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

TYLOPIL US

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gin, sometimes surface near margin becoming pitted with age, color pale
to dark alutaceous to vinaceous-brown ("wood-brown" to "Veronabrown" when young), unchanging or becoming cinnamon ("cinnamonbrown" to "cinnamon-buff") with age, often with paler (pallid) margin.
Context very thick (up to 3 cm), white, unchanging or becoming pinkish
brown when exposed, often becoming discolored around the larval tunnels; odor none or occasionally slightly farinaceous, taste very bitter.
Tubes 1-2 cm deep, adnate to subdecurrent when young becoming
deeply depressed around the stipe with age, whitish to as dark as
"wood-brown" when young, soon becoming vinaceous to deep flesh
color ("light russet-vinaceous") in age, staining brownish ("cinnamon" to
"ochraceous-tawny") when bruised; pores at maturity about 1 mm in
diameter, whitish to dingy pallid when young, staining dingy brown
when bruised.
Stipe 4-10 cm long, rarely up to 20 cm or more long, 1-3 cm
thick at apex, rarely up to 6 cm thick below, clavate to bulbous, rarely
equal when young, becoming nearly equal to ventricose or remaining
bulbous to clavate, typically reticulate especially over the upper portion,
often smooth lower down, at times the reticulation prominent over most
of its length, solid, firm, dry, fleshy, usually pallid upward and becoming pale brown or alutaceous to darker below, often with olivaceous
stains from handling.
Spore deposit deep vinaceous; spores 11-15 (17) X 3-5 At, narrowly
subfusoid in face view, in profile somewhat inequilateral; smooth,
hyaline or nearly so in KOH, yellowish in Melzer's, strongly dextrinoid
when fresh.
Basidia 4-spored, 18-24 X 8-10,, hyaline in KOH, yellowish in
Melzer's. Pleurocystidia numerous to abundant, prominently projecting,
36-50 X 8-14 u, fusoid-ventricose with subacute to submucronate or
tapered to an acute apex, thin-walled, content hyaline to frequently
bister or yellowish in KOH, in Melzer's often dark red to reddish brown
(dextrinoid), the content granular. Cheilocystidia often crowded, similar
to the pleurocystidia or neck less developed. Tube trama divergent and
gelatinous from a central strand, hyphae nonamyloid in all parts.
Pileus cuticle a trichodermium of matted hyphae 4-7,u wide, yellow in KOH, tubular, the cells elongate, nonamyloid both as to wall and
content. Context of floccose, interwoven, hyaline hyphae broader than
in the cuticle, no incrustations seen, all hyphae nonamyloid. Clamp connections absent.
Habit, habitat, and distribution.-Solitary to gregarious or rarely in
large clusters, on rotten debris of hemlock and on humus in conifer