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

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THE BOLETES OF MICHIGAN

Herb. Univ. Mich. conservatum est; prope Waterloo, Washtenaw County,
September 5, 1965, legit Florence Hoseney (Smith 72503).
Pileus 5-6 cm broad, plane; surface moist and subhygrophanous
becoming slightly rimose in age, color "mikado-brown" to "orangecinnamon" (bright orange-brown to orange-cinnamon), when dried a
dingy olivaceous-brown. Context slightly acid to the taste, yellow near
tubes and with an olive line just above the tubes, dingy vinaceous in the
central part and near the cuticle as well as in apex of stipe, pale lemonyellow in base of stipe, not changing to blue when cut or bruised; with
FeSO4 no reaction on the pileus context, on base of stipe bright olive
to olive-fuscous.
Tubes up to 1 cm long, greenish yellow and drying olivaceous,
slightly depressed but decurrent down the apex of the stipe; pores about
1 mm wide, greenish yellow and unchanging when bruised.
Stipe 6-7 long, 10-12 mm at apex, tapered downward, solid (for
color of context see above); surface even, apex bright yellow, with lines
from tubes extending down a short distance but not reticulate, base dull
vinaceous-red and unpolished.
Spore deposit dull olivaceous; spores (13) 14-17 X 4-5.5 g,
smooth, no apical pore evident, shape in face view boat-shaped to
fusoid, in profile narrowly somewhat inequilateral but suprahilar depression shallow, ochraceous in KOH, ochraceous-tan in Melzer's,
amyloid when fresh but soon fading.
Basidia 4-spored, 23-30 X 7-11 p, short- to long-clavate, hyaline in
KOH, pale yellowish in Melzer's. Pleurocystidia and cheilocystidia-none
found. Tube trama of the bilateral type but hyphal divergence only
moderately prominent, all hyphae hyaline and smooth.
Pileus cutis a poorly formed layer of clavate to versiform cells in a
weak palisade which collapses in age, some cells up to 20 j, wide, some
globose and of various sizes, all thin-walled, smooth, and with ochraceous content in KOH, merely yellowish in Melzer's. Context hyphae
merely yellowish in Melzer's; many large hyaline to yellowish droplets
present in mounts in Melzer's. Clamp connections absent.
Habit, habitat, and distribution.-Gregarious in sandy soil, Waterloo Recreation Area, Washtenaw County, September 5, 1965, collected
by Florence Hoseney (Smith 72503).
Observations.-Many hyphal cells in the pileus are over 20 p wide
and collapse readily. To this extent the structure of the pileus differs
from that of other species in the group. The tubes separate when the
pileus is broken downward, but in spite of this the species appears
closely related to B. illudens. It differs in having a more olivaceous