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

BOLETUS

257

Observations. -European specimens examined have the dextrinoid
incrustations on the hyphae of the subcutis, but they are often limited
to certain areas. In American specimens they are much more numerous.
The NH40H reaction to green will distinguish B. spadiceus and B.
illudens from B. subtomentosus.
133a. Boletus subtomentosus var. perplexus Smith &
Thiers, var. nov.
Illus. P1. 103 (lower).
Pileus 3-6 cm latus, demum planus, siccus, subtomentosus, olivaceus vel olivaceo-ochraceus, tarde olivaceo-brunneus. Contextus pallide
luteus, immutabilis. Tubuli olivaceo-lutei; pori 1-2 per mm,lutei tactu
olivaceo-caerulei. Stipes 4-6 cm longus, 8-12 mm crassus, pruinosus;
pruina roseo-cinnamomea. Sporae 11-14 X 4-5,. Typus Smith 74476
(MICH).
Pileus 3-6 cm broad, convex, expanding to plane; surface dry and
tomentose to plushlike, dry, olive to olive-ochraceous ("Isabella color")
or dingy olive-brown finally, margin even. Context weakly yellow-buff
to ivory-yellow (yellowish white), lacking a distinct line at the tubes,
not staining blue when injured, with a dark olive-brown line just under
the cutis; odor and taste mild.
Tubes 8-12 mm deep, broadly adnate to decurrent, "Isabella
color" (olive yellowish) or more olivaceous, unchanging when cut; pores
1-2 per mm, yellow becoming olive-yellow and when bruised readily
staining olive-blue.
Stipe 4-6 cm long, 8-12 mm thick, equal, solid, greenish pallid
within including the base, brownish around wormholes, surface covered
more or less overall with a reddish cinnamon pruina, base with a thin
coating of pallid mycelium.
Spore deposit olivaceous; spores 11-14 X 4-5,, smooth, wall
-0.5 i thick, apex lacking a pore; shape in profile somewhat inequilateral, in face view narrowly subelliptic, dull yellow-brown in KOH,
about the same in Melzer's. Caulocystidia clavate, 26-38 X 9-15 JL, thinwalled, smooth, with a yellow content diffusing into the mount as revived in KOH, hardly distinct from basidioles.
Pileus cuticle a trichodermium of nongelatinous hyphae 5-15 j,
wide, tubular or nearly so, with many short cells in the elements that
are 15-30 t long, walls smooth to roughened slightly, with a yellow
content diffusing into the mounts as revived in KOH, as mounted in