E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Features include 1) whitish to grayish buff smooth cap with suede-like texture, 2) thick unchanging whitish flesh, 3) pores that are whitish when young and do not become blue when bruised, 4) whitish to buff stem that is reticulate at least on the upper part, and 5) mild taste. Trudell(4) comment, "Generally considered to occur only in the Southwest, there have been sporadic reports of it occurring in places such as Idaho and southern California, under trees other than ponderosa pine. In Seattle, a very similar mushroom is fairly common in late spring under oaks and species of Tilia [italicized], such as lindens and basswood. Although it was felt that this had to be a different species, preliminary DNA analysis suggests it is very close to B. barrowsii.".

If both close taxa are included, B. barrowsii found at least in ID, CA, AZ, NM, CO, and Mexico, (Bessette). The University of Washington has collections from WA and NM. It was reported from BC (Redhead(5)), and there are collections from BC at the University of British Columbia and the Pacific Forestry Center.

Cap:
6-30cm, obtuse to convex becoming broadly convex; margin incurved at first; white, whitish, or grayish buff; dry, smooth, (Bessette), (6)9-20(30)cm, white to whitish or buff during all stages, unchanging or becoming brown when bruised; dry, dull, smooth, sometimes obscurely rimose [cracked], when young often covered with easily removable pruinose coating, or appearing bald, (Thiers), 6-25cm, convex becoming broadly convex to flat; dull white to grayish or buff; dry, smooth or very slightly velvety, (Arora), whitish, creamy with a pinkish tinge, to buff; smooth or suede-like, (Phillips), whitish to pale tan; suede-like surface texture, (Trudell)

Flesh:
white, unchanging when cut, (Bessette), 2-3cm thick, white except sometimes pale vinaceous near cap surface, unchanging, (Thiers), thick; "white, not blueing when exposed (or blueing only very slightly near the tubes)", (Arora)

Pores:
1-2 per mm, angular, "white when young, becoming yellowish and finally olive or brownish at maturity, not blueing when bruised"; tube layer 1-2cm thick, (Bessette), 1-2mm, angular, white becoming yellowish when old, unchanging or darkening slightly when bruised; tube layer 1-2cm thick, colored as pores, (Thiers), white or pallid when young, becoming yellow to olive-yellow when old, not turning blue when bruised, (Arora)

Stem:
8-15.5cm x 2-5cm, nearly equal or widening downward, sometimes bulbous at base, stem solid; whitish to pinkish buff or tinged brownish; dry, finely reticulate [netted], at least on upper part, (Bessette), 8-15cm x 2-5cm, bulb up to 9cm wide, clavate or bulbous, sometimes base pointed; solid, whitish to pinkish buff or pinkish cinnamon, white at base, unchanging when bruised, reticulations typically fine and delicate, (Thiers), 6-20 x 2-6cm, equal or widening downwards, solid, firm; whitish to buff or cap-colored, sometimes with brownish stains; finely reticulate over at least upper part, (Arora)

Chemical Reactions:
flesh stains gray with application of FeSO4

Odor:
not distinctive (Bessette), pleasant (Phillips), mild or sometimes strong and unpleasant when dried, (Thiers), strong odor when drying (Trudell)

Taste:
not distinctive (Bessette), pleasant (Phillips)

Microscopic:
spores 13-15 x 4-5 microns, subfusoid [somewhat spindle-shaped] to subelliptic [somewhat elliptic], smooth, ochraceous, (Bessette), spores 13-15 x 4-5 microns, subfusoid to subelliptic, smooth, pale ochraceous in Melzer''s reagent and in KOH, thin-walled; basidia 4-spored, 25-34 x 8-11 microns, clavate; hymenial cystidia crowded on pores, scattered to numerous on sides of tubes, 37-50 x 5-9 microns, "cylindric to subclavate to obscurely fusoid-ventricose"; cap cuticle poorly differentiated as a cutis of appressed to slightly interwoven hyphae; no clamp connections, (Thiers)

Spore Deposit:
olive brown (Bessette), dark olive brown (Thiers)