The boletes of Michigan, by Alexander H. Smith and Harry D. Thiers.

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THE BOLETES OF MICHIGAN

obscuring cystidial detail.
Tube trama gelatinous, of divergent hyphae. Pileus cuticle of narrow
(2-4 i) gelatinous filaments forming a collapsing trichodermium, hyaline
in KOH and pale yellowish in Melzer's. Context of interwoven hyphae,
hyaline nonamyloid and with cells somewhat inflated. Caulocystidia in
numerous fascicles, the fascicles bister when revived in KOH. Clamp
connections absent.
Habit, habitat, and distribution.-Scattered to gregarious under
conifers, very abundant in conifer plantations in the southern part of
the state where it is regularly collected for the table under the name
"Slippery Jack."
Observations.-The well-formed annulus with the purplish drab to
vinaceous-brown zone or thin layer of fibrils over the outside, and which
usually gelatinizes, is the best field character for this species.
Material examined.-Livingston: Smith 66420. Oakland: Smith
64548. Washtenaw: Hintikka 10-6-61; Hoseney 10-22-65, 10-10-67; Kauffman 10-10-24, 10-1-24, 10-2-24, 8-16-25; Mains 32-825, 32-855; Rea 734;
Smith 18832, 51169, 56142, 58352, 62363, 66400, 72864, 9-?42.
14. Suillus lutescens Smith & Thiers
Contrib. toward a Monograph of N. Amer. Sp. of Suillus p. 71. 1964
Pileus 3-6 cm broad, convex to obtuse, expanding to nearly plane
or remaining broadly umbonate, glabrous, glutinous, "buffy brown" to
"pinkish buff' in age. Context yellowish pallid and slightly yellower
when bruised, odor slightly fragrant, taste mild.
Tubes adnate, near "massicot-yellow" (pale yellow) young, adnate
to decurrent, shallow (about 5-7 mm deep, but longer in very old basidiocarps). Pores minute, about 2-3 per mm when mature, pale "massicotyellow" (clear yellow); no color change when bruised.
Stipe 5-12 cm long, 10-15 mm at apex, equal or nearly so, solid,
yellowish within and near lemon-yellow in the cortex in upper part,
interior watery mottled, surface pallid and overlaid with brownish glandular dots above and below the bandlike annulus, base conspicuously
staining yellow where handled; annulus thick, soft, and readily collapsing, outer layer gelatinous, inner layer of soft floccose tissue.
Spore deposit dark cinnamon moist, or where smeared and dried,
olive-brown; spores 7-10 (11) X 3-4 j, smooth, subfusiform to narrowly
ellipsoid in face view, obscurely inequilateral in profile, pale greenish
yellow in KOH, pale tawny in Melzer's.
Basidia 4-spored, 20-26 X 5.5-7 x, narrowly clavate, hyaline in
KOH. Pleurocystidia scattered and at times with a slight amount of