MICHIGAN ACADEMY OF SCIENCE. 
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15 Pileus stipitate, but stem usually aborted so as to be at times re- 
supinate; flesli of two layers: Polyporus distortus Fcliw. 
(Abortiporus distortus). 
15. Stem not aborted: (16) 
16. Stem black, either at base or thruout, often lateral or eccentric :( 17) 
16. Stem whitish to brownish; pileus rarely more than 2-5 cm. 
broad : (20) 
17. Pileus scaly, thickish, large, rather soft and putrescent; pores large, 
angular, shallow: Polyporus squamosus Fr. 
(Polyporus candicinus). 
17. Pileus even, glabrous, firm becoming hard: (18) 
18. Pileus large, 6-20 cm. broad (19) 
18. Pileus smaller, pale leather-colored; stem central, abruptly black 
below : Polyporus clegans Fr. 
19. Surface of pileus milk-white, center darker, tubes milk-white; stem 
smoky below ; on roots from the ground : 
Polyporus Underwoodii Murr. 
19. Surface of pileus chestnut colored to yellowish or blackish ; stem 
entirely black: Polyporus picipes Fr. 
20. Pileus zonate, mostly on the ground or on humus in woods:. . . . (21) 
20. Pileus not zonate: (22) 
21. Pileus with lacerate margin, shining cinnamon : 
Polyporus cinnamomeus 8. F. Gray. 
see : Polystictus cinnamomeus. 
(Coltrichia cinnamomeus) . 
21. Pileus with fimbriate or entire margin, rusty-brown : 
Polyporus pcrennis Fr. 
see: Polystictus perennis. 
(Coltrichia perennis). 
22. Margin of the pileus strigose-hairy ; mouths of tubes large, rhom- 
boid: Polyporus arcularius Fr. 
22. Margin of pileus not strigose: (23) 
23. Surface of pileus fibrillose or villose-tomentose : (24) 
23. Surface of pileus glabrous: (25) 
24. Pileus drab-colored, tufted with fibrils, tubes milk-white, angular, 
decurrent: Polyporus fagicola Murr. 
24. Pileus smoky to yellowish-brown, hispid-scaly; tubes whitish, round. 
adnate:. Polyporus brum alls Fr. 
(Polyporus Polyporus) . 
25. Flesh yellow; surface of pileus bay-brown; tubes decurrent, mouths 
minute: Polyporus pliaeoxanthus B Sc M. 
25. Flesh white: (26) 
