Mycena septentrionalis Maas Geest.

Proc. K. Ned. Akad. Wet. (C) 87(4): 442 (1984).

© A. Aronsen
Loftseik, Tønsberg, Vestfold: 19 November 2003

Gregarious in coniferous woods, mainly under Picea. Autumn. Occasional, but locally common in the Nordic countries. Also recorded in Germany and Scotland. Widely distributed in Norway, but not very common. Most records in the south-east part of the country.

Pileus 5-22 mm across, conical, campanulate to convex, sometimes with an umbo, sulcate, translucent-striate, at first white-pruinose and then often looking almost bluish black, glabrescent, dark sepia brown at the centre, paler to whitish towards the margin. Lamellae 17-20 reaching the stipe, ascending, narrowly adnate with a decurrent tooth, pale grey or grey with a brownish shade, the edge paler. Stipe 25-80 x 0.5-2 mm, hollow, terete, straight to somewhat curved, equal, pruinose above, glabrous below, whitish to greyish above, pale brown below. Odour of Pelargonium graveolens, sometimes indistinctive.

Basidia 25-40 x 6-8, slender-clavate, 4-spored, with sterigmata 3-5 μm long. Spores (7.5-)8-9(-10.5) x (3.5-)4-5.1 μm, Q 1.6-2.1, Qav≈1.9, pip shaped, amyloid. Cheilocystidia 12-46 x 7-18 μm, forming a sterile band, saccate or more or less shaped like an hour-glass, with broad base, some more clavate, obpyriform or spheropedunculate, covered with few to more numerous warts or cylindrical, branched and curved, fairly coarse excrescences, 1-10 x 1-2 μm. Pleurocystidia similar. Hyphae of the pileipellis 1.5-3.5 μm wide, covered with straight to curved or much branched excrescences 1-20 x 1-2 μm, forming dense, corralloid masses. Hyphae of the cortical layer of the stipe 1.5-3.5 μm wide, smooth to diverticulate, excrescences 0.5-4 x 1-1.5 μm, the terminal cells up to 10 μm wide, variously inflated, covered with fairly coarse excrescences. Clamp connections present at all tissues.

Microphotos of cheilocystidia.

Mycena septentrionalis was a well known species in Scandinavia, known as Mycena sepia sensu Lundell. Maas geesteranus (1984), however, showed that the original M. sepia was another species and proposed the new name M. septentrionalis. He stressed the resemblance between M. septentrionalis and M. filopes and focused on several features to separate the two species: In M. septentrionalis the cheilocystidia are mostly covered with unevenly spaced, coarse, often curved, simple to branched excrescences, and many cystidia are saccate or shaped like an hour-glass, with the apical part and the base equally broad. In M. filopes the cheilocystidia are mostly covered with evenly spaced, cylindrical, narrow excrescences, not shaped like an hour-glass. The terminal cells of the stipe cortex can also be used to separate the two species. In M. septentrionalis they are covered with fairly coarse excrescences, while they are covered with fine and slender ones in M. filopes. In addition he mentioned the odour, which is of iodoform when drying out in M. filopes and pungent-aromatic, of Pelargonium graveolens in M. septentrionalis.

In my opinion Maas Geesteranus exaggerated the problem. There are small chances to mix up the two species. Probably, M. metata is more likely to be confused with M. septentrionalis. They often grow together, but that shoudn't be a problem either. M. septentrionalis should be readily recognized in the field on account of the dark, sepia brown pileus, the grey to brownish lamellae with a decurrent tooth, and the smell of Pelargonium. The odour may be absent, but according to my experience it is quite constant. Microscopically the hour-glass shaped cheilocystidia is a reliable character.

An equally dark brown species is M. rapiolens, but this has large, clavate cheilocystidia that are not constricted, much wider hyphae of the pileipellis and very rare or absent clamps.


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