Distinguishing Characters: Boletoid stature; pileus dull orange brown to reddish brown, fibrillose, viscid, margin somewhat covered with evanescent, thin, floccose veil remnants; pore surface yellowish, bruising brownish orange, depressed to decurrent; stipe glandulose, reddish brown with pallid yellow background, greenish or bluish stains normally developing at base; veil evanescent, thin, floccose whitish to yellowish; spores subellipsoid to subcylindric, smooth, (7) 8.0-10.0 (11) x 3.0-3.7 (4) µm; growing in association with Douglas fir - Pseudotsuga menziesii (Mirbel) Franco.

Compare: Suillus cavipes - stipe concolorous with pileus and yellow at apex, hollow at base; veil remnants often more prominent on stipe and at pileus margin; spores 7.0-10.0 x 3.5-4.0 µm. Suillus fuscotomentosus - basidiocarps normally robust; pileus brownish to dark brown; pore surface typically not staining or staining slowly; stipe conspicuously glandulose, becoming darker when handled; spores 9.0-12.0 x 3.0-4.0 µm. Suillus tomentosus - basidiocarps normally robust; pileus pallid yellow, orangish yellow to pallid yellowish brown, bruising bluish; stipe conspicuously gladulose, bruising bluish; spores 7.0-10.0 (12) x 3.0-4.0 (5) µm.

Bassette, A.E., W.C. Roody and A.R. Bessette. 2000. North American Boletes: A Color Guide to the Fleshy Pored Mushrooms. Syracuse University Press, Syracuse.

Thiers, H.D. 1975. California Mushrooms: A Field Guide to the Boletes. Hafner Press, New York.

Thiers, H.D. 1976. Boletes of the Southwestern United States. Mycotaxon 3: 261-273.

Smith, A.H. and H.D. Thiers. 1964. A Contribution Toward a Monograph of North American Species of Suillus. Privately published, Ann Arbor.