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

BOLETUS

367

Observations.-This is one of the more distinctive species in the B.
edulis complex. Although the pileus has vinaceous to ferruginous tones
fresh, young pilei become yellow in drying ("ocher-yellow"). This color
change, the wide spores, pores staining vinaceous when bruised, and the
short terminal cells of the trichoderm with their gelatinous halo are
outstanding.
199. Boletus insuetus Smith & Thiers, sp. nov.
Pileus 3-8 cm latus, convexus, siccus, glaber demum areolatus,
pallide fulvus demum ochraceo-tinctus. Contextus albidus, immutabilis;
tubuli lutei immutabiles; pori lutei tarde luteo-brunnei. Stipes 6-9 cm
longus, 10-16 mm crassus, pallidus, reticulatus, demum luteo-maculatus.
Sporae 12-15 X 3.84.5 g. Specimen typicum in Herb. Univ. Mich. conservatum est; prope Colonial Point, Burt Lake, August 8, 1951, legit
Smith 37528.
Pileus 3-8 cm broad, convex becoming broadly convex; surface
dry, glabrous at first but soon more or less areolate-rimose; color pale
tan to pale tawny but developing yellow tones especially in aging
("cinnamon-buff' to "ochraceous-tawny"). Context white, unchanging,
taste mild, odor none.
Tubes depressed around the stipe, about 10 mm long, yellow,
unchanging; pores about 2 per mm and round, yellow, unchanging or
slowly yellowish brown.
Stipe 6-9 cm long, 10-16 mm at apex, clavate becoming equal,
pallid within but tending to yellow; surface whitish at base, but with
yellow stains, grayish brown over midportion and apex pallid to avellaneous, reticulate over upper half with a fine pallid network.
Spore deposit olive-brown; spores 12-15 X 3.8-4.5 u, narrowly
suboblong in face view to subfusoid, narrowly and obscurely inequilateral in profile, smooth, suprahilar depression broad and usually quite
distinct, walls only slightly thickened, dingy ochraceous revived in KOH,
many dark reddish brown in Melzer's, at least in part of the spore.
Basidia 4-spored, clavate, 23-30 X 7-9 p, yellowish in KOH to
hyaline. Pleurocystidia-none found. Pileus cutis a collapsed trichodermium of thin-walled smooth hyaline (in KOH) hyphae with reddish
content in Melzer's and 6-10 u broad, end-cells usually cystidioid from
being tapered to an obtuse apex. Clamp connections present but rare.
Habit, habitat, and distribution.-Scattered in a mixed forest,
Colonial Point, Burt Lake, August 8, 1951, Smith 37528.
Observations.-Peck described the spores of B. gertrudiae as 15-20
X 5-6 u. The stipe was described as yellow above and white below, the