A key to Norwegian Mycenas

Key to the European members
of section Fragilipedes

Sect. Fragilipedes (Fr.) Quél. is the largest section in Mycena. Many of the species in the section have only been found in the United States and many are known only by the type collection. Some of the European species are also insufficiently known, and the recent years a nµmber of new species have been proposed, of which quite a few have been collected only once.

Some of the new species are critical and will perhaps prove not to be good species, but probably there are still new species to be discovered too. In the future the nµmber of species in this already so large section will increase. No wonder it is a heteregenous and difficult section. I know less than half of the species accomodated in sect. Fragilipedes, and the key below do not cover all the species that have been recorded in Europe. Hopefully some of the new species in the future will be found outside the type area too.

As far as I know 64 species of sect. Fragilipedes have been recorded in Europe (March 2009). Of these as many as 40 have been proposed after Maas Geesteranus published his key to the section (Maas Geesteranus, 1988).

Robich (2006) provided a revised key to the section. The species of the section are as follows (species proposed after 1988 in red):

M. abramsii (Murrill) Murrill, M. aculeata Maas Geest., M. aetites (Fr.) Quél., M. albido-rosea Robich, M. algeriensis Maire , M. alnetorum Favre, M. aronsenii Maas Geest., M. atrovinosa Robich, M. austera Aronsen, M. bambusae-pygmaeae Robich, M. caliginosa Maas Geest. & Enderle, M. cinereopileata Robich, M. citrinomarginata Gillet, M. corrugans Maas Geest., M. cretata Aronsen, M. cyrnea Maas Geest., M. erminea Maas Geest., M. flocculina (Kalamees) Villarreal, M. fragillima A.H. Sm., M. fuligineipapillata Robich, M. gilvipes Villarreal, Heykoop & Maas Geest., M. gladiocystis Esteve-Rav. & A. Ortega, M. handkeana Miersch, Penke & Maas Geest., M. hausknechtii Maas Geest., M. laevigata (Lasch) Gillet, M. laevigatoides Maas Geest., M. leptocephala (Pers.: Fr.) Gillet, M. lignivora Maas Geest., M. lutea Bres., M. maurella Robich, M. mitis Maas Geest., M. murina (Murrill) Murrill, M. muscicola Robich, M. nigroalba Métrod ex Maas Geest., M. niveipes (Murrill) Murrill, M. obtecta Maas Geest., M. olivaceoflava Villarreal, Heykoop & Maas Geest., M. parca Aronsen, M. parvoaquosipes Robich, M. pilosella Maas Geest., M. polygramma (Bull.) Gray, M. pruinatipes Robich, M. pseudoinclinata A.H. Sm., M. pullicaulis Robich, M. rubidofusca Villarreal, Heykoop & Maas Geest., M. saturejophila Vila & F. Caballero, M. scirpicola Villarreal, Heykoop, Esteve-Rav. & Maas Geest., M. silvae-nigrae Maas Geest. & Schwöbel, Mycena spinulosipes Robich, M. stipata Maas Geest. & Schwöbel, M. strobilicola Favre & Kühner, M. subcana A.H. Sm., M. subexcisa (P. Karst.) Sacc., M. subtilis Robich, M. tephrophylla Maas Geest. & Schwöbel, M. tristis Maas Geest., M. ustalis Aronsen & Maas Geest., M. valida Maas Geest. & Münzmay, M. verna Maas Geest., M. vicina Villarreal, Heykoop & Maas Geest., M. villicaulis Maas Geest., M. viridimarginata P. Karst., M. vitilis (Fr.) Quél, M. zephirus (Fr) P. Kumm.

KEY 1.

Hyphae of the pileipellis and the stipe cortex smooth.

1. Hyphae of the pileipellis smooth (in some species with very few, scattered excrescences)

2. Hyphae of the cortical layer of the stipe smooth

3. Pleurocystidia present

4. Spores less than 6 µm broad

5. Pileus white, pale pink. Stipe white, yellow-white below: M. albido-rosea

5. Pileus with darker colours

6. Clamp connections absent. Growing on fallen Picea cones in the spring: M. strobilicola

6. Clamp connections present

7. Pileus dark brown to blackish

8. Cheilocystidia 57-103 µm long, strongly protruding, fusiform or sublageniform. Growing on decaying wood of deciduous trees: M. algeriensis

8. Cheilocystidia 20-60 µm long, clavate to fusiform. Terrestrial: M. ustalis (4-spored)

7. Pileus grey-brown to cream brown. Odour strongly of chloride. Cheilocystidia 27-40 µm long, subcylindrical, utriform or clavate. Spores 7.3-9.0 x 4.6-5.4 µm: M. caliginosa

4. Spores broader than 6 µm

9. Pileus dark brown to blackish

10. Cheilocystidia 57-103 µm long, strongly protruding, fusiform or sublageniform. Growing on decaying wood of deciduous trees: M. algeriensis

10. Cheilocystidia 20-60 µm long, clavate to fusiform. Terrestrial: M. ustalis (2-spored)

9. Pileus paler grey-brown

11. Cheilocystidia 40-110 x 9-22 µm, fusiform, lageniform, subcylindrical or clavate, smooth. On decaying wood of deciduous trees.: M. niveipes

11. Cheilocystidia 25-45 x 4-6 µm, sinuous, flexuous, smooth to coarsely furcate. Terrestrial: M. maurella

3. Pleurocystidia absent

12. Pileus white, growing cespitose on decaying wood of conifers: M. laevigata

12. Pileus differently coloured.

13. Hyphae of the pileipellis and the cortical layer of the stipe embedded in gelatinous matter. Pileus dark sepia brown. Cespitose on coniferous wood: M. stipata

13. Hyphae og the pileipellis and the cortical layer of the stipe not gelatinized. Occuring in the spring.

14. Pileus pale dingy pinkish brown, lamellae pink, stipe pale brownish white with a slight yellowish tint. On decayed wood of Fagus: M. lignivora

14. Pileus vinous purplish brown, lamellae whitish, stipe ochraceous yellow. On decayed wood of deciduous tree. : M. aculeata

14. Pileus at first blackish brown, then sepia brown, reddish brown to grey brown, lamellae grey, stipe slightly paler than the pileus. On decaying stµmp of Pinus: M. tephrophylla

2. Hyphae of the cortical layer of the stipe with excrescences: Key 2

1. Hyphae of the pileipellis diverticulate: Key 3

KEY 2.

Hyphae of the pileipellis smooth. Hyphae of the cortical layer of the stipe with excrescences.

15. Hyphae of the pileipellis embedded in gelatinous matter

16. Pileus sepia brown, odour nitrous, hyphae of the stipe cortex smooth or with very scattered excrescences, spores 9.2-11.6 x 5.4-6.3 µm: M. stipata

16. Pileus white to ochraceous, odour indistinctive, hyphae of the stipe cortex sparsely diverticulate, spores 6.3-9.0 x 3.8-4.7 µm: M. laevigata

15. Hyphae of the pileipellis not embedded in gelatinous matter

17. Pileus white or beige to pale brownish, soon stained with reddish brown spots. Spores almost cylindrical, cheilocystidia fusiform, clavate, subcylindrical, smooth or with finger-like excrescences, pleurocystidia usually present. Terrestrial: M. zephirus

17. Pileus fuscous to dark watery grey with whitish margin, not stained with reddish brown spots. Spores broadly pip-shaped, cheilocystidia more or less clavate, covered with irregular, coarse excrescences, pleurocystidia absent. On decaying wood: M. pseudoinclinata

KEY 3.

Hyphae of the pileipellis diverticulate. Hyphae of the cortical layer of the stipe smooth. Spores broader than 6 µm.

18. Hyphae of the cortical layer of the stipe smooth

19. Spores broader than 6 µm

20. Pleurocystidia present

21. Basidia 2-spored, clampless

22. stipe yellow to ochraceous. Cheilocystidia not flexuous: M. lutea

22. stipe brownish. Cheilocystidia flexuous: M. maurella

21. Basidia 4-spored, clamped

23. Pileus and stipe greyish. Cheilocystidia not flexuous: M. murina

23. Pileus and stipe fairly dark brown. Odour alcaline or chlorine. Cheilocystidia flexuous: M. maurella

20. Pleurocystidia absent

24. More than 25 lamellae reaching the stipe. Spores broadly pip-shaped.

25. Pileus almost blackish. Stipe fragile. Cheilocystidia clavate, smooth or covered with finger-like excrescences. Hyphae of the stipe cortex smooth or covered with small warts: M. tristis

25. Pileus grey-brown to dark sepia brown. Stipe rigid, cartilaginous. Cheilocystidia fusiform, lageniform, utriform, subcylindrical or irregularly shaped, smooth or with a few coarse excrescences: M. polygramma

24. Less than 25 lamellae reaching the stipe

26. Hyphae of the pileipellis tending to form dense masses and become gelatinized

27. Pileus dark reddish brown to dark reddish grey, the centre black-brown. Hyphae of the stipe cortex embedded in gelatinous matter: M. rubidofusca

27. Pileus differently coloured

28. Pileus grey brown to sepia brown. Stipe often grooved lengthwise. Hyphae clamped. Hyphae of the stipe cortex not embedded in gelatinous matter: M. polygramma

28. Pileus grey brown to sepia brown, sometimes paler to almost whitish. Stipe smooth, lubricous to almost viscid wen wet, shiny when dry. Hyphae generally clampless. Stipe cortex embedded in gelatinous matter: M. vitilis

26. Hyphae of the pileipellis not gelatinized

29. Pileus almost black under a white-pruinose covering. Stipe dark brown. Lamellae almost free, white with a pinkish sheen: M. nigroalba

29. Pileus and lamellae differently coloured

30. Lamellar edge often olive green or brownish. Excrescences of the hyphae of the pileipellis inflated or with inflated parts: M. viridimarginata

30. Lamellae whitish with some pinkish tint, becoming spotted with vinaceous stains, the edge concolorous. Excrescences of the hyphae of the pileipellis much branched 2-45 µm long: M. obtecta

19. Spores less than 6 µm broad: Key 4

18. Hyphae of the cortical layer diverticulate: Key 5

KEY 4.

Hyphae of the pileipellis diverticulate. Hyphae of the cortical layer of the stipe smooth. Spores less than 6 µm broad.

31. Pileus white, whitish or with yellow colours

32. Pileus yellow or yellowish. Lamellar edge yellow: M. citrinomarginata

32. Pileus white to whitish

33. Pileus pure white, then very pale creamy pink or pale cream. Odour nitrous. Caulocystidia clavate, smooth or with a few coarse to very coarse excrescences: M. erminea

33. Pileus white with a slight yellowish tint. Odour alcaline. Caulocystidia slender, hair-like up to more than100 µm long: M. pilosella

31. Pileus differently coloured

34. Caulocystidia slender, hair-like with slightly thickened walls at the base, up to 300 µm long: M. scirpicola

34. Caulocystidia strikingly inflated, up to 20 µm wide

35. Pileus and stipe fairly pale grey, with no brown colours: M. fragillima

35. Pileus and stipe darker grey, brownish to grey-brown: M. leptocephala

34. Caulocystidia differently shaped, if present.

36. Pileus and stipe paler or darker grey, without any brown colours (M. parca with stipe brown-grey below).

37. Cheilocystidia almost cylindrical, more rarely subclavate. Pileus greyish black, becoming ash grey: M. subexcisa

37. Cheilocystidia fusiform. Pileus dark grey with almost black centre. Hyphae clampless. Terminal cells of the hyphae of the pileipellis conspiculously inflated, frequently covered with coarse excrescences: M. austera

37. Cheilocystidia lageniform. Pileus dark to pale grey. Terminal cells of stipe cortex slender-clavate, smooth: M. parca

37. Cheilocystidia variously shaped, smooth or with finger-like excrescences. Hyphae of the stipe cortex smooth or sparsely diverticulate. Pileus grey with a slight bluish tint, pallescent, becoming ash grey to whitish grey: M. murina

36. Pileus and stipe brown or with violet or vinaceous tint

38. Cheilocystidia flexuous, 3-5 µm wide. Pileus greyish, grey with brown tint, centre sooty grey: M. fuligineipapillata

38. Cheilocystidia fusiform, lageniform, clavate, broader than 5 µm.

39. Pileus brown-black with vinaceous or violaceous tints. Cheilocystidia fusiform with rounded apex, clavate, 50-85 x 8-16 µm: M. atrovinosa

39. Pileus sepia brown with pale dingy pinkish margin, becoming dingy pinkish at the centre on frying out. Cheilocystidia fusiform to subcylindrical, 40-70 x 11.5-15 µm. Hyphae of the stipe cortex sparsely diverticulate, but often seemingly smooth: M. cyrnea

39. Pileus not with vinaceous, violaceous or pinkish tints.

40. Lamellae reaching the stipe 28-33. Pileus beige-brownish, 15-30 mm across. Odour weakly alcaline. Occuring in the spring: M. verna

40. Lamellae reaching the stipe 16-18. Pileus grey-brown, 8-10 mm across. Hyphae of the stipe cortex sparsely covered with simple to furcate, curved to more or less coiled excrescences: M. aronsenii

40. Lamellae reaching the stipe 17-20. Pileus warm beige-brown, 20-40 mm across. Odour nitrous. Hyphae of the stipe cortex embedded in gelatinous matter: M. valida

KEY 5.

Hyphae of the pileipellis diverticulate. Hyphae of the cortical layer of the stipe diverticulate.

41. Hyphae of the cortical layer of the stipe embedded in gelatinous matter

42. Pleurocystidia present

43. Pileus 20-40 mm across, beige-brown. Stipe fragile, watery horn grey, turning reddish brown from the base. Lamellae free, white to greyish white, becoming flushed with pink: M. valida

43. Pileus up to 35 mm across, dark brown, blackish grey to grey-brown or grey. Stipe fragile, brown, grey-brown or greyish. Lamellae narrowly adnate to adnate, dark grey to grey-brown: M. aetites

43. Pileus c. 20 mm across, greyish blavk, becoming ash grey. Stipe brittle, ash grey, pallescent. Lamellae narrowly adnate, decurrent with a tooth, white: M. subexcisa

42. Pleurocystidia absent

44. Spores broader than 6 µm

45. Pileus 5-11 mm across, white to cream. Lamellae 9-11 reaching the stipe. Basidia 2(-3)-spored. Cheilocystidia covered with coarse, simple to branched, curved to flexuous excrescences. Spores 12.5-16.1 x 7.2-9.4 µm: M corrugans

45. Pileus 10-14 mm across, dark reddish brown to reddish grey. Lamellae 18-20 reaching the stipe. Basidia 4-spored. Cheilocystidia fusiform, apically divided into two or more necks. Spores 8.5-10.5 x 6.5-8 µm: M. rubidofusca

44. Spores less than 6 µm broad

46. Pileus up to 5 mm across, very pale pink. Stipe very pale pink. Growing on fallen leaves of Quercus: M. mitis

46. Pileus up to 30 mm across, sepia brown. Stipe brown or with an ochraceous tint. Growing on coniferous wood: M. stipata

41. Hyphae of the cortical layer of the stipe not embedded in gelatinous matter

47. Pleurocystidia present

48. Basidia 2(-3)-spored, clampless

49. Pileus yellowish red-brown, stipe yellow to ochraceous. Odour absent: M. lutea

49. Pileus black-brown to sepia brown. Stipe brownish. Odour nitrous. Occuring on coniferous wood in the spring: M. silvae-nigrae

48. Basidia 4-spored, clamped.

49. Pileus very dark, brown-black, bluish black, dark grey

50. Pileus black, brown-black to bluish black. Cheilocystidia 18-25 µm long, fusiform, clamped: M. hausknechtii

50. Pileus dark grey with almost black centre. Cheilocystidia 50-103 µm long, fusiform, clampless: M. austera

50. Pileus dark grey, fading to ash grey. Cheilocystidia 19-42 µm long, fusiform, lageniform, clamped: M. subcana

49. Pileus not so dark, or then more brownish

51. Stipe greyish brown, blackening when drying, covered with long caulocystidia up to 300 µm long: M. scirpicola

51. Not these characters

52. Lamellae less than 20 reaching the stipe

53. Stipe with yellowish tints

54. Pileus dark grey to olive grey, without pink tinge. Cheilocystidia 80-110 µm. Hyphae of the stipitipellis densely diverticulate: M. gilvipes

54. Pileus sepia brown with pinkish tinge at the centre and the margin. Cheilocystidia 40-70 µm. Hyphae of the stipitipellis very sparsely diverticulate: M. cyrnea

53. Stipe without yellowish tints

55. Pileus up to 35 mm across, dark brown to greyish. Spores 8.5-10.7 x 5.5-7.1 µm. Hyphae of the pileipellis tending to form dense masses and becoming gelatinized: M. aetites

55. Pileus 8-10 mm across, grey-brown. Spores 7.6-8.2 x 4.9-5.5 µm. Hyphae of the pileipellis not gelatinizing: M. aronsenii

52. Lamellae more than 20 reaching the stipe

56. Basidia 2(-3)-spored, clampless. Growing on coniferous wood in the spring: M. silvae-nigrae

56. Basidia 4-spored, clamped.

57. Terminal cells of stipitipellis up to 72 µm long, covered with few or nµmerous excrescences. Cheilocystidia up to 92 µm long: M. vicina

57. Terminal cells of stipitipellis shorter and less conspicuous, if present. Cheilocystidia shorter.

58. Pileus and stipe greyish without any brown tinges

59. Pileus greyish black, becoming ash grey. Stipe brittle. Cheilocystidia cylindrical: M. subexcisa

59. Pileus grey with a slight bluish tint, becoming ash grey to whitish grey. Stipe fragile. Cheilocystidia variously shaped, smooth or with finger-like excrescences: M. murina

58. Pileus and stipe more or less with brownish tints

60. Spores elongated to cylindrical. Cheilocystidia generally apically drawn into a slender neck. Stipe, when fresh, exuding a watery fluid when incised: M. abramsii

60. Spores pip-shaped. Cheilocystidia apically drawn into a simple or furcate neck, or with relatively coarse excrescences. Growing in grassland: M. aetites

47. Pleurocystidia absent Key 6.

KEY 6.

Hyphae of the pileipellis diverticulate. Hyphae of the cortical layer of the stipe diverticulate and not gelatinized. Pleurocystidia absent.

61. Hyphae of the cortical layer of the stipe covered with thin, smooth "hairs" up to 300 µm long.

62. Hairs thick-walled. Pileus light grey-brown, paler to whitish towards the margin. Cheilocystidia 22.5-34 µm long, clavate, subcylindrical or subfusiform, apically drawn into a slender neck: M. villicaulis

62. Hairs thin-walled.

63. Hyphae of the stipe cortex smooth or with some isolated thick excrescence. Caulocystidia thin-walled but with slightly thickened walls at the base. Stipe greyish brown, blackening from the base when drying: M. scirpicola

63. Hyphae of the stipe cortex smooth or covered with a few excrescences. Caulocystidia thin-walled, slender, simple to somewhat branched. Stipe watery greyish white: M. pilosella

61. Hyphae of the cortical layer of the stipe not covered with hairs.

64. Pileus white, yellowish, or olivaceous.

65. Pileus white

66. Stipe fragile, watery grey or violet-grey below. Hyphae of the pileipellis not gelatinizing: M. laevigatoides

66. Stipe cartilaginous-brittle, white. Hyphae of the pileipellis generally gelatinized: M. polygramma f. candida

65. Pileus yellowish or olivaceous

67. Pileus and stipe olivaceous-yellow. Spores 9.5-11.5 x 5.5-7 µm. Clampless. Caulocystidia up to 20 µm wide.

67. Pileus yellowish red-brown. Stipe yellow to ochraceous. Spores 7-8 x 4-5 µm. Clamped: M. lutea (4-spored form)

67. Pileus and stipe yellowish. Lamellae with yellow edge. Spores 9.2-12.0(-14.4) x 4.6-5.6(-6.4) µm. Clamped: M. citrinomarginata

64. Pileus not with these colours

68. Spores elongated to cylindrical

69. Spores (10-)13.5-15(-17) x (5.5-)6-7.5 µm. Associated with Alnus viridis: M. alnetorum

69. Spores 9-12.5(-13.8) x 4.5-6(-6.5) µm. Growing on various trees, mainly decidious trees: M. abramsii

68. Spores pip-shaped

70. Spores broadly pip-shaped.

71. Pileus very dark grey to almost blackish. Stipe at first blackish grey, then more brownish, fragile. Cheilocystidia 35-70 x 11-22.5 µm, clavate, smooth or covered with finger-like excrescences: M. tristis

71. Pileus brownish to grey-brown. Stipe grey to brownish grey, cartilaginous-brittle. Cheilocystida 21.5-55 x 5.5-11 µm, variously shaped, smoth or with a few coarse excrescences: M. polygramma

70. Spores pip-shaped or somewhat elongated. Pileus sepia brown. Odour nitrous. Cespitose on coniferous wood: M. stipata