Lepiota brunneoincarnata Identification Guide

First impression

This is a small, neat dapperling that turns up in mown and grazed short turf rather than in deep woodland. The usual encounter is a scatter of three to a dozen fruit bodies, caps 2 to 5 cm across, standing in a park lawn, a roadside verge, a garden border, a hedge bank or the grassy strip beside a path, often within a few metres of planted broadleaved trees.

At arm's length the cap looks like a pale disc with a dark centre and a ring of small brown flecks around it, as though something had been dusted over cream paper and then rubbed away at the edges. That target-like zonation is the visual signature.

The habitat as first evidence

Record the site carefully, because habitat carries real weight in this group. Lepiota brunneoincarnata is a soil saprotroph of warm, rich, frequently calcareous or disturbed ground: parks and lawns, orchards, roadsides, hedge banks, dune grassland, garden beds and the grassy edges of tracks. It appears from late summer through autumn, usually a few days after warm rain, and it is at its most common in Mediterranean and continental climates, though it has spread widely in urban plantings.

Open turf plus a nearby broadleaf, rather than closed woodland litter, is a useful early steer within the small brown Lepiota species.

Step one: read the cap

Size and shape. Caps run 2 to 4 cm, occasionally 6 cm. They begin convex or bluntly conical, expand to plano-convex, and usually keep a low, broad, darker umbo at the centre.

Ground colour. Whitish-cream to pale pinkish-buff, best judged near the margin where the covering is thinnest.

The scales. This is the character that names the species. The cap skin breaks up into flattened, appressed scales of a dark vinaceous-brown, purplish-brown or greyish-brown. They are densest at the centre, where they run together into an unbroken dark disc, and they become progressively smaller and more widely spaced towards the margin, arranged in loose concentric rings. Hold the cap flat and look down on it: you should read distinct zones rather than an even coating.

Margin. Even, sometimes carrying a few fine pale fibrillose remnants of the partial veil, not striate.

Step two: read the gills

Cut a cap vertically down the middle rather than trying to judge attachment from below. In section you should see a clear gap between the inner ends of the gills and the top of the stem: the gills are free, and in some specimens they end against a faint collar.

They are crowded, moderately broad, soft, and white to cream, occasionally taking a faint pinkish-cream tinge with age. The gill edge is even and, under a lens, minutely flocculose. Look for gills of two or three different lengths interleaved between the full-length ones, which is normal in the genus.

Free white gills plus a small scaly cap already narrows the field to Lepiota and its immediate relatives.

Step three: read the stem

The stem is 2.5 to 4.5 cm long and 4 to 10 mm thick, cylindrical, sometimes slightly swollen at the base, and easily separated from the cap.

The important detail is the surface. Above the veil zone the stem is white and smooth to silky. Below it, the surface carries scattered fibrillose bands of pinkish-brown to vinaceous-brown, forming one or more indistinct woolly girdles rather than a neat, membranous, persistent ring. On mature specimens the girdles often break down completely, and the only remaining evidence is a sharp change from white above to brownish-pink below at the level where the veil once was.

There is no movable ring, no double ring, and no snakeskin patterning; those belong to much larger relatives.

Step four: flesh, colour change and odour

Split the whole fruit body lengthways. The flesh is white and fairly thin in the cap. In the lower stem it often shows a pinkish to vinaceous flush, either present already or developing slowly at the cut surface. That slow reddening in the stem cortex is a recurring feature of the species and is worth waiting a minute or two for.

There is no bluing, no greening and no latex of any kind. The odour is weak and slightly sweetish when fresh, becoming a little unpleasant in age, and it is specifically not the sharp, penetrating, rubbery smell of Lepiota cristata.

Step five: the spore print

Cut a mature cap and set it gills-down on card that is half black and half white, cover it, and leave it overnight. The deposit is white to very pale cream.

A white print does a lot of work. It removes every Agaricus, which gives a chocolate-brown deposit, and it removes the brown-spored genera that can superficially resemble a scaly cap in turf. Under a microscope, spores are small, roughly 6.5 to 9.5 by 4 to 5.5 micrometres, ellipsoid to ovoid with a rounded base, without a projecting spur, and strongly dextrinoid, staining red-brown in Melzer's reagent. That dextrinoid reaction is the genus-level confirmation for Lepiota in the strict sense.

Separating it from the look-alikes on morphology

Lepiota subincarnata is the closest relative and the hardest call. It is paler and pinker overall, its squamules are finer and distributed more evenly rather than in sharp concentric zones, and its tone is pinkish-brown rather than dark vinaceous or greyish. It also leans towards humus, mulch, wood chips and garden borders rather than open mown turf. Where the two overlap, judge the coarseness and darkness of the cap scales and the crispness of the concentric arrangement.

Lepiota cristata is smaller and more delicate, with rusty reddish-brown scales concentrated in the centre on a white ground, a small but genuinely membranous white ring on a smooth stem, a strong pungent rubbery odour, and spores that are spurred and triangular in profile.

Lepiota clypeolaria is taller and more slender, with an ochre-brown cap and a conspicuously shaggy, woolly stem below a fleeting ring, quite unlike the girdled stem here.

Cystolepiota and Echinoderma species have powdery, mealy or spiny cap coverings rather than flat appressed scales, and their surfaces smear when rubbed.

Macrolepiota and Chlorophyllum species are far larger, 10 to 30 cm, with a thick double movable ring and a snakeskin-patterned stem.

Young Agaricus species have gills that turn pink and then chocolate-brown, and a brown spore print.

Leucoagaricus leucothites is stockier, with a smooth whitish to cream cap lacking distinct scales and a well-formed persistent ring.

A working field sequence

1. Note the habitat: short turf, rich or disturbed soil, broadleaves nearby.
2. Measure the cap; 2 to 5 cm is expected.
3. Read the cap scales for dark vinaceous-brown, appressed and concentrically zoned on a cream ground.
4. Section the cap and confirm the gills are free and white.
5. Examine the stem for fibrillose brownish girdles and no true membranous ring.
6. Split the stem and watch for a slow pinkish flush in the base.
7. Take a print and expect white to pale cream.