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

Summary:
Features include 1) a buff to yellow brown or rusty brown cap, 2) brownish flesh that typically turns blue when cut, 3) irregular somewhat radial pores that are yellow to brown and stain blue to bluish black when bruised, 4) a stem that is cap-colored except at the base where it is bright yellow, and 5) peppery taste.

Chalciporus piperatoides is found from NY to CA (Bessette), in the Pacific Northwest at least in WA and OR, (collections at the University of Washington, observed in OR by L. Norvell, pers. comm.). It appears on foray lists from BC where it is much less common than Chalciporus piperatus.

Cap:
3-8cm, obtuse to convex, becoming broadly convex to nearly flat, sometimes with broad umbo, margin may be uplifted when old; "buff to yellow-brown, orangish-brown or rusty brown"; smooth or nearly smooth, dry, viscid when moist; margin with narrow band of sterile tissue, (Bessette), 3-6cm, obtuse becoming flat or the margin becoming uplifted; tan to dull orange-cinnamon, margin close to cinnamon-buff; soft (like kid leather), subviscid, (Smith)

Flesh:
"pale pinkish buff to dull pinkish brown or dull yellow-brown", typically turning blue when cut, at least above the tubes, (Bessette), thick, pale pinkish buff, when cut slowly dull blue; in stem base lemon-yellow, (Smith)

Pores:
up to 1.5mm wide, irregular, somewhat boletinoid [radially arranged and elongated], "dull yellow at first, becoming yellow-brown to orangish brown, dull cinnamon or brown, often with an olive tinge, staining blue to bluish black when bruised"; tube layer 0.5-1cm thick, (Bessette), 2-3 per mm; yellow-brown, staining bluish; tube layer up to 1cm thick, decurrent, dull ochraceous, staining dingy inky blue when bruised, (Smith)

Stem:
3-8cm x 0.5-1.6cm, nearly equal, solid; colored as cap or paler, with bright yellow basal mycelium; "dry, fibrillose-punctate to fibrous-striate"; partial veil and annulus absent, (Bessette), 4-6cm x 0.4-0.6cm, solid; dingy yellowish brown, base coated with lemon-yellow mycelium; bald apart from mycelium at base, (Smith)

Chemical Reactions:
cap cuticle dark rusty brown to blackish with application of KOH, flesh dull brown to purplish red or gray with application of KOH, (Bessette), flesh bluish gray with FeSO4, with flesh in KOH a yellow pigment dissolves into the mount, the reaction of the cap surface soon brownish, (Smith)

Taste:
slowly acrid [peppery] (Bessette), slowly peppery (not as hot as B. piperatus), (Smith)

Microscopic:
spores 6-10 x 3-4 microns, subfusiform [somewhat spindle-shaped], smooth, yellowish to pale brown, (Bessette), spores 7-9(10) x 3-3.5 microns, somewhat boat-shaped, smooth, in Melzer''s fleeting amyloid fresh and as revived pale bister to dingy pale tan, in KOH pale clay color soon fading to bright yellow singly and more brownish in groups; basidia 4-spored, 23-28 x 5.5-7.5 microns, clavate, colorless to yellowish in KOH; pleurocystidia 36-57 x 7-12 microns, narrowly fusoid-ventricose to subcylindric, colorless to yellow in KOH and Melzer''s reagent, cheilocystidia similar but smaller and content yellow to yellow-brown; cap cuticle of "interwoven hyphae 4-8 microns wide, yellowish in KOH and with end-cells tubular to narrowly clavate, the walls showing a slight tendency to become roughened"; stem cuticle with fertile patches near top of stem with basidia and cystidia resembling those in hymenium; tube trama sections mounted in Melzer''s and crushed become dark greenish to bluish green under microscope (but no localized amyloid reaction is present); clamp connections absent, (Smith)

Spore Deposit:
dark smoky olive when fresh, rusty cinnamon when dry, (Bessette)