Mycena kuehneriana A. H. Smith - a rare species of Mycena

In his tentative subdivision of the genus Mycena in the northern hemisphere, R. A. Maas Geesteranus (1980) includes six species in the section Calodontes (Fr. ex Berk.) Quél. They are placed in three subsections.

Some authors recognize M. rosea at the level of species, and the recent years even some new species in the section have been suggested: M. diosma (Krieglsteiner & Schwöbel, 1982), and M. lammiensis (Harmaja, 1985).

In Europe M. pelianthina, M. pura, and M. pearsoniana are all well-known species, and M. subaquosa has been reported from West-Germany (Krieglsteiner, 1982). M. kuehneriana has not been found in Norway earlier, and is here probably reported for the first time from Europe.

Description based on one single collection:

Pileus 21 mm broad, rather flattened with a somewhat depressed center, striate, moist, pale brown with a distinctly paler margin.

Lamellae ca 28 reaching the stipe, tender, horizontal, broadly adnate, long decurrent; white with a pink shade.

Stipe ca. 40 x 3 mm, hollow, minutely puberulous above, somewhat paler than the pileus; the base covered with coarse, whitish fibrils.

Odeur and taste of radish.

Basidia slender-clavate, 4-spored, clamped, 22,5-27 x 6,5-7 um; with sterigmata 5,5 um long.

Spores pip-shaped, almost cylindrical, smooth, amyloid, 7,2-9,0 x 3,6-4,5 um.

Cheilocystidia cylindrical, utriform, subfusiform, clamped, smooth, 36-75 x 9-18 um, forming a sterile band.

Lamellar trama vinescent in Melzer's reagent.

Hyphae of the pileipellis 4,5-9 um wide, smooth.

Hyphae of the cortical layer of the stipe 2,7-4,5 um wide, clamped, smooth; terminal cells more or less pronouncedly curved outwards, forming the caulocystidia 50-70 x 10-14,5 um, fusiform, clavate.

Habitat solitary on the ground under Fagus (one single Picea abies near by).

Norway, Vestfold, Sem, Gullkrona, 4 Nov. 1984. Leg. A. Aronsen, M 49/84, det. A. Aronsen / R. A. Maas Geesteranus

Smith (1947: 190) indicated that his M. kuehneriana was identical with M. pseudopura sensu Kühner (1938) non Cooke. The latter is a well-known species in Europe - now called M. pearsoniana Dennis ex Sing. (see Pearson, 1955) - and clearly differentiated from the former by having inamyloid spores.

My material fits well with Smith's description, characterized by the colour of the gills and the way they are attached to the stipe, the radish-like smell and taste, and the amyloid spores.

Smith has measured the spores of his M. kuehneriana to 5-6 x 2,5-3 um, i. e. both shorter and narrower than my measurements, and this should give some doubts concerning the identity ogf my material. But the measurements are - in his English description - probably due to an error. In the Latin description he has the spores as 5-7,5 x 2,5-4,5 um. Dr. R. A. Maas Geesteranus, who has examined the holotype of M. kuehneriana, measured the spores to 7,9-9,0 x 3,8-4,5 um. This corresponds very well with his measurements on my material. The other features of my material also correspond with the holotype.

M. kuehneriana and M. pearsoniana are extremely close, the only certain difference being in the spores which are amyloid in the former and inamyloid in the latter. Perhaps another difference is that M. pearsoniana is not common in Europe and unknown in North America while M. kuehneriana is rare both in Europe and North America. The habitat may also prove to be different.

M. pura, of the same section, also with amyloid spores, is a very variable species, but the gills will never be attached as in M. kuehneriana (Smith, 1947).

M. pearsoniana has also been collected in in Vestfold; the spores were distinctly inamyloid (G. Gulden, pers. comm.). Such finds must always be microscoped. Perhaps some of them will turn out to be M. kuehneriana. This was also emphasized by Krieglsteiner & Schwöbel (1982) who mentioned finds of M. pearsoniana from central Europe,

Acknowledgements.

My sincere thanks go to Dr. R. A. Maas Geesteranus, Leiden for providing me with microscopic drawings and notes on microscopic features, and for the informaton about the holotype of M. kuehneriana. I will also thank Mr. Ø. Weholt, Fredrikstad for helping me with microscopic features.

Sammendrag.

Mycena kuehneriana er ikke tidligere funnet i Norge, og er her trolig også rapportert for første gang fra Europa. Den er svært lik M. pearsoniana, som her også blir rapportert for første gang fra Norge (G. Gulden). Den viktigste forskjellen mellom de to artene er at M. kuehneriana har amyloide sporer mens M. peartsoniana har inamyloide sporer.

References:

Harmaja, H., 1985: Studies on white-spored agarics. Karstenia 25: 41-46.
Krieglsteiner, G. J., 1982: Über neue, seltene, kritische Makromyzeten in der Bundesrepublik Deutschland. IV. Z.Mykol. 49: 73-106.
Krieglsteiner, G. J. & H. Schwöbel, 1982: Mycena diosma spec. nov. und der Mycena-pura-Formenkreis in Mitteleuropa. Z. Mykol. 48: 25-34.
Kühner, R., 1938: Le Genre Mycena Fries. Encycl. Mycol. 10.
Maas Geesteranus, R. A., 1980: A tentative subdivision of the genus Mycena in the northern Hemisphere. Studies in Mycenas -15. Persoonia 11: 93-120.
Pearson, A. A., 1955: Mycena. Naturalist 2: 41-63.
Smith, A. H., 1947: North American species of Mycena. Ann Arbor.

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