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

BOLETUS

273

age, often becoming areolate or rimose with age, colored "Morocco-red"
at very first, fading to "Acajou-red" to "brick-red" and in age "apricotbuff" or more or less orange-yellow. Context up to 3 cm thick, pale
yellowish, becoming blue when exposed, odor and taste not distinctive.
Tubes adnate to subdecurrent becoming depressed around the
stipe, 1-2 cm deep, "deep chrome" to "wax-yellow" (bright yellow) at
first, turning greenish blue where bruised; pores small (1-2 per mm),
round, yellow at first, greenish blue when bruised but in age often
orange to reddish especially after being bruised, but the color never as
pronounced as in the Luridi-and never present when the basidiocarps
are young.
Stipe 6-14 cm long, 1-4.5 cm thick, equal or nearly so, occasionally flared at the apex, often crooked, solid, yellow within, surface
dry, ridged with dots but not reticulate, bright yellow above, orange to
reddish brown lower down, or when young yellow all over but with a
pinkish bloom, somewhat longitudinally striate at first, pruinosity more
or less persistent, colors dingy in age.
Spore deposit brownish olive; spores (11) 12-16 (17) X (3) 4-5 u,
inequilateral in profile view, in face view narrowly fusiform, bright
yellow in KOH, very pale ochraceous-tawny in Melzer's, smooth, walls
slightly thickened, in Melzer's at first with a slight fleeting-amyloid
reaction.
Basidia 4-spored, 20-24 X 7-9., (rarely 2-spored), yellowish in
KOH and in Melzer's. Pleurocystidia scattered to abundant, almost imbedded, 28-40 X 6-12 /, fusoid-ventricose with acute apex, hyaline in
KOH, thin-walled, smooth, some clavate elements (30-35 X 12-15 u)
also present scattered through the hymenium. Cheilocystidia often
crowded, mostly clavate and with ochraceous to orange content revived
in KOH.
Tube trama of gelatinous divergent hyphae from a central strand.
Cuticle of pileus a more or less tangled hymeniform layer of clavate to
subfusoid cells 30-60 X 9-14 pg and with rich ochraceous content as
revived in KOH, the walls of the pedicel often up to 1 p thick and with
some pale yellow to hyaline incrusting material, some elements of the
cuticle typical of the trichodermial type of cutis. Context hyphae floccose, smooth, hyaline, interwoven. Clamp connections absent.
Habit, habitat, and distribution.-Gregarious and rather common in
open thin oak woods during wet weather in midsummer to early fall.
Rather common in the southeastern part of the state.
Observations.-The large spores distinguish this and B. bicoloroides
in the stirps. There is some gelatinization of the cuticular elements to