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

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THE BOLETES OF MICHIGAN

colored vinaceous by the spores; pores small and round at first, 1-2 per
mm when mature, dingy brownish becoming pallid, staining dingy brown
when bruised.
Stipe (6) 8-20 cm long, 1-5 cm thick at apex, up to 8 cm at the
base in large specimens, clavate becoming equal, solid, white within but
staining olive around larval tunnels at times; surface not reticulate or
only obscurely so at very apex, whitish to pallid above, vinaceous-brown
below but base whitish; surface often staining olivaceous from handling
and base near groundline often dingy olive-brown in age.
Spore deposit "russet-vinaceous" (dark vinaceous-red); spores
10-14 X 3-4.5 i, smooth, walls thin to scarcely thickened, in profile
narrowly inequilateral with a distinct suprahilar depression, in face view
suboblong to narrowly and obscurely fusoid, nearly hyaline in KOH, in
Melzer's pale tan with occasional individuals dark red-brown (dextrinoid).
Basidia 20-26 X 8-11 gi, 4-spored, hyaline in KOH, short-clavate.
Pleurocystidia abundant to scattered, 36-52 X 9-14 ji, ventricose in basal
half, apical half a narrow (3-4 i in diameter) neck ending in a subacute
apex, as revived in KOH with an amorphous granular-refractive content
(resembling that of chrysocystidia only occupying more of the cell content), this content dark reddish brown in Melzer's,(dextrinoid).
Tube trama of hyphae divergent from a central strand, but at
maturity nearly parallel, hyaline, thin-walled, smooth, not gelatinous as
revived in KOH.
Cuticle of pileus a tangled trichodermium of hyphae pale cinnamon as revived in KOH, with smooth walls, narrow (4-6 i), with
end-cells slightly enlarged to 6-9 u near the apex, all hyphae nonamyloid. Clamp connections absent.
Habit, habitat, and distribution.-Scattered, gregarious, or cespitose
in open woods on thin sandy soil, with us mostly under second-growth
oak, very abundant after heavy rains in the summer and early fall in the
southern part of the state.
Observations.-A feature of this species along with several others in
this genus is that apparently as revived in Melzer's the content of the
cystidium becomes viscous to some degree because one often finds
globules of orange-red pigment present in the mounts just as one observes them for most species of Rhizopogon.
We have one collection (Smith 72734) from the Highlands Recreation Area, Livingston County, September 29, 1965, in which the pores
were cinnamon-brown at all stages, even when the sides were perfectly
white. The pileus was about "Sayal-brown" (a dull cinnamon), the taste
was very bitter, the apex of the stipe slightly reticulate, the spores
10-13 X 3-3.5 I but with a fair number 12-15 X 5-6 u, and the pleuro