Bleeding Bonnet Identification Guide

Getting Your Eye In

This is a small fungus and you will not find it by scanning. Bleeding Bonnet fruits in troops among moss, conifer needles and broadleaf litter, and the individual fruit bodies stand only 3-6 cm tall on stems no thicker than a coarse hair. The usual way to find it is to kneel down in a mossy patch of woodland floor in autumn, get your face close, and let the eye adjust to the scale. Once it does, a bank that looked empty resolves into dozens of tiny pinkish-brown parasols on dark wiry stems.

Bring a hand lens. Almost every character that matters here needs magnification, and two of them are destroyed if you handle the specimen roughly.

The Test That Names It

Before anything else, do the one test the common name refers to. Take a single fruit body between finger and thumb, snap the stipe cleanly near the middle, and watch the broken end. Within a few seconds a bead of dark red to blackish-red juice wells out. It is a small amount, so do it over a pale surface such as a fingernail or a sheet of white paper where you can see it clearly. Fresh, well-hydrated material bleeds readily; in a dry spell the reaction can be weak, so try several stems.

Reading the Cap

The cap is 0.5-1.5 cm across, occasionally a little more. Young caps are conical to bell-shaped, expanding to broadly conical or campanulate, sometimes with a small blunt umbo. The surface is smooth, moist and hygrophanous, and the margin is translucent-striate when damp, so that the lines of the gills show through the flesh right up towards the centre.

Colour is reddish-brown, pinkish-brown or greyish-brown, generally darker in the centre and paling towards the rim, and fading noticeably as the cap dries. Under a lens the whole surface is finely pruinose in very young material. The margin is often edged with the same reddish-brown tone as the gill edges, which is a supporting detail once you know to look for it.

Gills and Gill Edge

The gills are whitish to pale pinkish-grey, adnate or slightly ascending, moderately spaced and rather narrow, with a few shorter gills between the full ones. The character to look for with the lens is the edge: each gill is finished with a fine, dark reddish-brown to purplish-brown line. On a fresh specimen this is clear at 10x and gives the gill face a neatly ruled appearance.

Two dark-edged features on one fungus, the gill margin and the cap rim, plus a stem that bleeds red, are what make this species identifiable in the field despite its size.

Stipe and Base

The stipe is 2-6 cm long and only 0.5-1.5 mm thick, cylindrical, hollow, smooth or minutely pruinose above and finely hairy at the base. It is a similar reddish-brown to dark purple-brown, usually darker than the cap and darkest towards the base, and it is remarkably straight and wiry for such a delicate fungus. The base carries a small tuft of coarse whitish hairs or strigose fibrils that grip the moss or litter; pull rather than pinch when you collect, so those hairs come up with the specimen.

Flesh and Colour Change

The flesh is very thin, watery and pale reddish-brown. Colour change is the bleeding described above rather than an oxidation reaction: the dark red fluid is present in the stipe and is released mechanically. Cut material browns slowly as it dries but does not blue, green or blacken. There is no distinctive smell worth relying on.

Taking a Spore Print

A cap this small yields a faint print, so give it the best possible chance. Choose the largest fully expanded specimen you can find, cut the stipe flush with the gills, place the cap gill-side down on black glass or dark card, cover it with a small glass to hold moisture, and leave it overnight in a cool place. The deposit is white and may be no more than a delicate ghost of the gill pattern, which is exactly why a dark background matters. In iodine reagent the spores are amyloid, staining blue-grey, confirming the genus.

Substrate, Season and Setting

Bleeding Bonnet is a litter and moss decomposer. It fruits from conifer needle beds, fallen broadleaf litter, mossy banks, rotting twigs buried in the litter and mossy turf at woodland edges. It is not restricted to wood and generally is not found perched on stumps and logs the way some of its relatives are. It occurs from summer well into late autumn, often persisting after the larger woodland species have finished, and it is typically gregarious, with scattered troops over a wide area rather than tight clusters.

Damp, sheltered, mossy ground under conifers is the most productive habitat, but old broadleaf litter in a humid hollow will do just as well.

Separating the Look-Alikes on Morphology

Mycena haematopus is the other well-known bleeder and the main confusion. It is considerably larger, with caps 1-4 cm across, and it grows in tight clusters directly on dead broadleaf wood, especially stumps and fallen logs, rather than in litter. Its cap margin is characteristically scalloped or minutely toothed and paler than the disc, its latex is dark purplish-red, and its gill edges are not sharply outlined in dark red. Substrate plus size plus the toothed cap margin separates the two cleanly.

Mycena crocata also bleeds, but the juice is bright orange to saffron and stains the fingers and the fungus orange. It grows in beech litter and on buried twigs and has a paler, greyish cap on a longer stem.

Mycena galopus exudes white, milky juice from the stem rather than red, and although the dark form has a nearly blackish stipe, the white latex separates it instantly.

Mycena galericulata and other grey bonnets on wood are larger, tougher, greyer, and do not bleed at all.

Mycena filopes and similar small litter bonnets are grey-brown, do not bleed, and lack the dark gill edge.

If a small pinkish-brown bonnet in litter bleeds dark red and has reddish-brown gill edges under a lens, no other common species matches on those two points together.

Field Sequence

Kneel in mossy litter; look for troops of tiny reddish-brown conical caps with translucent-striate margins; snap a stem and watch for dark red juice; check gill edges at 10x for a fine reddish-brown line; confirm the wiry dark stipe with a hairy base; take a white spore print from the largest cap available.