Distinguishing Characters: Boletoid stature; pileus yellowish, pallid yellowish brown to pallid brown, glabrous, glutinous; pore surface yellowish, depressed to subdecurrent; stipe conspicuously glandulose, whitish background with yellowish apex, vinaceous stains developing toward base; veil lacking; spores ellipsoid to subcylindric, smooth, 7.6-9.5 x 3.2-4.5 µm; growing in association with conifers, especially Ponderosa pine - Pinus ponderosa P. & C. Lawson.
Compare: Suillus granulatus - pileus brown, reddish brown to dark brown; spores 7.0-9.0 x 2.5-3.5 µm. Suillus occidentalis - stipe not conspicuously gladulose; spores 8.0-9.6 x 3.0-4.0 µm. Suillus wasatchicus - pore surface covered in conspicuous reddish glandulae, particularly noticeable when immature; stipe lacking vinaceous stains toward base; spores 8.0-10.4 x 1.5-2.0 µm.
Citations
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.
