Plums and Custard

Plums and Custard is one of the best-named fungi in the field guides: a yellow ground colour overlaid with plum-purple scales, sitting above gills the colour of thick custard. Once seen it is almost impossible to confuse, and it stands out sharply against the dark wood of old conifer stumps.

Tricholomopsis means resembling Tricholoma, reflecting the fleshy build and sinuate gills of the genus. Unlike true Tricholoma, which are mycorrhizal and grow from soil, Tricholomopsis species are wood decomposers found on stumps, logs, and buried conifer roots.

The intensity of the purple scaling varies. Young caps can be almost uniformly wine-red, while old, weathered specimens fade and spread their scales apart to reveal much more of the yellow background, which sometimes causes confusion with the paler relative T. decora.

Cap

Typically 4-12 cm across, convex then broadly flattened, sometimes with a low umbo. The bright yellow surface is densely covered with fine fibrillose scales in wine-purple, maroon, or brick-red, densest at the centre and thinning towards the margin, so that older caps show progressively more yellow between the scales.

Gills

Sinuate to adnexed, crowded, fairly broad, and a vivid egg-yellow to golden yellow, sometimes with a finely fringed edge. The colour is one of the most consistent features and remains bright even in weathered specimens.

Stipe

Stout and firm, 4-10 cm tall and 1-2 cm thick, cylindrical or slightly clubbed and often curved where it emerges from wood. It is yellow beneath a covering of reddish to purplish fibrils and small scales, densest below, and lacks a ring.

Flesh & spore print

The flesh is thick and pale yellow, unchanging when cut. The spore print is white, which together with the yellow gills separates the species at once from rusty-spored wood mushrooms of similar colouring.

It fruits on the stumps, fallen trunks, and buried roots of conifers, most often pine and spruce, and occasionally on sawdust piles or on hardwood in mixed stands. Fruit bodies grow singly, in small groups, or in loose tufts, sometimes emerging from soil directly above a buried root.

The season runs from summer to late autumn, with peak fruiting in early autumn. It is widespread and common throughout the conifer forests and plantations of Europe, northern Asia, and North America, and is frequently found in commercial forestry, shelterbelts, and parkland conifers.

Plums and Custard is a saprotrophic wood decayer causing a brown rot in conifer wood, breaking down cellulose and leaving the residual lignin as a crumbly brown mass. It typically colonises stumps and large roots and can fruit from the same stump for many consecutive years.

Because it feeds on dead conifer wood rather than partnering with living roots, its distribution follows felling and windthrow rather than the condition of living trees. Old plantation stumps often support long-lived colonies, and repeated flushes appear around the stump collar or from soil above decaying roots.

Tricholomopsis decora is the closest relative, with the same yellow gills and wood habitat but with dark olive-brown to blackish scales on a yellow cap instead of purple-red ones, and a generally smaller stature. Gymnopilus junonius grows in large tufts on stumps and is tawny-orange with yellow gills, but it has a distinct ring on the stem and a rusty-brown spore print.

Pholiota species on wood are scaly and yellow-brown but produce brown spore deposits and often have slimy caps. Tricholoma species may share the sinuate gills and white spore print but grow from soil in mycorrhizal association with trees rather than directly from stumps and logs.