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

APPENDIX

403

Pileus cuticle a matted layer of fibrils showing no indications of
trichodermial structure, the end-cells of the hyphae narrowly cystidioid,
4-8, wide, and walls smooth to roughened lightly by adhering slime (?),
the matrical hyphae 3-7 iu broad and not distinctively colored in either
KOH or Melzer's. Subcuticular hyphae weakly yellow in Melzer's. Clamp
connections absent.
Notes. Murrill thought it might be a synonym of B. inflexus, but
that is out of the question on the basis of the microscopic characters. It
is very close to B. roxanae, but the latter has wider cuticular hyphae,
However, this character deserves further study from a larger sample of
specimens. For the present we recognize B. multipunctus as a species
close to B. roxanae but as yet not recognized from Michigan.
Boletus scabroides Kauffman in Snell, Mycologia 28:472. 1936
Illus. Figs. 90-93.
Pileus convex to plane, 6-10 cm broad; surface slightly viscid when
fresh, even, glabrous, minutely rimose in spots; pale tan, ochraceouscinnamon or brown-ochraceous. Flesh soft, whitish to pale yellowish,
changing slightly to bluish or changing not at all; taste and odor mild,
except surface bitter. Tubes adnate, becoming depressed and half adnate,
as long as the flesh is thick; greenish yellow becoming sordid greenish
yellow in age, scarcely changing to blue; mouths angular, some more or
less compound, 1-2 mm. Stipe even to somewhat striate, tending toward
reticulate, minutely furfuraceous to scurfy or minutely scabrous except
at apex; citron-yellow at apex and chrome-yellow at base, in between
pallid tinged brownish or perhaps mostly yellow tinged reddish, with
scurf sometimes reddish; within yellow, changing very slowly to pale
blue; 5-9 cm long, 6-20 mm thick. Spores very pale greenish yellow
under the microscope (in old specimens), subfusiform, 11-15 X 3.5-5 ji,
some to 18 iu, mostly 12-14 X 3.5-4.5,.
Type study. Spores 13-16.5 X 3.5-4.5,u, smooth, lacking an apical
pore, shape in face view elongate-fusiform, in profile elongate-inequilateral, the suprahilar depression broad and pronounced, color in KOH
yellowish to yellowish hyaline, in Melzer's pale tan, wall -0.2 y thick, no
sign of any amyloid or fleeting-amyloid reaction seen.
Basidia 4-spored, clavate, 8-9 Mu broad, yellowish to hyaline in
KOH. Pleurocystidia-none observed. Cheilocystidia not studied (edge of
tubes in poor condition). Caulocystidia 30-50 X 8-25,u, clavate to vesiculose, thin-walled, content not distinctive in KOH.