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

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THE BOLETES OF MICHIGAN

typically becoming scabrous but often not strongly or conspicuously so
in age, scales white when young, typically becoming darker with age or
when handled but still pale colored when compared with the genus as a
whole, solid, white within, unchanging.
Spores (10) 15-20 (24) X 4-6 g, smooth, in face view cylindric to
subfusiform, in profile somewhat elongate-inequilateral, pale yellow revived in KOH, with a moderately thick wall (-0.5 pA).
Basidia 4-spored, 21-26 X 9-12 I, clavate, hyaline in KOH. Pleurocystidia scattered to numerous, 30-48 X 7-12 LI, more abundant near the
pores, often difficult to locate in old basidiocarps, hyaline, thin-walled,
versiform-aciculate, clavate, with elongated, tapered, distal portion, subcylindric or fusoid-ventricose.
Hymenophoral trama obscurely divergent to subparallel, hyaline in
KOH and Melzer's. Pileus cuticle more or less of upright hyphae forming
a trichodermium but composed of globose to pyriform cells, these disarticulating with age and disappearing leaving a glabrous pileus. Cuticle of
stipe differentiated as a layer of loosely interwoven hyphae, the filaments with occasionally upright tips with inflated cells similar to those
of the pileus trichodermium, hyaline in KOH or Melzer's. Clamp connections absent.
Habit, habitat, and distribution.-This is a common species of the
Gulf Region not yet with an authentic record from Michigan.
Observations.-One reason for including this species here is to get
records and complete studies of it and other variants since many of the
Gulf Coast fungi occur rarely in Michigan. Singer (1947) described 2
forms, f. reticulatum having an alveolate-reticulate pileus which becomes
slightly viscid, and f. epiphaeum having an olive-gray pileus becoming
rimose-tessellate in age.
110. Leccinum griseum (Quelet) Singer
Rohrlinge II. In Pilze Mitteleuropas p. 89. 1967
Gyroporus griseus Quelet, Assoc. Fr. Avanc. Sci. (1901):496. 1902.
Illus. P1. 90.
Pileus 3-9 cm broad, obtuse to convex becoming broadly convex or
with a low broad umbo, at times nearly plane, margin not extending
beyond the tubes, glabrous at first and often conspicuously rugulosepitted, eventually areolate (particularly when dried) as in Boletus
chrysenteron and then the areolae appearing subtomentose, pallid context showing in the cracks, dingy yellow-brown ("snuff-brown" to