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

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THE BOLETES OF MICHIGAN

3. Hyphae of pileus subcutis lacking dextrinoid incrustations (rusty brown)
in Melzer's............................... B. tomentosulus
3. Dextrinoid incrustations present........................... 4
4. Elements of pileus trichodermium with red content as viewed in
Melzer's (using dried material)...................B. subparvulus
4. Not as above.................................... 5
5. Pileus cuticle with hyphae having many short cells (15-30, long); pileus
2-6 cm wide..................... B. subtomentosus var. perplexus
5. Pileus cuticle lacking a significant number of short cells in the elements
of the trichodermium; pileus 4-12 cm or more wide...................................... B. subtomentosus var. subtomentosus
131. Boletus tomentosulus Smith & Thiers, sp. nov.
Pileus circa 12 cm latus, late convexus, ochraceo-luteus, siccus,
granuloso-rimulosus. Contextus albus, tactu caeruleus. Tubuli 8-12 mm
longi, ochraceo-lutei tactu caerulei; pori 1-1.5 mm lati. Stipes circa 6 cm
longus, 17 mm crassus, costatus, subluteus. Sporae 11-14 X 3.8-4.8gl.
Specimen typicum in Herb. Univ. Mich. conservatum est; prope Harbor
Springs, Emmet County, July 1, 1967, legit Smith 74383.
Pileus about 12 cm broad, broadly convex; surface dry and granulose-rimulose, yellow-ocher overall and drying with a strong ochraceous
tone, margin even. Context white, becoming weakly yellowish in drying,
staining blue near the tubes when cut, the fresh cutis merely brownish
with NH40H and the same reaction with KOH.
Tubes shallow (8 mm deep in a 12 cm pileus), decurrent, evenly
about ocher-yellow (almost concolorous with the pileus), staining blue
when cut; pores wide, 1-1.5 mm, yellow, staining blue when injured.
Stipe 6 cm long, 17 mm thick, solid, narrowed below, yellow
within down to the basal area which is dingy cinnamon (but it dries an
even color throughout); surface coarsely reticulate to longitudinally
ribbed, neither distinctly fibrillose nor pruinose, yellow except for
pinkish base which is partly covered by yellow mycelium.
Spores 11-14 X 3.8-4.8 u, smooth, ochraceous in KOH, duller in
Melzer's and with a distinct "fleeting-amyloid" reaction; in profile
elongate-inequilateral, in face view subfusoid, wall about 0.2 l thick.
Basidia 4-spored. Pleurocystidia scattered, 33-47 X 8-13 u, subfusoid, hyaline, smooth, thin-walled. Pileus cutis a trichodermium of
hyphae 6-15, wide and with inflated cells in some of the hyphae up to
20 l broad, the cells not infrequently short-ellipsoid to subglobose, walls
smooth, all contents colloidal and yellowish in KOH but soon fading,
yellowish in Melzer's; subcutis of interwoven hyphae yellow in Melzer's