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

The BOLETACEAE Chevalier
Flore Env. Paris p. 248. 1926 (as "ordre")
We recognize only 1 family for pore fungi with fleshy readily
decaying basidiocarps typically centrally stipitate, and with the hymenophoral trama as seen in a longitudinal section having hyphae more or
less in bilateral arrangement. We place the family in the Agaricales. We
place Phylloporus in the Paxillaceae, following Watling (in press).
Type genus: Boletus Fries.
KEY TO GENERA
1. Spore deposit not obtainable-the tubes usually oriented in such a way
that the spores cannot fall free of them; spores not discharged from
the basidia in the normal manner.......................... Gastroboletus
1. Spore deposit readily obtained from basidiocarps in good condition and
near m aturity................................................... 2
2. Pileus covered with coarse dry gray to blackish scales; spores
globose to subglobose and their surface reticulate to verrucose;
spore deposit blackish brown or nearly so................ Strobilomyces
2. Pileus not as above; spores smooth or if elongated then either
smooth or ornamented........................................ 3
3. Spores ornamented by longitudinal wings, folds, or striations........ Boletellus
3. Spores smooth or the ornamentation different than in above choice.......... 4
4. With any 2 or more of the following features in combination:
(a) hymenophore boletinoid at maturity; (b) stipe glandular dotted;
(c) veil leaving an annulus on stipe; (d) pileus glutinous to viscid;
(e) pleurocystidia in bundles and as revived in KOH with incrusting
brown pigment around or on the bundle........................... 5
4. Not with above combinations of features........................... 6
5. Spore deposit grayish brown to wood-brown, vinaceous-brown, purplish
brown, chocolate-brown to purple-drab.................... JFuscoboletinus
5. Spore deposit dingy yellow to yellow-brown, pale cinnamon-tan, olive,
olive-brown, or a greenish mustard-yellow.......................... Suillus
6. Spore deposit pale yellow; spores more or less ellipsoid; stipe hollow
at maturity........................................... Gyroporus
6. Not as above................................................. 7
7. Veil dry and flocculent to almost powdery (in appearance) and typically
leaving a zone or ring on the stipe when it breaks............. Pulveroboletus
7. Veil lacking or not as above if present................................. 8

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