Brick Cap

Hypholoma lateritium, also published as H. sublateritium, is the largest and most solidly built of the common Hypholoma species. It forms crowded clumps on stumps and buried wood, and its two-tone cap of brick or terracotta red at the centre grading to pale cream or buff at the margin is a reliable first impression once the eye is trained to it.

The genus Hypholoma sits in the family Strophariaceae, a group characterised by dark purple-brown to purple-black spore prints, gills that are attached rather than free, and a partial veil that leaves cobwebby fibres rather than a firm ring. In Hypholoma the veil is thin, so mature specimens usually show only a faint darkened band of fibres on the upper stem where falling spores have caught. The three species most often met in temperate woodland are the Sulphur Tuft, the Conifer Tuft, and this one.

It is a late-season fungus, often persisting well after the main autumn flush has finished, and clumps can still be found on frosty mornings when most other gilled fungi have gone.

Cap

The cap is 4-10 cm across, occasionally to 12 cm, convex and evenly domed for a long time before flattening. The surface is dry, smooth, and faintly silky, coloured brick-red, terracotta, or rusty tan over the disc and paling markedly towards a cream, buff, or straw-coloured margin. Young caps carry scattered whitish veil fragments hanging from the rim, which weather away with age.

Gills

The gills are adnate, crowded, and moderately narrow. They begin whitish to pale straw yellow, pass through a dull greyish or olive tone, and finish smoky purple-brown as the spores darken. They do not develop the vivid greenish-sulphur stage of some relatives.

Stipe

The stipe is 5-10 cm long and up to 1.5 cm thick, often curved where clumps crowd each other, firm and fibrous. It is pale cream or whitish in the upper part and becomes progressively rusty brown to reddish brown towards the base, with fine silky longitudinal fibres. There is no membranous ring; instead there is an indistinct fibrillose ring zone, usually darkened by trapped spores.

Flesh and spore print

The flesh is thick and firm for the genus, whitish to pale yellow in the cap and browner in the stem base, and it does not change colour dramatically when cut. The odour is mild and mushroomy. The spore print is purple-brown to purple-grey.

Brick Cap is a wood-decay fungus of broadleaf trees, appearing in dense tufts on cut stumps, fallen trunks, and above buried roots and stumpwood, so clusters can seem to come straight out of the soil. Oak and beech are the commonest hosts, with birch, elm, ash, and other hardwoods also used. It is much less often reported on conifers than its relative the Conifer Tuft.

The season is late, mainly from early autumn into the first frosts and sometimes into early winter in mild areas. It is widespread across temperate Europe, eastern North America, and eastern Asia, being generally common in managed woodland, parkland, hedgerows, and any place where hardwood stumps have been left in the ground.

This is a saprotroph causing a white rot, meaning its enzymes break down lignin as well as cellulose and leave the residual wood pale, soft, and fibrous. It colonises dead heartwood and stumpwood, sometimes moving into wood already occupied by other decay fungi, and its mycelium can persist in a single large stump for many years, producing a new crop of tufts each autumn.

By dismantling stump and root systems it plays a substantial part in returning carbon and nutrients from felled or fallen hardwoods to the soil, and the softened wood it leaves behind becomes habitat for invertebrates and a rooting medium for seedlings. Fruiting bodies emerge in tight fascicles from a shared mycelial base, which crowds and distorts the stems and gives the genus its tufted appearance.

Sulphur Tuft, Hypholoma fasciculare, is the closest match in habit but is smaller and slimmer, with a uniformly sulphur-yellow to greenish-yellow cap that lacks the brick-red centre, and it passes through an unmistakable greenish-yellow gill stage before turning purple-brown. Conifer Tuft, Hypholoma capnoides, has a duller tawny to ochre-orange cap without the sharply contrasting pale margin, gills that go from whitish straight to grey and then smoky purple with no yellow or green stage, and it fruits on conifer stumps.

The Spectacular Rustgill, Gymnopilus junonius, forms similar large orange-tan clusters on hardwood stumps but is separated by its rusty-orange spore print, distinctly yellow to rusty gills, and a well-formed membranous ring. Pholiota species growing on the same stumps generally have viscid or scaly caps, rusty brown spore prints, and often scaly stems, none of which fit the smooth, dry, two-toned cap and purple-brown print of Brick Cap. Honey Fungus, Armillaria species, also tufts on stumps but has a white spore print, decurrent gills, and a persistent ring.