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

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THE BOLETES OF MICHIGAN

showing none or a very faint one, in KOH pale bister (dingy yellowbrown), in face view suboblong to somewhat boat-shaped, or ventricose
in largest spores, in profile inequilateral-elongate and with a pronounced
suprahilar depression, on larger spores and those most highly colored
often ventricose-inequilateral, wall about 0.5 p thick.
Basidia 4-spored, 28-45 X 10-15 ju, yellowish in KOH or Melzer's,
clavate. Pleurocystidia scattered, 36-55 X 9-15 p, fusoid-ventricose and
with a tapering neck to a subacute apex, thin-walled, readily collapsing,
content yellowish to hyaline in either Melzer's or KOH. Cheilocystidia
similar to pleurocystidia varying to merely obtusely fusoid-ventricose
and smaller. Caulocystidia in patches, clavate to clavate-mucronate,
fusoid-ventricose to lanceolate, 32-60 X 8-17 J, also some flexuous filaments 4-6 p in diameter in the patches of caulohymenium; content of
all types either hyaline or yellowish to brownish in KOH.
Tube trama of subgelatinous hyphae nearly parallel in arrangement
but slightly diverging to subhymenium; laticiferous elements 5-9 p wide
also present. Pileus trichodermium of hyphae with heavily brownincrusted walls from plates, zones or spirals of incrusting material; the
hyphae 8-15 p wide with the 24 cells back from the end-cell inflated
and 14-20 p wide but not globose, end-cell short and cystidioid, some
divided by a secondary septum into an inflated cell and a tapered tipcell, cell content not distinctive in either KOH or Melzer's. Hyphae of
the subcutis also heavily incrusted, 4-10 p wide, lacking distinctive content in either KOH or Melzer's. Context hyphae smooth, thin-walled,
content not distinctive in Melzer's; laticiferous elements numerous,
yellowish in Melzer's. Clamp connections none found.
Habit, habitat, and distribution.-Gregarious under hardwoods,
Highlands Recreation Area, Oakland County, August 26, 1966, collected
by Patricia Mazzer, for whom it is named (Smith 73236-type).
Observations.-This species differs from B. truncatus in the olive
mycelium around the base of the stipe, the disagreeable taste, and in the
distinctly cystidioid heavily incrusted terminal cells of the trichodermial
elements. The pileus (and some basidiocarps were old) did not become
areolate as in B. truncatus, which is almost always areolate by maturity.
We have not noted a change to rose on the context of B. truncatus after
the blue fades, but in view of the general tendency of that species to
develop red we do not emphasize the change noted for B. patriciae. B.
porosporus Imler is perhaps the most similar bolete. It apparently lacks a
bitter taste, the mycelium around the base of the stipe is slightly grayer,
and the cap becomes areolate.