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

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THE BOLETES OF MICHIGAN

some European authors. However, Secretan (1833) described the species
as having colored pores. Singer (1967), however, described the species
with yellowish tubes and pores. We have as yet not found a large-spored
taxon with truly yellowish tubes in North America. The colored pores
clearly distinguish Secretan's species from B. porphyrosporus Fries. Fries
stated: "Poris amplis, pentagonis, griseis, tactu umbrinus" (1874, p.
514). Hence a species with dark coffee-colored pores when young cannot legitimately be assigned here, and we do not accept the synonymy
generally given in the literature. For further comment see T. prophyrosporus.
41. Tylopilus porphyrosporus (Fries), comb. nov.
Boletus porphyrosporus Fries, Bolet. Fung. Gen. N. 36, 1835.
Illus. Pls. 4849.
Pileus 4-7 cm broad, broadly convex, the margin even, surface dry
and subvelvety, the pile becoming matted down, very dark dull brown
(olive-brown) slowly changing to drab but when properly dried with a
distinct ochraceous undertone. Context pallid, slowly changing to
fuscous on cut surface, odor acid-disagreeable, taste mild, with NH40H
on cutis dull reddish to reddish brown, the same color with KOH; with
FeS04 on cut surface of context distinctly olive.
Tubes nearly free, sharply depressed around the stipe, dark dull
cocoa color, about 10 mm long, when cut the sides soon wood-brown;
pores staining dark chocolate color when bruised (no blue stain developing), concolorous with the sides when young.
Stipe 4-7 cm long, 1 cm thick, solid, staining fuscous within;
surface pruinose to punctate with the ornamentation colored like the
pileus, pallid below but soon stained fuscous from handling.
Spore deposit chocolate-gray ("wood-brown"). Spores 13-17 X
6-8 p, smooth, lacking an apical pore, as revived in KOH cinnamonbrown, paler yellowish brown in Melzer's, shape in face view oval to
narrowly elliptic or subfusoid, in profile rather obscurely inequilateral,
the suprahilar area mostly merely flattened.
Basidia 26-35 X 9-12 l, clavate, yellowish in KOH but slowly
becoming hyaline, merely hyaline in Melzer's. Pleurocystidia scattered,
38-64 X 10-16,, broadly ventricose with a narrow flexuous neck and
subacute apex, thin-walled, smooth, content revived in KOH yellowish
to nearly hyaline, when revived in Melzer's bister to dark sepia-brown
and stringy to granular. Cheilocystidia mostly resembling basidioles.
Tube trama of the Boletus subtype. Pileus cutis a layer of tangled