Mycena tenerrima (Berk.) Quél.

= Mycena nucicola Hujsman

© Leif Örstadius 329-05


Growing on fallen Corylus fruits. Very rare.

Pileus 1.5 - 5 mm across, at first conical, becoming parabolical with age, translucent-striate when old, shallowly sulcate, furfuraceous or floccose, becoming puberulous to glabrous, white. Lamellae 11 - 13, not always reaching the stipe, ascending, the edge convex, narrowly adnate, white. Stipe up to 30 mm long, filiform, straight to flexuous, equal, the base somewhat bulbous, entirely pubescent or hairy, glabrescent, watery greyish, with age more whitish, with a very small basal disc, which is almost disappearing with age.

Basidia c. 17 x 8 µm, clavate, 4-spored. Spores (7-) 8.2-8.8 (-10) x (3.8-) 4.5-4.5 (-5.5) µm, pip-shaped, amyloid. Cheilocystidia 15-26 x 8-16 µm, clavate, densely covered with evenly spaced, short excrescences, with or without a shorter or longer, often flexuous rostrum. Hyphae of the pileipellis up to 15 µm wide, densely covered with narrow, short excrescences; the terminal cells broadly clavate to globose, up to 30 µm wide, densely covered with short excrescences 0.5-1.5 x 0.5 µm (acanthocysts) . Hyphae of the cortical layer of the stipe smooth, covered with globose to broadly clavate acanthocysts, similar to the terminal cells of the pileipellis; the caulocystidia up to 100 µm long, smooth, thin-walled, lanceolate, acute, with a broadened base up to 13 µm wide. Hyphae of the basal disc terminated by cells of two types: 1) elements similar to the caulocystidia, up to 50 µm long, clavate or lanceolate, entirely smooth or 2) elements similar to those on the pileipellis, 15-40 µm, clavate to subglobose, densely covered with short excrescences (acanthocysts). Clamp connections rare on tramal hyphae.

More microscopic figures.

This taxon has been regarded as a separate species under the name Mycena nucicola Hujsman. Maas Geesteranus (1991b) and Desjardin discussed the differences between M. nucicola and M. tenerrima (see this). Recent ITS sequences of Norwegian and Swedish collections determined as M. tenerrima and M. nucicola indicates, however, that the two taxa belong to the same species (Aronsen & Larsson 2015). Therefore, I treat M. nucicola as a synonym.

NORWAY, TJØME, Hvasser, Sønstegård 19 Nov. 2006.
Two specimens on fallen fruit of
Corylus avellana, leg. A. Aronsen.




© Arne Aronsen 2002-2018