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

SUILL US

47

fresh; margin when young with cottony material along it like the tufts
of fibrils on the pileus. Context pale yellow, not staining blue when
bruised, odor and taste mild.
Tubes shallow, 3-8 mm deep, decurrent and with lines extending
down the stipe a short distance, pale yellow to ochraceous; pores at
maturity compound and elongated, about 1 mm wide, pale yellow when
young, more orange-buff in age, staining slightly vinaceous-brown where
bruised.
Stipe 3-8 cm long, 1-2 cm thick at apex, equal or enlarged downward, solid, yellowish within above but soon olive-fuscous in the base;
surface glandular dotted, pale yellow overall including the dots and these
blackening in age or from handling, base typically tapered to a point;
veil absent (tomentum of pileus never connected to the stipe).
Spore deposit "Sayal-brown" (dull cinnamon); spores 7-9 X
3-3.5 g, smooth, nearly oblong in face view, in profile somewhat inequilateral, apical and slightly turned up in many (as seen in profile),
pale ochraceous in KOH, pale tawny in Melzer's reagent.
Basidia 4-spored, 17-23 X 4-5.5 /a, narrowly clavate, pale ochraceous
in KOH. Pleurocystidia in prominent clusters, incrusted with brown
amorphous material, individual cystidia (30) 40-70 (80) X 6-9 Iu, clavate
to subcylindric, hyaline to brown in KOH, often with refractive reticulate content. Cheilocystidia similar to pleurocystidia, much amorphous
pigment present. Caulocystidia similar to pleurocystidia, much amorphous pigment present, occurring in clusters. Caulohymenium often
showing sporulating basidia; subhymenium gelatinous.
Tube trama of gelatinous, divergent, hyaline hyphae as revived in
KOH. Epicutis of pileus a pellicle of loosely interwoven yellowish to
hyaline gelatinous hyphae 3-6 p in diameter. Clamp connections absent.
Habit, habitat, and distribution.-Gregarious under pine and aspen
throughout the aspen areas of the state, common in the summer and fall
during wet weather.
Observations.-The stipe may not appear glandular dotted at first
because the glandulae are the same color as the rest of the surface, but
they quickly darken from handling. The species is distinguished with
difficulty from S. subaureus, though the latter has less pileus ornamentation and the flecks it does have are more likely to become red by
maturity. Material cited is not included for this species because of the
difficulty in distinguishing the species on the basis of dried material, and
because there has been much confusion previously in regard to it.