales are flat fibrils rather than erect granules, their gills are yellow rather than white, and they grow on conifer wood.

Orange Mycena (Mycena leaiana). Bright orange and on hardwood, but its cap is smooth and viscid, its stipe is slimy, and its gill edges are strongly orange-marginate. The absence of any granular texture is immediate.

Xeromphalina species. Small orange mushrooms on wood with decurrent gills, but smooth caps, tough wiry dark stipes and no scurf.

Waxcaps (Hygrocybe species). Thick distant waxy gills and bright colours do overlap, but waxcaps have smooth, often greasy caps and grow in grassland and mossy ground rather than on sticks.

Field routine

Find damp hardwood sticks after summer rain. Look for a small mushroom whose cap and stipe are both rough with erect orange granules. Confirm thick, distant, white gills below a bright cap. Take a white spore print overnight. Confirm that there is no ring and no colour change on cutting. That short sequence is sufficient without any microscopy.