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

BOLETUS

285

material moistened with alcohol and then water. In Melzer's the hymenial tissue is bluish black when first revived. It is possible that the
fleeting-amyloid reaction of this species is merely associated with the
change to blue on moistening of the dried hymenophoral tissue in pure
chloral hydrate. The following description is based on Peck's original
and Smith's study of the type:
"Pileus at first firm, convex, pruinose-tomentose, brick red, then
expanded, paler or ochraceous-red, glabrous, soft; tubes at first plane or
concave, bright yellow, then tinged with green, finally sordid-yellow,
small, subrotund; stem firm, smooth, lemon-yellow, narrowed at the top
when young, and sometimes slightly fibrose from the decurrent walls of
the tubes, often stained with red or rhubarb color; spores greenish
brown,.0005' long,.00016' broad; flesh of the pileus pale yellow, of
the stem brighter colored and marbled, both flesh and tubes quickly
changing to blue when wounded.
"Plant scattered to caespitose, 4'-6' high, pileus 3'-8' broad, stem
6'-12' thick."
Spores 10-13 (15) X 3-4.5 #, smooth, lacking a pore or thin-spot
at apex, in shape suboblong to subfusiform in face view, in profile obscurely inequilateral to suboblong, color in KOH ochraceous, in Melzer's
ochraceous to pale clay color, wall about 0.2 Ju thick.
Basidia 4-spored, 25-33 X 7-9 u, narrowly clavate, hyaline in
KOH. Pleurocystidia 33-45 X 9-13 g, fusoid-ventricose, the neck 3-4 p
wide and apex subacute, walls thin, smooth and hyaline, content yellowish to hyaline in either KOH or Melzer's. Cheilocystidia smaller than
pleurocystidia and varying to basidiole-like in shape. Hymenial tissue
mounted in Melzer's merely ochraceous to brownish.
Tube trama of the Boletussubtype, hyphae tubular and 4-8 I
wide, lacking any amyloid reaction, broad (up to 12 j), laticiferous elements present and ochraceous in KOH or Melzer's. Pileus cutis a tangle
of more or less appressed hyphae 4-8 u wide, the walls smooth and thin,
the content ochraceous in KOH, and in Melzer's orange-ochraceous, pigment globules not forming; cells tubular and mostly long, end-cells tubular to slightly clavate or cystidioid. Hyphae of subcutis and context only
weakly ochraceous in Melzer's. Clamp connections none.
Observations.-Both B. sensibilis and B. miniato-olivaceus have very
friable context-it almost crumbles when one attempts to section it. We
assume that the fleeting-amyloid reaction is lost after basidiocarps have
stood for years in an herbarium. This needs to be verified, but only time
will tell. Previous to our study this species and B. miniato-olivaceus were
hopelessly confused-starting from the time of Peck himself.
Material examined.-Cheboygan: Smith 63754, 63759, 63779,
63854.