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

SUILL US

35

Section PARAGYRODON (Singer) Smith & Thiers
Contrib. toward a Monograph of N. Amer. Sp. of Suillus p. 22. 1964
Paragyrodon Singer
Ann. Mycol. 40:25. 1942
The thick veil and subglobose spores are the distinguishing features
of this section. The color of the fresh spore deposit is rather peculiar,
but since it is a combination of olive and yellow this difference does not
seem to be sufficiently distinct to justify a monotypic genus-at least
not at the level at which we recognize genera in the boletes.
Type species: Suillus sphaerosporus.
4. Suillus sphaerosporus (Peck) Smith & Thiers
Contrib. toward a Monograph of N. Amer. Sp. of Suillus p. 22. 1964
Boletus sphaerosporus Peck, Bull. Torrey Club 12:33. 1885.
Paragyrodon sphaerosporus (Peck) Singer, Ann. Mycol. 40:25. 1942.
Illus. Pls. 5-7.
Pileus (4) 8-15 (20) cm broad, convex to plano-convex when
young, expanding to plane or shallowly depressed in age or at times the
margin uplifted and the shape becoming quite irregular; surface viscid to
slimy, glabrous, spotted or streaked with patches of dried gluten; when
young ocher to golden yellow ("ocher-yellow" to "buff-yellow" or
"old gold"), becoming ochraceous-tawny and finally dark dingy yellowbrown, often with rusty stains in age, readily staining brown when
bruised; margin incurved, entire, sterile. Context thick, up to 2 cm or
more, whitish to yellowish, changing to vinaceous-brown ("vinaceoustawny" to "testaceous") when exposed, odor and taste not distinctive or
occasionally unpleasant.
Tubes shallow in relation to thickness of pileus (4-10 mm deep),
adnate, becoming decurrent or with lines extending down the stipe,
canary-yellow ("mustard-yellow"), becoming golden yellow and finally
brown; pores large (about 1 mm diameter near maturity), angular, yellow
when young, staining brown ("cinnamon" to "tawny") when bruised.
Stipe 4-10 cm long, 1-3 cm thick, tapered to the base, or equal or
nearly so, solid, yellowish within but soon staining when cut or injured;
surface pruinose to glabrous above the heavy tough gelatinous more or
less median annulus, apex at times somewhat reticulate from decurrent
tubes which are pale yellow (pale "mustard-yellow") but which discolor