Inocybe hirsuta var. maxima — Large scaly fibre/fibercap

Card image cap

Large scaly fibrecap2, photograph by Ludovic Le Renard.

Card image cap

Large scaly fibrecap11, photograph by Ludovic Le Renard.

Poisonous?

Gills: Adnate to adnexed, initially grey, then reddish brown
Spore print: Brown


Odour: Fruity or fishy.
Cap: 2–8 cm in diameter, bell-shaped to convex. Beige to dark brown and shaggy, covered by darker brown or reddish, fibrous scales.
Flesh: Whitish or beige, may turn red on bruising.
Gills: Attached to the stem, sometimes only narrowly attached and pulling free as they dry. Pale grey when young, may turn red on bruising, with age becoming brown like the cap. Gill edges lighter than gill faces.
Stems: 4–10 cm long x 0.3–0.5 cm wide, scaly, light tan to brown, with shaggy reddish or brownish fibrils. Often with blue-green base.
Ring: Not evident.
Cup: None.
Spores: 8–12 x 4.5–7 µm, brown, smooth.
Cystidia: Elongate, thin-walled cells on the edge but not the sides of gills of this species; 30-45 x 10-13 µm, club shaped, without crystals.
Habitat: On soil, under conifers including western hemlock (Tsuga heterophylla), Douglas fir (Pseudotsuga menziesii), Sitka spruce (Picea sitchensis), ectomycorrhizal. Often solitary or in small groups.
Geographical distribution: Restricted to western North America based on collection localities1,5.

This species is recognizable as a fibrecap by its fibrous, conical caps and the brown spores. The blue to green base of the stem and the reddish bruising are distinguishing characters for a group of several species within Inocybe6 that are related to the European Inocybe calamistrata, the greenfoot fibrecap. However, BC and the Pacific northwest are rich in undescribed species within this group and the exact scientific name that should be applied to specimens illustrated here remains open to debate. The true I. calamistrata seems to be absent from the Pacific northwest and BC judging from differences between all of our DNA sequences and sequences from the European specimens that we presume are closer to the original concept of the species as originally described in Sweden in the early 1800’s.

Untested. The related greenfoot fibrecap apparently lacks muscarine, the main toxin in most Inocybe species7 and the outcome of tests for the presence of psilocybin were contradictory8,9.

Treatment10: Contact your regional Poison Control Centre if you or someone you know is ill after eating fibrecaps. Poison centres provide free, expert medical advice 24 hours a day, seven days a week. If possible, save the mushrooms or some of the leftover food containing the mushrooms to help confirm identification.

Poison Control:
British Columbia: 604-682-5050 or 1-800-567-8911.
United States (WA, OR, ID): 1-800-222-1222.

1
MyCoPortal. Mycology Collections Portal, <http://mycoportal.org/portal/collections/harvestparams.php> accessed March 2018.
2
Specimen Inocybe hirsuta var. maxima UBC F33244, GenBank #MG953983.
3
Siegel, N. & Schwarz, C. Mushrooms of the Redwood Coast. A Comprehensive Guide to the Fungi of Coastal Northern California. Ten Speed Press, Berkeley, California (2016).
4
Trudell, S. & Ammirati, J. F. Mushrooms of the Pacific Northwest. Timber Press, Portland, Oregon (2009).
5
Abarenkov, K. et al. PlutoF-a Web based workbench for ecological and taxonomic research, with an online implementation for fungal ITS sequences. Evol. Bioinf. 6, 189-196, doi:10.4137/ebo.s6271 (2010).
6
Jacobsson, S. Inocybe (Fr.) Fr. Pp. 868-906 in Funga Nordica, Agaricoid, Boletoid and Cyphelloid Genera (eds Knudsen, H. & Vesterholt, J.) Nordsvamp, Copenhagen (2008).
7
Kosentka, P. et al. Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fungi. Plos One 8, 9, doi:10.1371/journal.pone.0064646 (2013).
8
Stijve, T., Klan, J. & Kuyper, T. W. Occurrence of psilocybin and baeocystin in the genus Inocybe (Fr.) Fr. Persoonia 12, 469-473 (1985).
9
Gartz, J. Nachweis von Tryptaminderivaten in Pilzen der Gattungen Gerronema, Hygrocybe, Psathyrella und Inocybe. Biochemie und Physiologie der Pflanzen 181, 275-278 (1986).
10
Leikin, J. B. & Paloucek, F. P. Poisoning and Toxicology Handbook, 4th ed., CRC Press, Boca Raton, Florida (2008).
11
Specimen Inocybe hirsuta var. maxima UBC F32037, GenBank #KX236129.