Trooping Funnel Identification Guide

First impression and the setting

Trooping Funnel is a late season spectacle rather than a subtle find. Walk a woodland ride, a hedge bank, a chalk scrub margin or the rough grass at the edge of a beech wood in late October or November and you may meet an arc of large, pale, long stemmed mushrooms standing well clear of the grass, sometimes a dozen or more in a curve or a complete ring several metres across. The English name records the habit exactly: they troop.

The silhouette is what registers first. This is a tall mushroom, unusually so for something with a funnel shaped cap, standing 10 to 20 cm high with a stout stem, so it reads more like a small pale trumpet on a post than a squat woodland cap. The colour is a warm buff, leather or pale tan, sometimes with a faint pinkish or ochre wash, and old specimens weather cream and slightly stained.

Reading the cap

Young caps are convex with a strongly inrolled, finely downy margin and, importantly, a low central umbo. As the cap expands to 8 to 20 cm, occasionally more, it becomes broadly depressed and finally deeply funnel shaped, but that umbo usually persists as a small blunt boss standing in the middle of the depression. Seen from the side, the profile is a shallow dish with a nipple in the base. That detail is worth hunting for, since it is one of the quickest separations from the taller stemmed cousins and the whiter relatives.

The surface is dry, matt and finely felted rather than smooth or greasy, and it may darken and look slightly greasy only when thoroughly soaked. In maturity the margin becomes wavy, sometimes split, and often rises above the cap centre. The flesh of the cap is thick over the centre, thinning towards the rim.

Gills, stipe and base

The gills are strongly decurrent, running well down onto the stem in long tapering lines, and they are crowded, narrow and whitish to pale cream, ageing buff. Interleaved short gills are numerous. Look at where the gill meets the cap flesh: in this group the gill trama separates fairly readily from the cap flesh, which is a useful habit to test with a fingernail.

The stipe is 6 to 15 cm long and 2 to 4 cm thick, firm and fibrous, cream to pale buff, longitudinally fibrillose, and typically club shaped, swelling towards the base. There is no ring and no volva. At the very base sits a conspicuous pad of white mycelial felt binding leaf litter, grass roots and soil into a plug that comes up with the mushroom. Lifting one whole is worth the trouble, because that basal felt and the swollen stem together are part of the picture.

Flesh, odour and colour change

Cut a fruit body from cap to base. The flesh is white, thick and firm, dry rather than watery, and does not change colour when cut or bruised beyond a faint cream discoloration in age. Firmness is characteristic: these are heavy, solid mushrooms that survive frost and can stand for two or three weeks.

Fresh specimens carry a faint, pleasant, sweetish smell, often described as slightly aromatic or almond like. It is subtle, so crush a piece of cap flesh and smell it immediately.

Taking and reading the spore print

A large cap deposits generously. Cut the stem off flush, set the cap gill side down on dark card, or half on white and half on dark, and cover with a bowl for four to six hours. The print is white to very pale cream. Do not expect any pink, buff or brown tint; if you get one, you are dealing with a different genus entirely and the identification collapses.

Under a microscope the spores are smooth, broadly ellipsoid to tear shaped, colourless, and they do not stain blue grey in iodine. That non amyloid reaction is a genuinely decisive check against the big white funnels of the genus Leucopaxillus, whose spores are ornamented and turn blue grey in iodine.

Substrate, ecology and season

This is a litter decomposer. Its mycelium spreads outward through leaf litter, grass thatch and the upper soil in a slowly expanding circle, exhausting nutrients behind the advancing front, which is why it fruits in arcs and rings and why the same ring reappears in the same place year after year, a little larger each time.

Habitat is edge habitat: woodland rides and clearings, hedge banks, scrubby grassland, chalk downland margins, verges under lime, beech and oak, and old parkland. The season is late, mostly from October to December, extending into January in mild spells. It is one of the last large mushrooms standing.

Separating the closest look-alikes

Common Funnel, Infundibulicybe gibba, is the same shape in miniature. Its cap is 4 to 8 cm, pinkish tan, thin fleshed, and it stands on a slender stem only 5 to 8 mm thick. It fruits earlier, from summer into autumn, in woodland leaf litter, and never has the stout club shaped stem or the great trooping rings.

Clouded Agaric, Clitocybe nebularis, shares the late season and the ring forming habit and often grows nearby. Its cap is grey to grey brown with a pale bloom, convex to shallowly depressed but never deeply funnel shaped and never umbonate, its crowded pale gills are only shortly decurrent, and it has a strong, distinctly sweetish and slightly sour smell rather than a faint almond note.

Giant Funnel, Leucopaxillus giganteus, is the trickiest. It forms very large rings in pasture, has a broad white to cream cap that can exceed 25 cm, and it too is funnel shaped. Look for a persistently strongly inrolled margin, an absence of any central umbo, very crowded narrow gills that peel easily from the cap, a shorter and thicker stem in proportion to the cap, and a distinctly different smell. Microscopically its ornamented, iodine positive spores settle the matter.

Tawny Funnel, Paralepista flaccida, is smaller, warm rusty orange to tan, with crowded decurrent gills and a thin stem, growing in leaf litter and often in dense troops. Its spores are minutely warted, unlike the smooth spores here.

Field Blewit relatives such as Lepista irina are pale and grow in rings on similar ground but have sinuate rather than decurrent gills, a strong sweet smell, and a pale pinkish spore deposit.

Livid Pinkgill, Entoloma sinuatum, is another large pale mushroom of woodland edges on calcareous soil. Its cap is convex with a low umbo but never funnel shaped, its gills are sinuate and turn pink with maturity, and its print is salmon pink, so a print resolves it in a few hours.

False Chanterelle, Hygrophoropsis aurantiaca, is small, thin fleshed and orange, with repeatedly forked decurrent gills, and belongs to conifer litter and woodchip rather than to grassy rings.