What You Should Know
Mycena haematopus is a species of fungus in the family Mycenaceae, of the order Agaricales. It is widespread and common in Europe and North America, and has also been collected in Japan and Venezuela.
This mushroom is characterized by a vinaceous-brown to pinkish-brown, conspicuously striate cap, often with a hairy margin when young and the tendency of the stipe to bleed a reddish juice when cut. It can be distinguished from other bleeding Mycenas by its preference for fruiting on rotting wood. There is also a form of this species with reddish, marginate gills.
Both cap and stalk exude a red latex where cut. The occurrence of this latex together with the wood substrate make this one of the more easily identifyable Mycena species. Mycena sanguinolenta (bleeding bonnet) is very similar but has dark red gill edges (margins) and occurs on the ground in leaf litter or beds of moss.
Other names: Bleeding Bellcap, Bleeding Mycena, Bleeding Fairy Helmet, Blood-foot Mushroom.
Mycena haematopus Mushroom Identification
Saprobic on the deadwood of hardwoods (rarely reported on the wood of conifers), usually on logs that are well decayed and without bark; growing in dense clusters (but sometimes growing alone or scattered); causing a white rot, according to Tom Volk (click the link below); spring through fall (and overwinter in warm climates); widely distributed and common in North America.
1-4 cm across; oval, becoming broadly conic, broadly bell-shaped, or nearly convex; the margin often with a tiny sterile portion, becoming tattered with age; dry and dusted with fine powder when young, becoming bald and tacky; sometimes shallowly lined or grooved; dark brownish red to reddish-brown at the center, lighter towards the margin; often fading to grayish pink or nearly whitish.
Narrowly attached to the stem; close or nearly distant; whitish, becoming grayish to purplish; often stained reddish-brown; edges colored like the faces.
4-8 cm long; 1-2 mm thick; equal; hollow; smooth or with pale reddish hairs; brownish red to reddish-brown or nearly purple; exuding a purplish red juice when crushed or broken.
Insubstantial; pallid or colored like the cap; exuding a purplish red juice when crushed or cut.
Odor and Taste
Odor not distinctive; taste mild or slightly bitter.
Mycena haematopus Glow
Both the mycelia and the fruit bodies of M. haematopus (both young and mature specimens) are reported to be bioluminescent. However, the luminescence is quite weak, and not visible to the dark-adapted eye; in one study, light emission was detectable only after 20 hours of exposure to X-ray film. Although the biochemical basis of bioluminescence in M. haematopus has not been scientifically investigated, in general, bioluminescence is caused by the action of luciferases, enzymes that produce light by the oxidation of a luciferin (a pigment).
The biological purpose of bioluminescence in fungi is not definitively known, although several hypotheses have been suggested: it may help attract insects to help with spore dispersal, it may be a by-product of other biochemical functions, or it may help deter heterotrophs that might consume the fungus.
Mycena haematopus Taxonomy and Etymology
This species was described in 1799 by Christiaan Hendrik Persoon, who called it Agaricus haematopus - a name subsequently sanctioned by Elias Magnus Fries in 1821; it was moved to the new genus Mycena by Paul Kummer in 1871.
Synonyms of Mycena haematopus include Agaricus haematopus Pers., Galactopus haematopus (Pers.) Earle, and Mycena haematopus var. marginata J. E. Lange.
The specific epithet haematopus comes from ancient Greek words haemato-, which means blood, and -pus, meaning foot (or leg) - a reference to the blood-like liquid which exudes from a cut or broken stems.
Above: These Burgundy-drop Bonnets have seen fruiting on the end of a log in Cambridgeshire, England during the 2013 British Mycological Society's Autumn Foray. It is always worth searching wood piles for fungi, and in particular, logs piled up in damp woodland. In the open, most of the fungi tend to emerge on the northern or eastern side rather than on the south and west where the afternoon sun dries the timber.
Mycena haematopus Uses
Several unique chemicals are produced by Mycena haematopus. The primary pigment is haematopodin B, which is so chemically sensitive (breaking down upon exposure to air and light) that its more stable breakdown product, haematopodin, was known before its eventual discovery and characterization in 2008. A chemical synthesis for haematopodin was reported in 1996.
Haematopodins are the first pyrroloquinoline alkaloids discovered in fungi; pyrroloquinolines combine the structures of pyrrole and quinoline, both heterocyclic aromatic organic compounds. Compounds of this type also occur in marine sponges and are attracting research interest due to various biological properties, such as cytotoxicity against tumor cell lines, and both antifungal and antimicrobial activities.
Additional alkaloid compounds in M. haematopus include the red pigments mycenarubins D, E and F. Before the discovery of these compounds, pyrroloquinoline alkaloids were considered to be rare in terrestrial sources.
Photo 1 - Author: Albarubescens (Creative Commons Attribution 4.0 International)
Photo 2 - Author: Patrick Harvey (pg_harvey) (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 3 - Author: Stu's Images (Creative Commons Attribution-Share Alike 4.0 International)
Photo 4 - Author: Dan Molter (shroomydan) (Creative Commons Attribution-Share Alike 3.0 Unported)