> Easily recognized species. (1/2)

° Cap dry and smooth, whitish, with an even margin by maturity; pore surface white becoming yellowish to olive; stem whitish to pinkish or brownish; flesh white, not staining on exposure; cap orangish with ammonia; spores 13-15 µ long; found under Ponderosa Pine and other conifers (also Coast Live Oak); in and west of the Rockies. (1/4)

Boletus barrowsii

° Cap dry, smooth or finely hairy, grayish, with an even margin; pore surface white becoming grayish to brownish; stem whitish, developing bright yellow stains; flesh whitish, not staining on exposure or becoming dingy; cap negative with ammonia; spores 9-13 µ long; found under hardwoods; widely distributed. (2/4)

Retiboletus griseus

° Cap dry, velvety to hairy, dark red to reddish brown, with an overhanging sterile margin; pore surface yellow to greenish yellow; stem reddish, coarsely reticulate and shaggy; flesh pale yellow, not staining on exposure; cap reaction to ammonia not recorded; spores 16-24 µ long; found under conifers (sometimes growing from decayed wood); widely distributed. (3/4)

Aureoboletus mirabilis

° Cap dry, smooth or finely velvety, pale pinkish, with an overhanging sterile margin; pore surface yellowish becoming olive, bruising bluish weakly or not at all; stem yellow above, whitish below, with white reticulation; flesh pale yellow, sometimes staining bluish on exposure; cap reaction to ammonia not recorded; spores 11-13 µ long; found under oak; Arizona. (4/4)

Boletus pulchriceps

> Not as above. (2/2)

° Pore surface initially white or whitish. (1/2)

The mushrooms below form the western Boletus edulis cluster.

~ Cap dry or moist, smooth or pitted, dark brown, with an even margin; pore surface white becoming yellowish; stem white developing pinkish brown shades; flesh whitish or pale pinkish, not staining on exposure; cap reaction to ammonia not recorded; spores 12-14 µ long; found under hardwoods; California. (1/4)

Boletus aereus
At MykoWeb

~ Cap sticky when fresh, smooth or wrinkled, brown to reddish brown, with an even margin; pore surface white becoming yellowish, then olive; stem white or pale brown, with white reticulation; flesh white, not staining on exposure; cap orange with ammonia; spores 13-19 µ long; found under conifers; widely distributed. (2/4)

Boletus edulis

~ Cap moist, conspicuously wrinkled, cinnamon brown, with an even margin; pore surface white becoming yellowish to olive; stem whitish or cinnamon; flesh white, not staining on exposure; cap negative with ammonia; spores 14-17 µ long; found under conifers; California. (3/4)

Boletus mottiae
At MykoWeb

~ Cap dry, usually somewhat wrinkled, reddish brown, with an overhanging sterile margin; pore surface white becoming yellowish, then olive, bruising rusty brown; stem white or yellowish above, brownish below, darkening on handling; flesh white, not staining on exposure; cap reaction to ammonia not recorded; spores 15-20 µ long; found under conifers; widely distributed. (4/4)

Boletus pinophilus

° Pore surface initially pale to bright yellow. (2/2)

~ Cap with an overhanging sterile margin, at least when young. (1/2)

* Cap dry and smooth, reddish to yellowish brown; pore surface pale yellow becoming dark yellow or olive; stem yellow with reddish brown stains; flesh yellow, sometimes staining blue exposure; cap reaction to ammonia not recorded; spores 12-16 µ long; found under oaks; California and Oregon. (1/3)

Boletus appendiculatus
At MykoWeb

* Cap dry and velvety, brown; pore surface bright yellow; stem white to pale yellow, with an orange-yellow apex; flesh whitish, not staining on exposure; cap dark purplish red with ammonia; spores 10-14 µ long; found under oak; California. (2/3)

Boletus citriniporus
At MykoWeb

* Cap dry, velvety, brown; pore surface yellowish, usually bruising greenish, then brownish; stem yellow with reddish brown stains; flesh whitish, sometimes staining bluish on exposure; cap reddish brown with ammonia; spores 10-15 µ long; found under hardwoods or conifers; widely distributed. (3/3)

Xerocomus subtomentosus

~ Cap margin even. (2/2)

* Cap dry, smooth to nearly velvety or hairy, brown; pore surface pale yellow becoming dark yellow, not bruising; stem pale yellow at apex, brown below; flesh white, not staining on exposure; cap red or pink with ammonia; spores 13-18 µ long; found under conifers; Pacific coast. (1/3)

Boletus fibrillosus
At MykoWeb

* Cap slimy, fairly smooth, cinnamon to reddish brown; pore surface bright yellow becoming greenish; stem yellow above, reddish brown to whitish below; flesh whitish or pale pinkish, not staining on exposure; cap slowly orange with ammonia; spores 11-15 µ long; found under hardwoods; California and Oregon. (2/3)

Boletus flaviporus
At MykoWeb

* Cap dry, velvety, olive to reddish brown or brown; pore surface yellowish to olive, usually bruising bluish; stem yellowish with brownish stains; flesh pale yellow, sometimes staining bluish on exposure; cap with a green flash, then reddish brown with ammonia; spores 10-14 µ long; found under hardwoods or conifers; widely distributed. (3/3)

Xerocomus ferrugineus