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

FUSCOBOLETINUS

89

and toward margin "orange-cinnamon" (pale reddish cinnamon), disc
pinkish cinnamon in age and margin darker (vinaceous-brown-"Veronabrown"). Context 9-10 mm thick above edge of stipe, yellow or orange
around larval tunnels, unchanging when cut, with a nondistinctive odor
and a pleasant taste.
Tubes adnate to stipe, 1.5-4 mm wide, white at first becoming
yellowish, unchanging when cut; pores angular and irregular in shape,
sometimes compound, more or less radially arranged but not elongated
radially, when young yellowish (paler than "light buff' to "cream
color"), becoming more ochraceous in age, unchanging when injured,
with prominent vinaceous-brown glandular dots.
Stipe 4-8.2 cm long, 9-15 mm thick at the apex, usually tapering
downward (but at times enlarged to 25 mm thick) just above the
middle; with "mikado-brown" (vinaceous-brown) glandular dots, tan but
at times staining yellow at the base where bruised, with white to bright
yellow mycelium at the base and in surrounding soil, sometimes with
yellow context in the base. Veil fibrillose to cottony, white to yellowish, sheathing lower part of stipe when young and also covering the
hymenophore, not forming an annulus and remains over lower part of
stipe eventually evanescent.
Spore deposit moist "avellaneous" to near "cacao-brown," with
loss of moisture "deep brownish drab" (purplish brown); spores
6.7-8 X 2.7-3.2 p, in face view oblong to narrowly ovate, narrowly ovate
in profile, smooth, in Melzer's moderately to strongly dextrinoid.
Basidia 20-29 X 4-7 u, usually clavate, 4-spored, in KOH hyaline
or near the pleurocystidia some with colored content. Pleurocystidia
usually in clusters, individual cystidia 20-60 X 3.3-9.6u, the shorter
ones not projecting beyond the basidia, usually clavate, at times subcylindric to subfusoid, hyaline at first (in water or KOH) as revived in
KOH bister or with bister incrusting pigment, thin-walled. Cheilocystidia
like the pleurocystidia.
Tube trama bilateral; subhymenium indistinct and prosenchymatous.
Pileus cuticle 400-700 p thick; an ixotrichodcrm of gelatinous, septate,
rarely branched hyphae 2.5-7.5 p in diameter, densely incrusted with
minute refractive particles. Caulocystidia resembling pleurocystidia but
larger. Clamp connections absent.
Habit, habitat, and distribution.-Scattered to cespitose on humus
in sandy soil of a mixed woods (Quercus, Populus, Betula, and Pinus
species), known only from Minnesota, but included here because it is an
obvious element of the western Great Lakes fungous flora.