Felt Saddle Identification Guide

What you are looking at

Helvella macropus is an ascomycete, so nothing about it works like a gilled mushroom. What you find is a small shallow cup carried on a long slender stalk, standing among moss or leaf litter on a damp woodland bank. The whole thing is grey, matt and softly furry, and at a glance it resembles a miniature goblet made of felt. It is easy to walk past: the cup is often no wider than a fingernail and the colour matches wet leaf litter exactly.

The typical setting is shaded broadleaved or mixed woodland with moisture in the soil, especially the sides of paths and ditches, mossy banks, stream margins and old woodland where litter accumulates. Fruit bodies are usually solitary or in small scattered groups, appearing from summer into autumn, often earlier in the season than the large lobed saddle fungi.

Reading the cup

The apothecium, the cup, is 1 to 3 cm across and rarely reaches 4. It starts as a deep little bowl and expands to a saucer, then frequently becomes irregular: the margin waves, folds inward, splits, or lifts on two sides so that the whole disc takes on a saddle-like sag. That irregularity is normal and should not be treated as damage.

Two surfaces need separate examination. The upper or inner face is the fertile hymenium. It is smooth, matt to slightly greasy, and coloured mouse grey, grey-brown or brownish grey, darkening when wet and paling as it dries. There are no veins, ribs or wrinkles on it.

The outer or lower face is the character that names the species. Look at it with a hand lens and it is densely clothed in short grey hairs, giving a matt, minutely velvety, felted texture and a paler, greyer tone than the inside. The margin is usually fringed with the same hairs. If the outside is smooth, shining or scurfy rather than furry, you are looking at something else.

Reading the stalk

The stipe is 2 to 6 cm long and only 2 to 5 mm thick, which makes it look disproportionately long for the small cup and gives the species its name. It is cylindrical or very slightly tapering upward, solid or narrowly stuffed rather than chambered, and grey to grey-brown.

Run a finger down it. It is downy or minutely hairy along its entire length, matching the outside of the cup. Critically, it is round in section and completely smooth in outline: there are no longitudinal ribs, no branching veins and no deep pockets or lacunae. The base sits directly in soil or moss with a few pale hyphal threads, without a bulb, sac or disc.

Flesh and colour change

Cut a fruit body in half from the cup down through the stalk. The flesh is very thin, greyish and slightly waxy or rubbery, snapping cleanly rather than tearing. There is no latex, no gel layer and no milky juice. Nothing changes colour on cutting, bruising or drying, and there is no colour reaction when the specimen is handled. Absence of change is itself informative: a small grey cup fungus that blackens or blues on handling belongs elsewhere.

Odour is faint or absent. The texture is more useful than the smell.

Spores and how to take a deposit

A conventional spore print cannot be taken in the way it is taken from gills, because the spores are shot upward from asci on the exposed inner face rather than dropping from beneath a cap. There are two practical substitutes.

The first is a deposit. Place the fresh fruit body inside a small closed container with a glass slide or a piece of dark card held above the hymenium, or simply invert a clean slide over the cup, and leave it for an hour or two in a humid space. A mature specimen will fire spores upward and leave a faint whitish film. Breathing gently on the cup, or moving it from cool air into warm air, often triggers a visible puff of spores.

The second and better route is direct microscopy. Shave a sliver from the inner surface, mount it in water and look at the asci. Each contains eight spores. The spores of this species are the decisive character: they are fusiform, that is spindle shaped with drawn-out narrowed ends, large at roughly 20 to 27 by 10 to 13 microns, and each carries one big central oil drop with smaller droplets towards the tips. Most other saddle fungi have plainly ellipsoid spores, so a fusiform spore combined with a hairy grey exterior is conclusive.

Substrate and season

Fruit bodies grow directly from soil, from moss cushions and from buried woody debris in damp woodland. Both broadleaved and coniferous woods are used, and the fungus is frequently found on clay or loam banks where the surface litter is thin. Its trophic strategy is debated, with evidence pointing towards an ectomycorrhizal association with trees, so note the surrounding species when you record it. The season is summer to autumn, and fruiting follows steady rain rather than a single downpour.

Separating it from look-alikes

Helvella acetabulum is the most obvious contrast. It is much larger, forms a deep goblet rather than a saucer, and its stout stipe is heavily ribbed with branching veins that continue up onto the outside of the cup. Nothing about its stalk is smooth or slender.

Helvella corium is blackish inside and out, has a firmer, more regular cup with a short dark stalk, and favours damp sandy ground and dune slacks with creeping willow.

Helvella lacunosa and Helvella crispa are true saddles: their fertile part is lobed and convoluted rather than cup shaped, and their stipes are thick, deeply furrowed and internally chambered.

Helvella villosa is the genuinely difficult neighbour and is treated by some authors as inseparable. It tends to be smaller and paler with a shorter stalk, and reliable separation depends on spore measurement rather than field appearance.

Peziza species sit flat on the substrate with no real stalk and have smooth, often brittle, scurfy exteriors. Tarzetta species have a toothed or notched margin and only a short stalk-like base. Humaria hemisphaerica is sessile, with a whitish inner face and stiff brown hairs outside. In every case the combination of a long, slender, unribbed, downy grey stalk and a felted grey exterior is what marks out Helvella macropus.