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

FUSCOBOLETINUS

87

we believe, was the first to describe it. The color change reminds one of
that of Leccinum insigne. On the pore edges the basidia (with sterigmata) as well as the cystidia may be colored. Frost mentioned the
overhanging margin, the "sordid brown" color and the changing context.
36. Fuscoboletinus grisellus (Peck) Pomerleau & Smith
Brittonia 14:168. 1962
Boletinus grisellus (Peck), Mem. N. Y. State Mus. 3:169. 1900.
Illus. P1. 43.
Pileus 3-8 cm broad, obtuse to broadly conic, then expanding to
nearly plane; surface appressed-fibrillose to slightly hairy-squamulose,
viscid beneath the fibrils when fresh, pale dull olive, becoming pallid to
grayish olivaceous or occasionally tinted with yellow, avellaneous in age
at times drying dull brown; margin inrolled when young, frequently
decorated with remnants of the submembranous grayish pallid veil. Context thickish, cottony, whitish to faintly olivaceous; odor and taste
slight not distinctive, white, unchanging when- cut, bluish gray with
FeS04.
Tubes 3-6 mm long, adnate to decurrent, scarcely separable, pallid
to grayish or finally dull brownish; pores concolorous with sides, round
to angular, or long and narrow near the stipe (sublamellate), typically
boletinoid with radiating lines at maturity.
Stipe short, (2) 3-8 cm long, 0.5-1.5 cm, thick, equal, straight,
solid, whitish within near apex, bright yellow in the base; surface
whitish to pallid, becoming yellowish, rarely somewhat bluish where
handled; somewhat reticulate at times above the annulus or veil zone
from the tubes, somewhat squamulose to nearly glabrous below the
annular zone; veil submembranous, seldom leaving a well-formed annulus.
Spore deposit gray-brown to chocolate-gray; spores 8-10
(11.5) X 4.3-4.8 (5) i, smooth, in face view elliptic to narrowly ovate,
in profile inequilateral, suprahilar depression shallow; wall somewhat
thickened, in KOH hyaline to pale fuscous, in Melzer's yellowish to pale
tawny.
Basidia pale fuscous brown in KOH, 24-27 X 5-7 j, narrowly
clavate. Pleurocystidia mostly in clusters, 40-60 X 5-7,u, emerging up to
50 S beyond the hymenium, subcylindric, hyaline or with dull brown
content in KOH, incrusted around the base of the clusters with dark