Pileus 7-14 cm broad, glabrous, obtuse expanding to broadly convex, glutinous overall, but soon dry, more or less rugulose, variegated cinnamon, reddish brown, and pale alutaceous (rarely uniformly colored). Context firm but soon soft, whitish to yellowish, staining blue then fuscous, in age lemon yellow throughout and then not bluing so readily. Taste mild; odor agreeable, fruity.
Tubes up to 8 mm deep (rather shallow), primuline to golden yellow, becoming dingy olive ochre to dusky olive brown, arcuate to short decurrent; pores concolorous with sides of tubes, almost round to obscurely boletinoid, sublamellate near pileus margin for a short distance, becoming compound and finally about 1 mm wide.
Stipe 8-11 cm long, 22-33 mm thick, equal or attenuated near base (not rooting), solid; surface pallid to dingy pale yellowish to brownish, apical part ferruginous-squamulose to furfuraceous, slightly ornamented in the same way below the annulus, ornamentation less pronounced downward; veil with the outer layer glutinous (copiously so), inner layer whitish to yellowish and membranous; annulus becoming appressed to stipe and lacerate to denticulate on both margins, at times oblique, superior.
Spore print color unknown. Spores 7.5-9.8 X 3.2-3.8 Ám, apparently oblong in face view and subfusoid in profile, pale melleous, smooth, walls thin.
Basidia 29-30 X 6-7 Ám, elongate, clavate, four-spored. Hymenial cystidia 48-84 X 4-10.5 Ám, solitary or in fascicles, incrusted, pigment vinaceous in KOH, cylindric to somewhat ventricose. Subhymenium of irregular small elements, with incrusting pigment vinaceous in KOH.
Tube trama bilateral, gelatinous, mediostratum of yellowish somewhat interwoven hyphae. Pileus cuticle a thick gelatinous layer of hyphae 1-2.2 Ám wide, some yellowish incrustations present. Clamp connections absent.
Chemical reactions unknown.
Habit, habitat, and distribution On the ground in mixed woods of Sequoia and Lithocarpus during the winter rainy season.
Observations This is a species of Suillus that has not been collected by the author; this description is taken from the original by Singer. It was described by him from collections made in Muir Woods National Monument in Marin County in 1958, where it is apparently very rare since year around collecting in that area since 1959 has failed to reveal it. There is some confusion regarding its relationship with other Suilli and boletes. Singer recently transferred it to the genus Pulveroboletus. However, it is the opinion of this author that it should remain in Suillus because of the presence of clustered cystidia, small pores, viscid pileus, and the presence of an annulus. Since no collections have been seen, no comments can be made regarding its affinities with other species.
The Boletes of California
Copyright © 1975 by Dr. Harry D. Thiers
Additional content for the online edition © 1998 by Michael Wood, Fred Stevens, & Michael Boom
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