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

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THE BOLETES OF MICHIGAN

obtuse, smooth, thin-walled, content hyaline to yellowish in KOH. Tube
edges lined almost entirely with basidioles. Caulocystidia in fascicles,
2842 X 8-15 /., clavate, thin-walled, smooth, hyaline and "empty" in
KOH.
Tube trama of the Xerocomus subtype, yellowish in KOH but
fading as pigment diffuses into the mount. Pileus cuticle a trichodermium of tubular elements 6-9 (11) t wide, content yellow in
Melzer's, walls smooth to roughened, end-cells tubular and rounded at
apex, scattered, short, slightly inflated cells present in some of the elements. Hyphae of subcutis with conspicuous dextrinoid incrustations,
the hyphae merely with yellowish content in Melzer's. Clamp connections absent.
Habit, habitat, and distribution.-In a wet pasture under aspen
near a rotten log. Douglas Lake, Cheboygan County, June 23, 1968,
Smith 75298.
Observations.-The distinguishing features of this species are the
dull olive NH40H reaction on the pileus cuticle, lack of blue stains
when injured, small narrow spores, scurfy to pruinose stipe, elements of
pileus cuticle mostly of tubular cells, and the generally small size of the
basidiocarps.
124. Boletus alutaceus Morgan in Peck
Bull N. Y. State Mus. 2 (8):109. 1889
Xerocomus alutaceus (Morgan in Peck) Dick & Snell, Mycologia 53:228. 1961.
Pileus 5-10 cm broad, pulvinate becoming broadly convex to
nearly plane; surface dry and subpruinose (unpolished), even, tacky to
the touch in wet weather, cuticle slightly separable (but not gelatinous);
"pinkish cinnamon" to "cinnamon-buff" (pale tan with a reddish tint),
at first a duller yellow-brown ("Saccardo's umber" to "tawny-olive").
Context white with a reflection of pink near the cutis, 7-16 mm thick
at the stipe, unchanging when injured; odor and taste not distinctive.
Tubes about 6-15 mm long, whitish young becoming "pale olivebuff' or finally more olivaceous, depressed around the stipe, not changing to blue when injured; pores 1-1.5 mm broad, not stuffed when
young, olivaceous pallid but slowly brownish in age, stipe with thin
extensions of tube dissepiments down it for a short distance.
Stipe 6-8 cm long, 1-2 cm thick, straight or curved slightly, subequal, solid, pallid inside and out but context in older specimens changing to vinaceous-buff when cut (pale avellaneous); surface smooth, even