Mycena alphitophora (Berk.) Sacc.

= Mycena floccifera Mez
= Mycena osmundicola J. E. Lange

Solitary or gregarious on fern rhizomes in hot-houses. In nature this species, originally described from The Bermudas, grows on various kinds of vegetable debris, but in Europe it is almost exclusively associated to hot-houses. It has been reported from North America, South America, Europe, Africa, Sri Lanka, Japa, Caribbean, and Hawaiian Islands (Desjardin 1995). It may occasionally occur in nature in Europe too (Moser 1977).

Pileus up to 10 mm across, at first narrowly ellipsoid with incurved margin, then campanulate, finally with flaring margin, deeply sulcate, translucent-striate, densely white-furfuraceous or powdery-floccose, somewhat glabrescent toward the margin with age, greyish beneath the furfuraceous covering, gradually turning white except at the centre. Flesh very thin. Odour not noted. Lamellae circa 18 reaching the stipe, tender, ascending, free to narrowly adnate, narrow to slightly ventricose, about 0.5 mm broad, thin, smooth, apparently white when fresh, with finely fimbriate, concolorous edge. Stipe up to 35 mm long, 0.2-0.6 mm wide, at times somewhat broadened at the base, without disc, densely white-puberulous to almost wooly-hisute, white.

Basidia 4-spored, clamped. Spores 8.1-9.7 x 4.5-5.5 µm, pip-shaped, weakly amyloid. Cheilocystidia 23-31 x 8-14.5 µm, clavate to fusiform,rather sparsely covered with cylindrical excrescences up to 3 µm long. Hyphae of the pileipellis verrucose, the terminal cells globose to pyriform verrucose to spinulose. Caulocystidia up to 300 x 6.5 µm, cylindrical, septate at the base, verrucose to spinulose.

The macroscopic description above is based entirely from Maas Geesteranus (1983). The microscopic details have also been taken from the same source but somewhat shortened.

In Europe M. alphitophora can be found on fern rhizomes in orchid greenhouses. It is a typical member of sect. Sacchariferae because of the small size, the granular or floccose pileus, the amyloid spores, and the large, spinulose caulocystidia. It is characterized by the following features (Desjardin 1995: 51):

  1. a small (1-10 mm diam), sulcate, greyish pileus with white granules that becomes white overall in age
  2. close, ascendent, subfree, narrow, white lamellae
  3. a white, puberulous to hisute stipe up to 50 x 0.5 mm that is sometimes broadened or subbulbous at the base but lacks a basal disc
  4. ellipsoid basidiospores in the range 7.5-10 x 4.5-5.5 µm
  5. 4-spored, clamped basidia
  6. sparsely spinulose, clamped cheilocystidia
  7. no cherocytes
  8. densely spinulose caulocystidia up to 300 x 3.5-13 µm with the apical spinulae often longer than the other spinulae
  9. broadly clavate cystidia at the junction of the stipe with the substrate

Mycena adscendens (Lasch) Maas Geest. differs in having a small basal disc, cheilocystidia wiith a slender neck, and smooth caulocystidia. Mycena corynephora Maas Geest. has subglobose to globose spores and mainly clavate caulocystidia.

In Norway M. alphitophora has been reported by Bendiksen & Metsänheimo (1987).

Further images on the web:

D. E. Desjardin


© Arne Aronsen 2002-2015