Boletus fibrillosus Thiers
no common name
Boletaceae

Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.

Introduction to the Macrofungi

Photograph

© Michael Beug     (Photo ID #14852)


Map

E-Flora BC Static Map

Distribution of Boletus fibrillosus
Click here to view the full interactive map and legend

Species Information

Summary:
Features include dark brown to chestnut brown, dry, fibrillose cap, yellow pores, and brown reticulate stem.
Chemical Reactions:
cap cuticle red to pink with application of KOH
Microscopic:
spores 13-17.5 x 3.5-5.5 microns, subfusoid [somewhat spindle-shaped] to ventricose [wider in middle], smooth, pale ochraceous in Melzer''s, pale yellow to colorless in KOH, moderately thick-walled; basidia 4-spored, 35-40 x 8-12 microns, clavate, colorless in KOH; hymenial cystidia scattered, inconspicuous, 38-46 x 6-8 microns, subcylindric to fusoid-ventricose with elongated apices, colorless, thin-walled; cap cuticle differentiated as a trichodermium of hyphae have +/- equal cells; stem cuticle differentiated as a layer of fertile basidia and caulocystidia, which are colorless, subcylindric to clavate, abundant on edges of reticulum
Spore Deposit:
dark olive-brown
Notes:
The description is derived from Thiers except where indicated. Boletus fibrillosus is "recorded from the Pacific Coast of California and the Cascades, distribution limits yet to be established" (Bessette). The type is from CA. There are collections from WA and OR at the University of Washington. Paul Kroeger says Boletus fibrillosus appeared in quantity in BC about 2004, and a collection from 2005 in BC is at the University of British Columbia.
EDIBILITY
unknown (Thiers), edible but inferior to B. edulis (Trudell)

Habitat and Range

SIMILAR SPECIES
Boletus edulis has a smooth to wrinkled or pitted (not fibrillose) cap that is lighter in color and slippery to viscid when wet, white tubes when young, and a stem that is lighter in color, (Thiers). See also SIMILAR section of ''Boletus'' mirabilis and Boletus mottiae.
Habitat
single to scattered in soil in dense mixed coastal forests, (Thiers), in dense mixed coastal forests or in conifer woods (Bessette), in old growth forests of Abies (fir) and Tsuga heterophylla (Western Hemlock), earlier succession forests of T. heterophylla and Pseudotsuga menziesii (Douglas-fir) and other mixed forest stands, (Trudell)

Synonyms

Synonyms and Alternate Names:
Cantharellus floccosus Schwein.
Gomphus floccosus (Schwein.) Singer