Mycena purpureofusca

Description

Mycena purpureofusca is a species of agaric fungus in the family Mycenaceae. It is characterized by a purple-brown, bell-shaped cap, vinaceous-purple, marginate gills, and non-bleeding stipe. Growing on decaying coniferous wood. Often found at the base of Picea or Pinus.

This mushroom contains a laccase enzyme that has been investigated scientifically for its potential to detoxify recalcitrant industrial dyes used in textile dyeing and printing processes. Laccases are widely used in biotechnology and industry due to their ability to break down various recalcitrant compounds.

Common names: Purple Edge Bonnet.

Mushroom Identification

1. Cap

   The cap is conical to bell-shaped, flattening in age, and reaches a diameter of 0.5–2.5 cm (0.2–1.0 in). The cap margin is usually bent inwards initially. The cap surface is initially covered with tiny white hairs but later becomes smooth. It is slightly hygrophanous, and when moist, is slightly translucent, so that the outline of the gills underneath is apparent. Its color is dark purple in the center, fading to pale lilac at the margins; older specimens are purplish-gray.

2. Flesh

   The flesh is thin and pliant, with a texture similar to cartilage. It is initially purplish-gray, becoming pale lilac to white in age.

3. Odor and Taste

   Not distinctive.

4. Gills

   The narrow gills have an ascending attachment to the stipe and are narrowly adnate. They are somewhat closely spaced, with pallid to grayish face color and dark grayish purple edges that are sometimes fringed.

5. Stipe

   The tubular stipe measures 3–10 cm (1.2–3.9 in) long by 1–3 mm thick. It is tough and cartilaginous, and its base it covered with white hairs. Overall, its color is that of the cap or paler, and often paler near the top.

6. Spores

   Spores are broadly ellipsoid in shape, amyloid, and have dimensions of either 8–10 by 6–7 µm or 10–14 by 6.7–8.5 µm depending on whether they originated from four-or two-spored basidia (spore-bearing cells), respectively. There are abundant cheilocystidia on the gill edges. They measure 30–50 by 7–12 µm, and are fusoid-ventricose, with tips that are broadly rounded. They are filled with a purplish sap and have granular contents. The cap tissue comprises a well-differentiated cuticle, a distinct hypoderm, and a filamentous tramal body. Clamp connections in the hyphae are rare or absent.

7. Spore Print

   White.

8. Habitat and Distribution

   The fruit bodies of Mycena purpureofusca grow singly or in clusters on the decaying wood of conifers, particularly spruce, pine, and Douglas-fir. It is commonly found on decaying pine cones. In a European study, the fungus was found growing on logs in a state of decay where the wood was mostly hard, with most of the bark left, to wood that had decayed to the point that it was mostly soft throughout. In North America, the fungus has been recorded in North Carolina, Tennessee, New York, Michigan, Montana, Idaho, Washington, Oregon, California, Virginia, and South Dakota. In Canada, it has been found in Ontario. Smith noted that collections from Michigan are likely to be found on old hemlock knots lying in the soil, where it usually fruits singly; it tends to grow in clusters on logs and stumps. In Europe, it has been recorded from Britain, Scotland, the Czech Republic, Poland, Germany, and Turkey. In the UK, the fungus is commonly found in Caledonian pine woods, and it is considered an indicator species for that habitat type.

Look-Alikes

1. Mycena haematopus

   Which can be distinguished by a lignicolous habit (but rarely cones), stipe that bleeds a reddish juice, and a cap with a scalloped margin.

2. Mycena californiensis

   Is found in oak duff, has a brighter colored cap (orange-brown), a stipe that bleeds a reddish juice, and an oak duff habit. Formerly known locally as M. sanguinolenta.

3. Mycena elegantula

   A name that has been used in the past for cone-inhabiting Mycenas is a synonym of Mycena elegantula.

4. Mycena lux-coeli

   The bioluminescent mushroom is another allied species, but it has smaller spores (8.5–12 by 6.5–9 µm) and its cystidia is more lobed.

5. Mycena rubromarginata

   Could be distinguished by its darker color and "non-hygrophanous striate pileus.

History

The species was first described as Agaricus purpureofuscus by American mycologist Charles Horton Peck in 1885. The type collection was made in Caroga, New York, from a moss-covered trunk of spruce. Pier Andrea Saccardo transferred it to Mycena in 1887, giving it the name by which it is currently known. William Alphonso Murrill moved it to Prunulus in 1916, but this genus has since been subsumed in Mycena. In 1879, Petter Karsten described a collection made in Scandinavia as Mycena atromarginata var. fuscopurpurea, but Rudolph Arnold Maas Geesteranus later placed this in synonymy with M. purpureofusca. Another synonym, according to Maas Geesteranus, is Mycena sulcata, described by Josef Velenovský in 1920 from Czechoslovakia.

Alexander H. Smith classified the species in section Calodontes, subsection Ciliatae of Mycena in his 1947 monograph on North American Mycena. Rolf Singer put it in the section Rubromarginata in his 1986 The Agaricales in Modern Taxonomy, a group characterized by having distinct red marginate gills.

The specific epithet purpureofuscus combines the Latin words purpur (purple) and fusco (dark or dusky).

Synonyms

1. Mycena atromarginata var. fuscopurpurea P.Karst. (1879)

2. Agaricus purpureofuscus Peck (1885)

3. Prunulus purpureofuscus (Peck) Murrill (1916)

4. Mycena sulcata Velen. (1920)

Photo sources:

Photo 1 - Author: Oregon Caves from Cave Junction, USA (CC BY-SA 2.0)

Photo 2 - Author: Oregon Caves from Cave Junction, USA (CC BY-SA 2.0)

Photo 3 - Author: Richard Sullivan (enchplant) (CC BY-SA 3.0)