Summary:
Features include a pale buff to tan cap, yellow flesh and pores that turn blue on exposure, a smooth stem that when young is yellow at the top and red at the base but when old is typically dark red throughout, and a usually bitter taste.

Chemical Reactions:
flesh stains yellow-orange with application of KOH (Bessette)

Odor:
unpleasant or not distinctive (Bessette), often strong, unpleasant (Thiers)

Taste:
usually bitter (Arora), bitter (Bessette)

Microscopic:
spores 12.5-17.5 x 4-5 microns, spindle-shaped to elliptic, smooth, (Arora), spores 12-18 x 4-5 microns, subfusoid to subcylindric, smooth, ochraceous, (Bessette), spores 12.5-17.6 x 4-5 microns, subcylindric to subfusoid to narrowly subelliptic, smooth, ochraceous in KOH, dark ochraceous in Melzer''s, thin-walled; basidia 4-spored, 26-30 x 7-13 microns; hymenial cystidia scattered, 24-35 x 5-7 microns, embedded in hymenium, fusoid to occasionally clavate or fusoid-ventricose, colorless, thin-walled; cap cuticle a trichodermium of interwoven hyphae, occasionally incrusted; clamp connections absent, (Thiers)

Spore Deposit:
olive-brown (Arora, Bessette)

Notes:
Caloboletus rubripes is found in the Pacific Northwest, Southwest, and Mexico, and is especially common in NM and CO, (Bessette). It is specifically found in WA and OR (collections at the University of Washington), and is recorded also from ID and CA, (Michelle Seidl, pers. comm.). It has been reported from MT (Larry Evans, pers. comm.), A Paul Kroeger collection from BC is deposited at University of British Columbia.

EDIBILITY

inedible because bitter (Bessette)

Synonyms and Alternate Names:
Hydnum imbricatum L. ex Fr.