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

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THE BOLETES OF MICHIGAN

11. Suillus subaureus (Peck) Snell in Slipp & Snell
Lloydia 7:30. 1944
Boletus subaureus Peck, Ann. Rept. N. Y. State Mus. 39:42. 1886.
Rostkovites subaureus (Peck) Murrill, Mycologia 1:13. 1909.
Ixocomus subaureus (Peck) Singer, Rev. de Mycol. 3:45. 1938.
Illus. P1. 15.
Pileus 3-12 (17) cm broad, convex with an incurved margin, expanding to broadly convex to nearly plane, often with a fluted or flared
margin, margin often remaining inrolled for a long time, slightly downy
but no veil or false veil is present on buttons; surface viscid beneath a
covering of appressed tomentum which may be brownish at first but on
many pilei becomes aggregated into patches or fibrillose scales which
become scarlet to cinnabar-red and spotlike in appearance, surface rarely
appearing glabrous with age, ground color yellow to apricot-yellow. Context up to 3 cm thick, yellow, unchanging or staining brownish to
vinaceous-brown; taste mild to slightly acid, odor not distinctive.
Tubes subdecurrent when young becoming decurrent in age, (3)
4-10 mm deep, somewhat radially arranged, ochraceous to luteous becoming flavous, unchanging when bruised, somewhat separable from
pileus context; pores about 2 per mm, angular and arranged so as to be
inconspicuously lamellate, dingy yellow becoming dull ochraceous.
Stipe 4-8 cm long, 1-2 cm thick, equal to tapering downward to
occasionally subclavate, solid, flavous within, then reddish tawny where
cut, with a ferruginous to fulvous zone in the base as seen in a longitudinal section, yellow overall, glandular dots showing up in age when
they have discolored, viscid at least when young, surface sordid brownish from handling, basal mycelium whitish.
Spore deposit olive-brown ("light brownish olive") fresh; spores
7-10 X 2.7-3.5,, narrowly elliptic to subfusiform in face view, in profile obscurely inequilateral, smooth, pale greenish yellow in KOH to
nearly hyaline, scarcely darker in Melzer's.
Basidia 4-spored, 23-88 X 5-7 j, clavate, hyaline to yellowish in
KOH, yellowish in Melzer's. Pleurocystidia (25) 40-50 X 4-6 J, clavate
to cylindric, mostly in bunches and more or less covered with dark
yellow-brown amorphous pigment as revived in KOH, in mounts of fresh
material (in KOH) purple to lilac or rarely some of them hyaline, or
with bister content, thin-walled. Cheilocystidia similar to pleurocystidia,
very abundant, often crooked near the apex, the surrounding amorphous
pigment very abundant. Caulocystidia abundant and scattered over the
surface, 50-70 (100) X 3-5 uL, filamentous to cylindric (often flexuous),