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

FUSCOBOLETINUS

81

Tubes subdecurrent to decurrent, separable from the context,
4-8 mm thick, brilliant yellow when young, duller yellow at maturity and often changing to olivaceous or "cinnamon-buff' in age;
pores concolorous, angular, compound, and irregular in size and shape,
up to 2 mm wide, typically boletinoid with radial lines, finely hairy
when young under a lens, becoming spotted with small brownish black
dots on the sides when old from discolored bunches of pleurocystidia.
Stipe 4-8 cm long, 8-15 mm thick, subcylindric and gradually
tapered downward, without glandules, annulate, reticulate and bright
yellow above and occasionally reddish punctate, smooth below and
slimy yellow with reddish dots at first, becoming deep red to chestnut
without flavous tones showing through the dingy colored sheath below
the annulus; base yellow; context yellow and unchanging when exposed;
annulus slimy and thick at first, collapsing and in age inconspicuous,
deep red when young, becoming blackish brown in age; thin inner veil
fibrillose and evident at times as patches which darken in age.
Spore deposit dull purplish drab or deep purple-brown; spores
7.5-11.5 X 3.5-5 I, narrowly oblong in face view, inequilateral in profile,
slightly depressed above the inconspicuous hilar appendage and narrowed
toward the apex, smooth; wall slightly thickened, nearly hyaline in
KOH, yellowish in Melzer's.
Basidia 26-30 X 7-9 u, 4-spored. Pleurocystidia numerous in dense
fascicles 30-50 u in diameter, with bister incrusting material (as revived
in KOH) surrounding the basal portion and forming purple-brown drops
in Melzer's; individual cystidia subcylindric, 40-60 X 4-7 J, thin-walled,
the content hyaline to dull brown. Cheilocystidia similar to pleurocystidia.
Tube trama gelatinous, somewhat divergent from a floccose central strand, nonamyloid. Pileus context beneath the pellicle consisting of floccose interwoven hyphae with hyaline thin walls more or
less incrusted with dingy to pale bister granules or particles, nonamyloid.
Pileus cuticle a thick gelatinous layer of interwoven nonamyloid appressed and incrusted hyphae 4-8 u in diameter. Stipe surface a layer of
gelatinous hyphae similar to those of the pileus cuticle, no caulocystidia
found. Clamp connections absent.
Chemical reactions: KOH on surface of the pileus deep red, on
context pink. NH40H on surface of the pileus deeper and richer red
than with KOH. FeSO4 on surface of slime blue. Melzer's reagent on
flesh red without a peripheral green zone.
Habit, habitat, and distribution.-Gregarious under conifers, usually
hemlock or arborvitae in Michigan. It is rare in the state but is known