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

SUILL US

39

6. Suillus pictus (Peck) Smith & Thiers
Contrib. toward a Monograph of N. Amer. Sp. of Suillus p. 31. 1964
Boletus pictus Peck, Ann. Rept. N. Y. State Cab. 23:128. 1872.
Boletinus pictus (Peck) Peck, Bull. N. Y. State Mus. 8:77. 1889.
Illus. Figs. 24-26; PI. 10.
Pileus 3-12 cm broad, broadly conic to convex or hemispheric, the
margin incurved, expanding to broadly conic-umbonate with a spreading
or decurved margin, or nearly plane, occasionally shallowly depressed,
margin typically appendiculate with veil fragments; surface dry, never
truly viscid but at times tacky when wet (especially when young),
coarsely fibrillose; cuticle at first red ("ocher-red"), fading on standing
in situ and in extreme age, the fibrils often grayish, or tips of the
squamules fuscous. Context up to 1.5 cm thick, yellow, changing to
pinkish gray to reddish ("avellaneous" to "russet-vinaceous") upon exposure, floccose. Taste and odor mild.
Tubes not readily separable, adnate to decurrent, often extending
down the stipe, about 5 mm deep, bright yellow; pores concolorous
with sides, large at maturity (0.5-2 X up to 5 mm radially), smaller
toward the pileus margin, angular, often compound, changing to reddish
or brownish ("avellaneous") when injured.
Stipe 4-10 (12) cm long, 8-25 mm thick, equal or enlarged downward, occasionally with a clavate to subclavate base, solid, rarely hollow;
context white in the interior or brownish at the base, cortex yellowish
or occasionally concolorous with exterior, lower portion sheathed with
remains of a fibrillose coating similar to the fibrils of the pileus and
breaking into zones or patches, often terminating in a fibrillose annulus,
with a whitish, delicate, more or less cortinate partial veil in addition,
apex yellow and more or less reticulate from decurrent lines from the
tubes.
Spore deposit clay color to tawny-olive as air-dried, olive-brown
before moisture has escaped; spores 8-11 (12) X 3.5-5 JI, smooth, apical
pore lacking, narrowly ovate in face view, narrowly inequilateral in profile view, olive yellowish in KOH mounts as revived, yellow to pale
tawny in Melzer's.
Basidia 4-spored, 20-26 X 6-8 p, hyaline in KOH, yellow in
Melzer's. Pleurocystidia abundant, clavate, 30-40 X 9-12/u, with cinnamon-colored content in KOH, much more numerous than the above
are large prominently projecting cystidia 55-75 X 7-10,, subcylindric,
flexuous, or straight and with a subacute to obtuse apex, hyaline and
thin-walled but usually with bister incrusting material where surrounded