230 
THIRTEENTH REPORT. 
6. Pilens less than 12 cm. broad, with a short, central, thick, tomentose 
stem ; usually pileus is double, one beneath the other, rusty-yellow ; 
pores at first white-covered, then grayish-brown : 
Polyporus tomentosus Fr. 
(Coltrichia tomentosa). 
cf. Polyporus circinatus Fr. 
7. Fruit-body grown together in the form of numerous pilei : (8) 
7. Fruit-bodv single or sub-caespitose (12) 
8. Hymenophore yellow to greenish-yellow, decurrent; pilei becoming 
fragile, large, yellowish-green; stem 3-6 cm. long, thick: 
Polyporus poripes Fr. 
. Grifola poripes) . 
cf. Polyporus flavovirens B. & Rav. 
8. Hymenophore white; (tinged yellow in the first species follow- 
ing) : (9) 
9. On decayed trunks of apple trees; pilei tufted, each 10-15 cm. broad, 
white or tinged yellow; common stem short and very thick : 
Polyporus admiral) ilis PK. 
9. On Larix and Cedar; pilei tough then hard, almost horny, even and 
glabrous; stems short, connate: Polyporus osseus Fr. 
9. On the ground, or at base or around oak trees: (10) 
10. Surface of pileus gray or grayish-brown to coffee-colored; pilei very 
numerous and small, 1-6 cm. broad each: (11) 
10. Surface of pileus whitish to pale tan ; pilei large, 5-15 cm. or more 
broad. Flesh milky in young plants; tubes large, 1 mm. diam. 
Polyporus Berkeleyi Fr. 
Grifola Berkeleyi). 
11. Pilei lateral, spatulate or dimidiate: Polyporus frondosus Fr. 
(Grifola frondosa). 
11. Pilei central, umbilicate and circular: Polyporus umbellatus Fr. 
(Grifola ramosissima) . 
12. Plants rather fleshy; growing on the ground (13) 
12. Plants tough; on wood: (15) 
13. Stem black and rooting; pileus subtomentose, smoky -brown : 
Polyporus radicatus Selim. 
(Scutiger radicatus). 
13. Stem not black, nor rooting: (14) 
14. Pileus blue when fresh; tubes blue when young: 
Polyporus holocyaneus Aik. and Polyporus caeruleporus PK. 
(Scutiger) . 
14. Pileus ashy-gray; tubes white-stuffed when young: 
Polyporus griseus PK. 
(Scutiger griseus). 
