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

BOLETUS

237

subtomentose, dried pilei rimulose near margin in large ones and unpolished in all; olive to honey-yellow, drying ochraceous to clay color,
NH40H brown on cuticle (no green or violet flash). Context firm,
yellowish, unchanging, odor and taste not distinctive.
Tubes up to 1 cm deep, olive-yellow, adnate; pores olive-yellow,
0.5-1.5 mm wide, unchanging when bruised.
Stipe 5-9 cm long, 8-15 mm at apex, equal or slightly enlarged
downward, solid, yellowish within, unchanging, buff color in dried
material; surface reticulate above with a wide-meshed reticulum having
poorly defined ridges, densely pruinose to subtomentose downward, the
ornamentation brownish to dull cinnamon against an ochraceous ground
color, these colors persisting in dried material, base with a yellow mycelium.
Spores 9-12 (13) X 3.5-4.5 u, smooth, lacking a distinct pore or
thin spot at apex, shape in face view narrowly elliptic to suboblong, in
profile obscurely inequilateral, the suprahilar area scarcely depressed in
many, color weakly olive-yellow in KOH, in Melzer's about the color of
the mounting medium, wall relatively thin.
Basidia 4-spored, 8-9 p broad, clavate, yellowish hyaline in KOH.
Pleurocystidia scattered, 36-48 X 9-12 j, fusoid-ventricose, obtuse to
subacute, thin-walled, smooth, hyaline in KOH and Melzer's. Cheilocystidia mostly small and more or less basidiole-like. Caulocystidia
abundant, 36-60 X 10-24 u, clavate to clavate-mucronate, thin-walled,
smooth, weakly yellow in KOH.
Tube trama of tubular hyphae 5-11 g wide, scarcely divergent as
revived in KOH and scarcely gelatinous, thin-walled. Pileus cuticle a
trichodermium of elements 9-16 (18) p wide, the cells often short and
inflated, end-cell often bullet-like, content colloidal in KOH, walls
smooth to slightly roughened, in Melzer's the cuticular hyphae appearing
nearly or quite smooth (lacking dextrinoid incrustations) and with
ochraceous content. Hyphae of subcutis and adjacent hyphae of the
context dingy orange-ochraceous in Melzer's and lacking dextrinoid incrustations. Clamp connections absent.
Habit, habitat, and distribution.-Gregarious in mixed woods, Mud
Lake Bog, Cheboygan County, July 4, 1968, collected by Mary Wells
(Smith 75480).
Observations.-In this species there was no change to blue when
bruised, there are no dextrinoid incrustations on the cuticular or subcuticular hyphae of the pileus, the spores are small, and many of the
cells in the trichodermial hyphae are inflated.