Cap: 4-13 cm across; convex, becoming broadly convex; dry; finely velvety when young, with a resinous feel; sometimes becoming more or less bald by maturity; brownish red to orangish red, with a thin layer of brownish to olive brown fuzz that can be rubbed away; sometimes with mottled yellow and red shades; when fresh bruising deep violet, then slowly blackish; margin at first inrolled and yellowish, with a narrow sterile overhang.
Pore Surface: Initially dark orangish red; fading to orange; bruising promptly dark blue or nearly black; 3-4 round pores per mm; tubes to 1 cm deep.
Stem: 4-10 cm long; 1-1.5 cm thick; more or less equal; often curved near the base; not reticulate; yellow, coated with red, especially toward the base; bruising blue; basal mycelium whitish to yellow, bruising dark red.
Flesh: Yellow in the cap; darker yellow in the stem; promptly bluing when sliced.
Odor and Taste: Not distinctive. Some people can detect a distinctive almond odor.
Chemical Reactions: Ammonia negative on cap surface; orangish on flesh. KOH orange to red on cap surface; orange on flesh. Iron salts negative on cap surface; negative on flesh.
Spore Print: Olive.
Microscopic Features: Spores 9-15 × 3.5-4.5 µ; smooth; fusiform; yellow in KOH. Hymenial cystidia inconspicuous; yellow in KOH; widely fusiform; to about 50 µ long. Pileipellis a tightly packed trichoderm of hyphae 2.5-5 µ wide; yellowish to yellow in KOH; terminal elements cylindric with rounded apices, or aciculate, with subacute apices. Some pileipellis and subcuticular elements pinkish red in Melzer’s reagent. Caulocystidia of two types: fusoid-ventricose, yellow in KOH, 25-25 µ long; or fusiform to fusoid-ventricose with an extended mucro, to 100+ µ long.
Catalog #: 10055
Taxon: Boletus subluridellus A.H. Sm. & Thiers
Determiner: A. H. Smith
Type Status: Holotype
Collector: A. H. Smith 64046
Locality: USA, Michigan, Washtenaw, Ypsilanti Golf Course, Ypsilanti
Habitat: In grassy oak woods
Occurrence Remarks: Boletes Mich. 1971 pg. 349.