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

EDIBILITY 409
b) Annulus if present gelatinous, at least on the edge.
c) Pores when mature obscurely to distinctly boletinoid (see
PI. 9).
d) Cap viscid to slimy when fresh.
e) Cap dry and squamulose and stipe sheathed with the veil......... 5
4. Not as above.................................... 6
5. Spore deposit as air-dried cinnamon, tan or yellow-brown, rarely olive. -. Suillus
5. Spore deposit (air-dried) lilac, purple-brown, vinaceous-brown, or grayish
brown with a pinkish tint....................... Fuscoboletinus
6. Spore deposit pale yellow; tubes white at first; stipe fragile and often
hollowed in the base........................... Gyroporus
6. Stipe solid and becoming toughish in age over lower part: spore
deposit olive-brown to rusty brown, vinaceous, vinaceous-brown,
chocolate (various shades) or fuscous-brown................... 7
7. Spore deposit reddish, cinnamon reddish, fuscous-vinaceous to chocolate
(various shades); tubes usually white to pallid when young...... Tylopilus
7. Spore deposit amber-brown, dingy yellow-brown, olive-brown, olive or
olive-fuscous........................... Boletus and Boletellus
(*) Gyroporus
As far as known, all the Michigan species are edible.
1. Context of cap instantly blue when injured............... G. cyanescens
1. Context not changing to blue or violet readily................... 2
2. Cap mineral-red to vinaceous-red........ G. purpurinus
2. Cap rusty to chestnut-brown or rich yellow-brown........ G. castaneus
Fuscoboletinus
1. Cap dry and fibrillose to squamulose, red.................F. paluster
1. Cap viscid at some stage (especially in age)..................... 2
2. Tubes white to pallid or grayish when young................. 3
2. Tubes yellow or soon becoming so....................... 6
3. Cap covered with a chocolate colored slime when young........ F. serotinus
3. Cap not as above......................... 4
4. Cap context pallid staining blue if injured...... F. aeruginascens (PI. 42)
4. Cap context as above but not staining blue, though tubes may stain
slightly..............................F. grisellus (P1. 43)
5. Cap with conspicuous dry floccose squamules over a viscid layer...F. spectabilis
5. Cap glabrous when young....................... F. glandulosus