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

LECCINUM

171

the margin, in age at times rather conspicuously appressed fibrillosesquamulose, when old and wet the colors a dingy brownish orange.
Context thick, firm, pallid, when cut soon avellaneous changing to fuscous (lacking red tones in the change), odor and taste mild, FeSO4
bluish olive.
Tubes white becoming olivaceous-pallid and finally wood-brown,
depressed; pores minute, pallid, when lightly bruised staining olive,
staining avellaneous if severely bruised; pore surface where undamaged
often with an olivaceous sheen, at maturity duller.
Stipe 9-14 cm long, 1.5-2.5 cm thick, nearly equal, solid, slowly
fuscous in apex when cut (no other color change observed); surface with
coarse ornamentation which is pallid at first, then slowly becomes
reddish brown and by late maturity charcoal-black.
Spore deposit olive-brown moist, dingy snuff-brown as air-dried (a
dark yellow-brown); spores 12-15 X 3.8-5.2,, smooth, weakly yellowbrown in KOH and about the same in Melzer's, in face view obscurely
to distinctly fusoid, in profile somewhat inequilateral; wall slightly
thickened (-0.5 / thick), no apical pore present.
Basidia 4-spored, 30-38 X 9-12 u, clavate, hyaline in KOH and
nearly so in Melzer's. Pleurocystidia 35-50 X 9-15 /t, scattered, fusoidventricose with neck tapering to an acute apex, walls thin and smooth,
content of cells hyaline to weakly brownish (rarely) in KOH or Melzer's.
Cheilocystidia similar to pleurocystidia or smaller and some more or less
basidiole-like. Caulocystidia clavate to mucronate 10-30 A wide, length
variable, very few fusoid-ventricose cells present; walls thin and smooth,
content bister to snuff-brown as revived in KOH.
Tube trama subgelatinous, hyphae more or less tubular, smooth,
hyaline, thin-walled, diverging to subhymenium which is interwoven;
some oleiferous hyphae with dingy ochraceous content present (as
revived in KOH), in Melzer's the content nearly hyaline. Pileus trama of
hyaline thin-walled hyphae with more or less inflated cells, laticiferous
elements as in the tube trama, all hyphae hyaline to merely weakly
yellowish in Melzer's. Pileus cutis of a sparse surface layer of hyphae
with cells 10-25 (30) u broad, and varying from nearly globose to oval
to elongate, smooth or with a gelatinous layer causing irregularities in
the outline; terminal cells long- or short-bullet-shaped, pigment finely
granular in Melzer's. Hyphae of the subcutis hyaline in Melzer's or
merely yellowish. Clamp connections absent.
Habit, habitat, and distribution.-Gregarious under aspen-birch and
balsam, northeast corner of Otsego County, July 17, 1967, Smith
74568.