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

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THE BOLETES OF MICHIGAN

woods or in woods of hardwoods. It is one of the very common late
summer boletes in the state.
Observations.-In the past this species has been confused with T.
rubrobrunneus as a "form" with reticulation only at the stipe apex.
Both develop olive to olive-brown stains on the stipe from handling, and
both are very bitter. Mild tasting boletes of similar appearance are most
likely to be T. indecisus or T. ferrugineus (if the two are distinct). In T.
felleus the reticulation is raised and conspicuous. In Shaffer 4888 from
France the content of the pleurocystidia is granular and ochraceous in
KOH but in Melzer's is deep red to reddish brown. In var. obesus Peck,
as revived in KOH the content of the cystidia is homogeneous.
Material examined.-Alger: Mains 32-103; Smith 9-19-29. Barry:
Smith 73227, 73297. Cheboygan: Chmieleweski 70, 100; Shaffer 1447;
Smith 25983; Thiers 3097, 3610, 3830, 3968, 4203. Chippewa: Smith
71892. Crawford: Thiers 3398. Emmet: Smith 57399, 62965, 63043,
71859, 74703; Thiers 903, 3230, 3528, 3710, 4414. Gratiot: Potter
3507, 9909b, 12299, 13939. Luce: Smith 37294, 37821, 39310, 67156,
71877, 72867; Thiers 3332. Marquette: Bartelli 2520, 2524. Montcalm:
Potter 13186. Oakland: Smith 6401, 6574, 6777. Ontonagon: Shaffer
3744. Washtenaw: Kauffman 1905; Smith 1509, 62673, 64570; Thiers
4605.
50a. Tylopilus felleus var. uliginosus, var. nov.
A typo differt: Cystidia in "KOH" cum globulis rotundis. Typus
Smith 72709 (MICH).
Pileus 5-10 cm broad, broadly convex, margin even, surface
minutely areolate overall-rather conspicuous in dried pileus, dull
leather-brown and when dried near sepia. Context thick, pallid, dingy
brownish where cut and as dried grayish brown on fractured surfaces.
Tubes about 1 cm deep, adnate; pallid to whitish, becoming vinaceous when mature, pores 1-2 per mm, staining brownish slightly when
injured.
Stipe 5-7 cm long, 12-18 mm thick at apex, enlarged downward,
solid; surface conspicuously reticulate to base and as dried the lines of
the reticulum blackish, near base dingy yellow-brown and becoming
darker from handling, paler brownish above and discoloring to olivaceous on standing.
Spores 13-17 (18) X 4-5 u, smooth, nearly hyaline in KOH, tawny
in Melzer's, no apical differentiation; in profile narrowly inequilateral
and "sway-backed," in face view subfusiform, wall relatively thin.