Summary:
Features of this common bolete include 1) plush maroon brown cap, 2) stem of similar color, often with roughened longitudinal ridges reminiscent of bark, sometimes netted near the top, 3) yellow pores that do not stain blue, and 4) growth on or near rotting conifers. A whitish then yellow stage of the pyrenomycete Hypomyces chrysospermum frequently grows on it. The Aureoboletus name was proposed in Halling(6) in 2015 and supported in 2020 by the molecular study of Kuo(12).

Odor:
acid or mild (Thiers), pleasant (Phillips)

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

Microscopic:
spores 18-24 x 7-9 microns, spindle-shaped to elliptic, smooth, (Arora), spores 18-22 x 7-9 microns, subfusoid to subelliptic, smooth, dark brown in Melzer''s, ochraceous in KOH, thick-walled; basidia 4-spored, 31-36 x 7-11 microns, clavate, colorless; hymenial cystidia scattered to numerous, 60-90 x 10-18 microns, fusoid-ventricose with obtuse to elongated apices, colorless, thin-walled; clamp connections absent, (Thiers)

Spore Deposit:
olive brown (Arora, Thiers)

Notes:
'Boletus'' mirabilis is common in WA and OR and also found in northern CA, (Thiers), ID (Drew Parker, pers. comm.), MT (Larry Evans, pers. comm.), and MI (Arora). It is also common in BC and there are collections at the University of British Columbia.

EDIBILITY

choice (Thiers), delicious, some have a distinct lemony flavor, avoid specimens attacked by Hypomyces, (Arora)

Synonyms and Alternate Names:
Lycoperdon pyriforme Schaeff.
Morganella pyriformis (Schaeff.) Kreisel & D. Krueger