Key to the European members of sect. Cinerellae

Mycena sect. Cinerellae Singer ex Maas Geest. is a fairly heterogenous section although it comprises only ten species. Six of these are little known or only known from the type locality. The ten species are Mycena aleuriosma Favre, M. cinerella (P. Karst) P. Karst., M. clavicularis (Fr.) Gillet, M. concolor (J. E. Lange) Kühner, M. inopinata Maas Geest., M. madronicola A. H. Sm., M. pseudopicta (J. E. Lange) Kühner, M. subconcolor A. H. Sm., M. subgrisea (Peck) Maas Geest., and M. winterhoffii Maas Geest. Some mycologists have also recognized Mycena cineroides Hintikka as a separate species. Maas Geesteranus (1991: 386), however, stated that it must be considered as a synonym of M. cinerella. I am inclined to follow his view.

The key below has been taken from Maas Geesteranus (1986 b) and slightly modified by me. I have included all the known species from the Northern Hemisphere. The American species have been marked with a yellow background.

A taxon collected by me in 1995 does not fit into any of the known species. It would key out between 4-spored Mycena madronicola and M. cinerella. The taxon is described and discussed here.

1. Basidia 2-spored
  2. Basidia clamped
    3. lamellae 11-14 reaching the stipe, spores 10.8-11.6 x 7.1-8.1 µm: Mycena winterhoffii
    3. lamellae 14-20 reaching the stipe, spores 7.6-9.0 x 4.9-5.8 µm, on bark of old madroña trees. Only known from Oregon, United States: Mycena madronicola
  2. Basidia without clamps
    4. Odour farinaceous. Cheilocystidia with short and comparatively rather fine excrescences: Mycena cinerella
    4. Odour none or occasionally somewhat raphanoid. Cheilocystidia with long and often very coarse excrescences: Mycena pseudopicta
1. Basidia 4-spored
  5. Cheilocystidia with generally numerous, evenly spaced, narrow excrescences
    6. Stipe glutinous to viscous when wet. Associated exclusively with coniferous trees: Mycena clavicularis
    6. Stipe dry. Only known from the type which was found on decayed wood of Betula lutea. United States: Mycena subgrisea
  5. Cheilocystidia with generally fairly few, unevenly spaced, usually irregularly shaped, more or less branched and coarse excrescences
    7. Spores 2.5-3.5 µm wide. Lamellae 14-16 reaching the stipe. Odour distinctly farinaceous when cut. Growing on fallen spruce needles. Only known from the type locality, Switzerland: Mycena aleuriosma
    7. Differently characterized.
      8. Lamellae 10-11 reaching the stipe. Spores up to 4 µm broad. Growing in wet places, not on fallen conifer needles. United States, unsufficiently known: Mycena inopinata
      8. Lamellae 13-27 reaching the stipe. Spores 4-6 µm broad
        9. Odour farinaceous when cut
          10. Colour of the pileus with a pronounced brown component. Corticolous on madroña trees. Known only from Oregon, United States: Mycena madronicola
          10. Colour of the pileus darker or more grey-brown. Not corticolous: Mycena cinerella
        9. Odour none or indistinctive
          11. Spores up to 5.2 µm broad, subcylindrical. Lamellae ascending to subarcuate. Cheilocystidia covered with comparatively narrow excrescences: Mycena concolor
          11. Spores 5-7 µm broad, fairly broadly pip-shaped. Lamellae subhorizontal. Cheilocystidia covered with broad and strikingly coarse excrescences. Known from the type locality in the United States and from Greenland: Mycena subconcolor



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