Wood Blewit

The Wood Blewit is the best known member of Lepista, a small genus of fleshy, ringless, pink-spored agarics closely allied to Clitocybe, and it is frequently listed under the alternative combination Clitocybe nuda. It is one of very few large temperate mushrooms that are genuinely violet, and in fresh condition the cap, gills and stem are all suffused with the same lilac to blue-violet tone.

Its season is unusually late. While most woodland agarics have finished by the end of October, the Wood Blewit is only beginning, and it fruits through November, December and often into January in mild spells, tolerating light frost that flattens almost everything else. This combination of a violet fungus appearing at the turn of the year makes it one of the most recognisable late-season finds.

Colour is variable and fades markedly with age and dry weather, so old fruit bodies can be tan, buff or dingy brown with only a hint of lilac left at the stem apex and on the gill edges. For that reason the pale pink spore print, the sinuate gill attachment and the fibrous violet-flushed stem base are the characters that carry the identification rather than colour alone.

Cap

5-15 cm across, at first convex with a strongly inrolled margin, expanding to flat or shallowly depressed, sometimes with a wavy outline. The surface is smooth, bare and slightly greasy or moist in damp weather, never scaly or fibrillose. Colour is bluish lilac to violet when fresh, fading through pinkish buff to tan and finally dull brown, usually retaining more violet toward the margin.

Gills

Crowded, fairly narrow, and sinuate to adnate, notched where they meet the stem and frequently appearing to be easily separable from the cap flesh with a fingernail. They are the same lilac-violet as the cap when young and slowly dull to buff-pink or pale brownish with a pinkish cast.

Stipe

5-10 cm tall, 1.5-3 cm thick, solid, firm and distinctly fibrous, often longitudinally streaked. It is lilac to violet, usually the last part to lose its colour, and is swollen or clubbed at the base, where it is bound into a mat of lilac-tinged mycelium and adhering leaf litter. There is no ring and no volva.

Flesh and spore print

The flesh is thick, soft, pale lilac to whitish, and does not change colour dramatically when cut. The spore print is pale pink to pinkish buff, never white and never rusty. Under the microscope the spores are minutely warted and ellipsoid, a character shared across Lepista.

Lepista nuda grows in deep leaf litter, needle duff and other accumulated plant debris. Classic sites are beech and oak woodland with a thick leaf layer, mixed and coniferous plantations, hedge bottoms, shelter belts, shrubberies, compost heaps and garden borders under mulch. It appears equally readily in managed ground as in ancient woodland, provided there is a good depth of decomposing litter.

Fruiting begins in late autumn, typically from late October, and continues through winter until sustained hard frost. Fruit bodies grow scattered, in troops, in dense clusters, and very often in conspicuous arcs and fairy rings among the leaves. The species is common and widespread across Europe, temperate Asia and North America, and has been introduced with landscaping materials elsewhere.

The Wood Blewit is a saprotroph and one of the more important late-season litter decomposers in temperate woodland. Its mycelium binds and permeates fallen leaves and needles, breaking down cellulose, hemicellulose and lignin and accelerating the conversion of the autumn leaf fall into humus. The characteristic pale lilac mycelial mat and the mass of leaves stuck to the stem base are direct evidence of this activity.

By fruiting so late it exploits a window when the year's leaf fall is fresh and abundant and when competition from other litter fungi has largely ceased. Its tolerance of low temperatures allows spore release to continue through mild winter weather, and the ring and arc growth pattern reflects a long-lived mycelium spreading outward through the litter layer season after season.

The Field Blewit, Lepista saeva, is the closest relative and shares the pink spore print, but its cap is plain pale buff to greyish brown with no violet at all, while the lilac colour is restricted to the streaky stem. Other Lepista species such as L. sordida are smaller, thinner-fleshed and more hygrophanous, with the same violet tones on a much flimsier fruit body.

Several Cortinarius species, notably Cortinarius violaceus and members of the Cortinarius alboviolaceus group, are also violet. They are separated by the cobwebby cortina veil that leaves fibrous remnants on the upper stem, by gills that mature rusty brown, and by a rusty brown spore print rather than pink. Cortinarius violaceus additionally has a dry, felty to scaly cap surface quite unlike the smooth, greasy cap of the Wood Blewit.

Mycena pura shares a lilac-pink palette but is a small, slender, thin-fleshed mushroom with a hollow stem and a white spore print. Purple-tinted Laccaria amethystina is smaller still, with widely spaced thick gills, a tough fibrous stem and a white print.