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

44 THE BOLETES OF MICHIGAN
5. Pileus glabrous or with a slight patchy appearance along margin; pores
2-3 per mm................. S. albidipes
5. Pileus spotted with brown patches of veil remnants; pores 1-2 mm broad
at maturity (if tube mouths are smaller and pileus has red spots or streaks
or grayish patches of appressed tomentum see S. subaureus and S.
hirtellus)................... S. sibiricus
6. Stipe base conspicuously staining yellow when injured.... S. lutescens
6. Not staining as in above choice................ 7
7. Stipe 1-2.5 cm thick; annulus with a thin vinaceous-gray to purple-drab
layer or zone on its outer side which may gelatinize in wet weather... S. luteus
7. N ot as above...................................... 8
8. Veil soft and baggy, flaring outward at lower edge before breaking
(see P1. 21)........................... S. subluteus
8. Veil not as above-much less conspicuous.................. 9
9. Pileus white at first, taste of slime on pileus very acid......... S. acidus
9. Pileus distinctly colored when young....................... 9a
9a. Pileus ocher-yellow or darker; taste of slime on pileus very
acid......................... S. intermedius
9a. Pileus pallid to dingy cinnamon; slime on pileus mild... S. subalutaceus
10. Pileus white at first; stipe having conspicuous pinkish brown smears.. S. placidus
10. Pileus more highly colored..............................11
11. Pileus soon glabrous and deep dull yellow; odor sweetly fragrant
(in large collections)....................... S. punctipes
11. Not as above................................... 12
12. Pileus white in button states but becoming cinnamon to reddish cinnamon, glabrous but finally obscurely spotted from drying gluten..S. granulatus
12. Pileus glabrous or decorated with patches of fibrils but not as above......13
13. Tubes boletinoid at maturity; pileus glabrous and pinkish brown
to dull cinnamon or grayish brown; stipe conspicuously glandular
dotted.S................. punctatipes
13. Not as above...................................14
14. Pileus when young distinctly spotted with patches or tufts of fibrils or
tom entum........................................15
14. Pileus glabrous and slimy when young............16
15. Stipe with a ferruginous zone in the base when sectioned.......................................... S. subaureus
15. Stipe with an olive-fuscous zone in the base when freshly sectioned..................................... S. hirtellus
16. Basidiocarp lemon-yellow overall...................S. unicolor
16. Not as above.........................17
17. Pore surface with copious droplets of latex when young.... S. lactifluus
17. Pore surface not showing droplets of latex at first or any other
time......................... S. brevipes