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

FUSCOBOLETINUS

79

31. Fuscoboletinus sinuspaulianus Pomerleau & Smith
Brittonia 14:165. 1962
Suillus sinuspaulianus (Pomerleau & Smith) Singer, Snell, & Dick, Mycologia
57:457. 1965.
Pileus 3-13 cm broad, at first subconic, then convex to broadly
convex, becoming plane and sometimes subumbonate; surface smooth or
somewhat wrinkled, obscurely innately fibrillose, glabrous, glutinous,
deep ferruginous to chestnut-brown, sometimes fading to dull orangebrown, the separable veil appearing as patchlike scales from the drying
gluten; margin at first incurved and appendiculate with veil remnants,
and with a narrow sterile band. Context very soft and watery, dingy
orange-buff to yellow; odor somewhat mealy; taste not distinctive.
Tubes broadly adnate to decurrent, separable from the context of
the pileus, up to 1 cm thick near the stipe in large basidiocarps, becoming very soft and readily collapsing, dull yellow-brown ("buckthorn-brown"), almost "snuff-brown" in age, darkening when bruised;
pores concolorous, angular, 1-2.5 mm broad, typically boletinoid and
compound, with radiating lines, fimbriate when young, becoming
densely spotted on the side with fine reddish or deep brown dots when
old and dry.
Stipe 4-12 cm long, 1-3 cm thick, subequal and enlarged in the
middle or below, central but sometimes a little eccentric, not glandular
dotted anywhere, reticulate and dull yellowish brown above the annulus,
fibrillose, floccose or squamulose, grayish brown to grayish red, lined or
spotted with red below the annulus, solid, golden-yellow and watery
within, reddish around wormholes and becoming slowly reddish toward
the base when exposed.
Spore deposit deep purple-brown or dark chocolate-brown in mass
when old; spores 8-10.5 (13.2) X4-4.5 (4.8) I, smooth, lacking an apical
pore, in face view elliptical or narrowly ovate, inequilateral in profile,
slightly depressed above the inconspicuous hilar appendage, mostly narrowed at the apex, greenish hyaline to pale fuscous in KOH, yellowish
to dark tawny or in part dextrinoid, with slightly thickened wall.
Basidia 20-24 X 3.5-5,u, 'hyaline in KOH, narrowly clavate,
4-spored. Pleurocystidia scattered or in clusters, 25-50 A broad, subcylindric to very slightly fusoid-ventricose, 40-60 X 4-6 j individually,
often projecting 30-45 p beyond the hymenium, with obtuse to
subacute apices, typically thin-walled, hyaline to dingy brown either
from coagulated content or brown incrustations in the basal area of only
the clustered ones.