Spring Brittlestem

Spring Brittlestem, Psathyrella spadiceogrisea, is one of the earliest members of the genus to fruit, often appearing alongside morels and St George's mushroom while most other brittlestems wait for autumn. It belongs to the Psathyrellaceae, a family of thin-fleshed, dark-spored agarics with brittle hollow stems.

The species is typical of the genus in form — a small, smooth, strongly hygrophanous cap on a fragile pale stem — and is distinguished largely by its season, its rich date-brown colouring when wet, and its habit of growing in loose troops on damp, humus-rich soil under broadleaved trees.

As with much of Psathyrella, the group is taxonomically complex and several closely similar spring-fruiting forms are recognised. In the field the combination of early season, date-brown fading cap and dark brown spore deposit narrows things down considerably.

Cap

2-6 cm across, at first convex to broadly bell-shaped, becoming flattened with age and often with a low umbo and a finely lined margin when moist. Strongly hygrophanous: rich date-brown or reddish-brown when wet, fading unevenly to greyish buff, pale tan or almost whitish as it dries, so the same troop may show two-toned caps. Very young caps may carry a few white veil fibrils along the edge.

Gills

Adnate, moderately crowded and fairly broad. Pale greyish-brown when young, becoming dark brown with a slight purplish cast, the edges remaining paler and finely white-flocculose.

Stipe

4-9 cm long, 3-6 mm thick, straight, hollow, brittle and white to pale cream, sometimes with fine silky fibrils and a slightly enlarged base. There is no ring, though a faint fibrillose zone may show on very fresh specimens.

Flesh and spore print

Flesh thin and watery, brownish in the moist cap and white in the stem, with a mild indistinct smell. Spore print dark brown, sometimes with a purplish tone.

The species fruits on the ground in damp deciduous woodland, on humus-rich soil, along woodland tracks, in hedge bottoms and among leaf litter, generally in association with buried twigs, roots and rotting wood fragments. Beech, oak, ash, elm and poplar woods are all typical settings, and it also turns up in parks and along riverbanks.

It is widespread across temperate Europe and occurs in North America. Fruiting is concentrated in spring and early summer — roughly April to June in much of its range — with occasional later flushes after heavy rain, making it one of the few brittlestems commonly encountered before autumn.

Psathyrella spadiceogrisea is a saprotroph, decomposing buried woody debris, fallen twigs and leaf litter incorporated into the soil surface. Its mycelium spreads through the humus layer, breaking down cellulose and lignin residues and contributing to the rapid nutrient turnover of damp woodland floors.

The fruiting bodies are ephemeral, appearing after periods of rain, maturing within a few days and then collapsing or drying out. Early-season fruiting lets the species exploit substrates and moisture conditions in the window before summer drying and before the autumn peak in fungal competition, and troops often reappear year after year over the same patch of buried wood.

Psathyrella candolleana fruits later in the season, has a paler cream to honey-yellow cap and a distinctly toothed veil-fringed margin, and its gills flush lilac before darkening. Psathyrella piluliformis grows in dense tufts on stumps and hardwood, not scattered on soil, and has more reddish-brown caps.

Psathyrella multipedata has a much thinner stem and forms fused bouquets from a single base. Small Agrocybe species that also fruit in spring can look similar but have a firmer, non-brittle stem, often a ring, and a duller brown spore print rather than the dark purplish-brown of the brittlestems.