Stinking Dapperling

The Stinking Dapperling is by some margin the commonest small Lepiota in Europe and North America, and for many people it is the first member of the genus they learn. Lepiota sits in the family Agaricaceae alongside the field mushrooms and the giant parasols, and shares with them free gills and a partial veil, but its members are small, thin-fleshed and scaly, with white spore prints rather than the brown prints of Agaricus.

The genus is defined by a distinctive pattern of cap development. A young dapperling has a smooth, evenly coloured cap surface. As it expands, that surface layer cannot keep up and cracks apart into scales, leaving an unbroken disc at the centre where expansion is least and progressively smaller fragments toward the rim. In Lepiota cristata this produces the neat concentric arrangement that gives the species its scientific epithet, meaning crested.

It is also one of the more strongly scented small fungi. Fresh specimens carry a penetrating odour variously described as rubbery, of burnt hair or of household gas, quite unlike the pleasant smell of the field mushrooms, and detectable from a crushed cap without bringing it close to the face. Combined with its small size and reddish-brown scaling it is a fairly straightforward species to name.

Cap

2-5 cm across, at first a small dome or bell, then convex and finally flat with a persistent low umbo. The centre keeps a smooth, unbroken, reddish-brown to date-brown disc; outside this the brown surface layer fractures into small, neat, concentric rings of pointed scales on a white to cream ground, the scales becoming sparser and finer toward the rim. Very old or rain-washed caps can lose most of the outer scales, leaving a whitish cap with a brown eye.

Gills

Free from the stem and moderately crowded, soft, white to cream, sometimes discolouring faintly buff or pinkish in age. They are broad in the middle and taper at both ends, and the edges are minutely fringed.

Stipe

2-5 cm tall and 3-6 mm thick, slender, cylindrical or slightly swollen at the base, whitish above and flushing pinkish-brown to reddish-brown toward the base with age or handling. A small, thin, white ring sits high on the stem but is fragile and often collapses to a faint fibrillose zone or vanishes altogether.

Flesh & spore print

Flesh is thin and white, sometimes staining faintly reddish in the stem base. The odour is strong, sharp and rubbery. The spore print is white; under a microscope the spores are distinctively wedge- or bullet-shaped with a projecting spur, a feature shared with only a few relatives.

This is a fungus of nutrient-rich, disturbed soils. It fruits in troops and small groups on lawns, verges, path edges, in flower beds and mulched borders, along woodland rides, in hedge bottoms and in nettle-rich ground near habitation. It has no tree partner and appears equally in gardens and in deciduous woodland, favouring places where leaf litter, grass clippings or other organic matter accumulate in the topsoil.

Fruiting runs from midsummer through to late autumn, peaking with the first sustained autumn rains, and can begin earlier in wet summers. The species is common and widespread throughout Europe, across temperate Asia, and throughout North America, and has been recorded from introduced habitats in Australasia and southern Africa. It is one of the most frequently encountered small gilled fungi in urban and suburban settings.

The Stinking Dapperling is a saprotroph living on decaying plant material in the upper soil and litter layer. Its mycelium colonises fallen leaves, grass thatch, wood chip mulch and other humus, breaking down cellulose and lignin-poor plant tissue and releasing nutrients into the rooting zone of grasses and garden plants. It does not form mycorrhizal partnerships, which is why it is so unconstrained by tree species and so willing to fruit in artificial habitats.

Because it responds quickly to added organic matter, it is often among the first larger fungi to colonise new mulch, compost-enriched borders and recently landscaped ground, sometimes appearing in large troops within a season of soil disturbance. Repeated fruiting from the same patch of ground over several years indicates a persistent mycelial network working through the litter layer beneath the turf.

Lepiota clypeolaria is larger and paler, ochre-buff rather than reddish, and is separated at a glance by its stem, which is sheathed below the vanishing ring in a shaggy woolly white covering rather than being smooth. Lepiota castanea has a warmer chestnut cap with finer, more granular scaling and lacks the sharp rubbery odour. Echinoderma asperum is much larger and more robust, with erect pointed pyramidal spines rather than flat concentric scales.

Leucoagaricus leucothites can grow alongside it on lawns but is bigger, smooth and white with no brown scaling at all, and has a firm movable ring. Young Agaricus species may resemble a dapperling in outline but their gills turn pink and then chocolate-brown and they drop a dark brown spore print, whereas every Lepiota keeps white gills and prints white.