Mycologia 102(2): 442. 2010.
Common Name: none
Pileus 60-100 (130) mm broad, convex, broadly so in age, disc occasionally depressed; margin inrolled in youth, decurved in age, sometimes uneven and wavy; surface viscid, frequently with adhering debris, more or less glabrous, unevenly dingy brown to liver brown when young, becoming dingy reddish brown to pinkish brown, shading to a paler margin, occasionally developing greenish blotches or spots in age; context soft, up to 30 mm thick, white to pale yellow, unchanging; odor not distinctive; taste mild.
Pores irregularly shaped, at maturity approximately 1/mm, subboletinoid, dull yellow; tubes up to 10 mm long, concolorous with pores, unchanging; adnate to slightly decurrent in attachment.
Stipe 20-50 x 20-30 mm in width, relatively short and stout, equal to slightly enlarged at the base, solid; surface sparsely covered with appressed fibrils, yellowish at apex, discoloring rusty-brown below, glandular pits when present, inconspicuous; context firm, white to pinkish cream becoming tawny to rust brown near base; partial veil absent.
Spores 7-10 x 2-3 microns, oblong to subfusoid in face view, slightly inequilateral in profile, smooth, thin-walled with granular contents; spores hazel brown in deposit.
Scattered or in small groups under Bishop pine (Pinus muricata), Monterey pine (Pinus radiata), and probably other pines along the California coast and Sierra Nevada; fruiting from late fall to winter; occasional to locally common.
Probably edible, but the viscid, debris incrusted, soon putrescent, often larva infested fruiting bodies should deter all but the desperate.
Suillus quiescens is a relatively recently described species of slippery jack. In the San Francsico Bay area it occurs mostly under Monterey pine where it has been mistaken for Suillus brevipes which is not surprising as the two have similar viscid brownish caps and tend to lack glandular stipe dots. Suillus quiescens, however, is typically larger and more robust with a subtly different colored cap and stipe. When young, the cap is paler than S. brevipes, becoming unevenly liver brown, dark reddish brown to pinkish brown, frequently with a pallid margin. In comparison, the cap of Suillus brevipes is more uniformly dark reddish brown fading to cinnamon brown. Additional distinguishing characters are a yellowish stipe apex in Suillus quiescens versus white in Suillus brevipes; finally, only Suillus quiescens occasionally exhibits greenish splotches or spots on older caps. Interestingly, Suillus quiescens was first described from Santa Cruz Island in southern California under Bishop pine. It is now known to occur with Bishop and Monterey pines along the California coast and probably occurs with other pines as well, including those in the Sierra. In the San Francisco Bay area, Suillus quiescens is less common than Suillus pungens and Suillus fuscotomentosus, two other pine dwelling slippery jacks. The latter species are easily distinguished by stipes with well-developed glandular dots. See those descriptions for more information.
Bruns, T.D., Grubisha, L.C., Trappe, J.M., Kerekes, J.F. & Vellinga, E.C. (2010). Suillus quiescens, a new species commonly found in the spore bank in California and Oregon. Mycologia 102(2): 438-446. (Protologue) (PDF)