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

BOLETUS

241

or at times with lines or faint reticulations from extensions of the tubes,
generally becoming dingy brownish from handling.
Spores 9-12 (13) X 4-5 g, suboblong in face view, slightly inequilateral in profile, smooth, wall slightly thickened, nearly lemon-yellow in
KOH, in Melzer's pale dingy yellow-brown (not dextrinoid).
Basidia 26-32 X 8-9 p, 4-spored, clavate, yellow in KOH and
Melzer's. Pleurocystidia scattered, 33-45 X 9-14 #, clavate to fusoidventricose with obtuse apex, content often dingy yellow as revived in
KOH, in Melzer's merely dingy yellow-brown.
Tube trama of hyaline gelatinous hyphae somewhat divergent to
the subhymenium. Pileus cuticle a tangled layer of hyphae 3-6 A# wide,
the end-cells tubular or nearly so and blunt at apex. Context hyphae
8-15 H wide, hyaline, smooth, thin-walled, hyaline to yellowish in KOH,
in Melzer's orange-brown. Clamp connections extremely rare. No amyloid debris present or no fleeting-amyloid reactions evident.
Habit, habitat, and distribution.-On swampy ground, Saline, Washtenaw County, July 18, 1922, C. H. Kauffman. Apparently, the species
is very rare in Michigan.
Observations.-The tube color as indicated in Kauffman's notes
was more olive than yellow, but a strong yellow cast is present in the
dried specimens. This is a nondescript bolete which in mature stages or
when dried might be confused with B. pallidus, but it does not stain
blue and is not whitish when young. The hyphae of the context react in
Melzer's similarly to those of B. roxanae.
Stirps ILLUDENS
B. spadiceus, which at times lacks a change to blue on bruising,
may be sought for here also, but see subsection Subtomentosi.
KEY
1. Spores (13) 14-17 x 4-5.5 lI; pileus vinaceous-brown or orange-cinnamon.........................................B. hoseneae
1. Spores 10-14, long and pileus differently colored................ 2
2. Pores 1-2 per mm at maturity.......................... 3
2. Pores 1-2 mm wide at maturity......................... 4
3. Terminal cells of trichodermial elements often globose to dumbbellshaped................................. B. brunneocitrinus
3. Terminal cells of trichodermial elements mostly bullet-shaped to cystidioid..................................... see B. minutiporus
4. NH40H on pileus cuticle Paris-green then brown.......... B. illudens
4. NH40H on pileus cuticle purple then darkening......... B. nancyae