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

BOLETUS

341

cutting, the red slowly fading to grayish, taste mild, odor fungoid, with
FeSO4 olivaceous, with KOH yellow, with Melzer's violet-gray.
Tubes up to 12 mm long, adnate becoming depressed, pallid at
first, becoming olivaceous and in age dull red ("Prussian-red") in places
throughout their length; pores 1-2 per mm, round to slightly angular,
dark dull red ("Prussian-red") in immature pilei, in age more reddish
brown, unchanging when bruised.
Stipe 5-11 cm long, 1-2 cm thick at apex, equal or nearly so,
solid, when cut olive-pallid in pith, cortex and lower half (especially the
base) dark rusty rose-red, not staining blue; surface "Prussian-red" lower
down and longitudinally ribbed to striate as well as with a fine dull red
reticulum, ground color dingy yellowish pallid becoming dull red like
the reticulum.
Spores (9) 11-14 X 5-7 u, smooth, with a thin spot at apex but
not a true pore, wall about 0.5 p thick in Melzer's and 1 u thick in
KOH, ovate to subelliptic in face view, subfusiform to obscurely kidney-shaped in profile (as in many spores of species in Inocybe dulcamera
group), cinnamon-brown individually in KOH, paler and near "snuffbrown" in Melzer's; some abnormal spores almost globose (fig. 110).
Basidia subelliptic in mature pilei, clavate when immature, 28-34
X 9-14., 4-spored, yellowish in KOH and Melzer's. Pleurocystidia 32-48
X 5-10 j, narrowly fusoid to fusoid-ventricose, smooth, thin-walled, in
old pilei some found which were 30-40 X 10-15 p and mucronate (giant
basidia?), all hyaline to yellowish in KOH or Melzer's. Cheilocystidia
similar to pleurocystidia but smaller (20-30 X 5-9 ju), content yellowish
brown in KOH.
Tube trama a central strand of more or less ochraceous-brown
hyphae (in young tubes) with color in both content and wall, with hyaline,
diverging hyphae extending to subhymenium, both types smooth. Pileus
cuticle a turf of narrow hyphae, tubular and with elongated end-cells
4-6 J wide, most of them seem to be surrounded by a mucilaginous
sheath (revived in KOH), the content of the cells of the trichodermium
amber-brown in Melzer's. Context hyphae near cuticle also with amberbrown content or hyaline. Clamp connections absent.
Habit, habitat, and distribution.-Gregarious by a trail in low hardwoods, Highlands Recreation Area, Oakland County, September 29,
1965, Smith 72730.
Observations.-The lack of any blue stains, the presence of deep
rusty red colors overall, deeply colored spores scarcely inequilateral in
profile view, and the reticulate stipe are distinctive. It is close to B.
rhodoxanthus and in fact was mistaken for that species in the field, but