Ochre Brittlegill Identification Guide

First impression, and the setting

Late autumn, a mixed wood with oak or beech over acid soil, or a plantation of spruce with a deep needle carpet, and there in the leaf litter sits a solid, dull yellow-ochre cap the size of a small apple. It looks matt rather than glossy, a little grubby, and it stands on a stout white stem that is often streaked with grey. Nudge it and the whole thing feels heavy, dense and slightly chalky.

That is the ochre brittlegill, and it is one of the most abundant woodland fungi across the temperate northern hemisphere. It fruits late, often carrying on when much of the autumn flush has finished, and you will typically find several scattered over a few square metres rather than a single fruitbody.

The dull colour is important. This is not a bright chrome yellow or an egg yolk yellow; it is a muted ochre with an olive or greenish cast on many specimens, and it fades toward pale buff in dry weather or strong light.

Confirming you are in the right genus

Before working on species, prove the genus, because that saves a great deal of time.

Take a fruitbody, hold it by the cap and snap the stipe across with your thumb. A brittlegill stem breaks the way a stick of blackboard chalk breaks, with a clean granular fracture and no fibrous strings. That is because the flesh is built largely from spherical cells rather than long fibres. A fibrous stem that tears into threads sends you elsewhere.

Then check for latex. Break a gill or nick the cap flesh and watch for thirty seconds. Brittlegills produce no milk. If a white or coloured droplet wells up, you are in Lactarius territory instead.

Finally, look at the stipe surface. There is no ring, no volva, no scaly girdle, just a plain white or greying cylinder.

Working through the cap

The cap is 4 to 10 cm across, occasionally larger, starting convex and firm, then flattening, then developing a shallow central depression as it expands. Old caps become saucer-shaped with a slightly wavy, sometimes shallowly grooved margin.

Colour is the dull ochre-yellow already described, usually a little darker and more olive at the centre, sometimes washing out to straw or pale buff at the edge. The surface is matt and dry in fair weather and becomes slightly tacky in the wet, so that needles and leaf fragments adhere to it.

Test the cuticle. Grip the skin at the margin and peel inward: on this species it typically strips about halfway to two-thirds of the way to the centre, coming away as a thin, slightly elastic film. Underneath, the exposed flesh is white, not tinted.

The margin is smooth and even in young specimens and only becomes faintly grooved with age, which is worth noting because heavily and prominently striate margins from an early stage point to a different group of brittlegills altogether.

Working through the gills

Turn the cap over. The gills are moderately close, fairly broad, and attached narrowly to the stem apex or almost free from it. Colour begins pure white and drifts to pale cream as the spores mature; it never becomes yellow-ochre or rusty.

Two textural checks are worth doing. Run a fingertip sideways across the gill edges: brittlegill gills shatter rather than bend, and you should see small chips break away rather than a rubbery fold. Then look at the pattern near the stem. In this species most gills run the full radius, with occasional forking near the attachment and few or no short intermediate gills.

Working through the stipe, base and flesh

The stipe is 3 to 8 cm tall and 1 to 2.5 cm thick, cylindrical or slightly swollen toward the middle or base, and finely wrinkled lengthwise. It is white when young and fresh, but here is the useful character: it greys steadily with age, in damp weather, and where it has been handled, taking on a dull ash or pale slate tone that is quite distinct from the yellowing seen in some relatives.

Slice it lengthwise. Young stems are solid and firm; older ones become soft, spongy and finally hollow or irregularly chambered in the middle, and the cavity walls often show that grey discolouration first.

Cap flesh is white, thick and firm and does not change colour appreciably on exposure. There is no reddening, no blueing, no immediate darkening. Any change that does occur is a slow drift to dull grey.

Taking and reading the spore print

The spore print is genuinely diagnostic in this genus, and it is worth the wait.

Cut the cap free at the top of the stipe, lay it gills down on a sheet of white paper or, better, on a piece of glass or clear plastic, cover it with a bowl or cup, and leave it four to eight hours or overnight. A mature, freshly expanded cap gives a heavy deposit; buttons and shrivelled old caps give little.

Scrape the deposit into a compact heap with a blade before judging colour, because a thin scattered dusting always looks paler than it really is. View it in daylight against white. The ochre brittlegill gives a white to pale cream print, at the pale end of the brittlegill range. A deep ochre or orange-yellow print rules the species out immediately, and that single observation removes a whole tranche of yellow-capped candidates.

Under a microscope the spores are broadly ellipsoid, ornamented with warts and short connecting ridges that stain blue-black in iodine solutions, which is the standard amyloid ornamentation of the genus.

Substrate, season and company

The ochre brittlegill is ectomycorrhizal, forming sheathing root partnerships with trees rather than rotting wood. It is a generalist by brittlegill standards, associating with both broadleaves and conifers: oak, beech and birch on the deciduous side, spruce and pine on the coniferous side.

It prefers acid to neutral soils, does well in leaf litter, mossy banks and needle carpets, and is common in plantations as well as ancient woodland. Fruiting runs from late summer well into autumn and often continues after the first cold nights, making it one of the later brittlegills still standing.

Separating it from close look-alikes

Russula claroflava, the yellow swamp brittlegill, is a brighter, cleaner chrome to egg-yellow, grows specifically with birch in wet ground, boggy hollows and sphagnum, and greys or blackens far more strongly and rapidly in all its tissues. Its cap surface is smoother and shinier, and its print runs a touch deeper.

Russula fellea is uniformly straw to honey-coloured throughout, and that is the point: cap, gills and stipe all share the same pale ochreous tone, whereas the ochre brittlegill keeps a white to cream gill and a white to grey stipe against a distinctly darker cap. It is also strongly tied to beech.

Lactarius species with yellowish caps are excluded by the milk test.

Tricholoma and Hebeloma species may look superficially similar in the litter but have fibrous, non-shattering flesh, and Hebeloma gives a brown print.

Field checklist

Chalky snapping flesh, no milk, no ring; dull ochre-yellow cap peeling halfway; white to cream gills; white stem that greys with age and hollows out; unchanging white flesh; white to pale cream spore print; with broadleaves or conifers on acid soil, late in the season.