390 PLANT DISEASES 



tibrillose, hollow, yellow as is also its flesh; veil sometimes 

 appendiculate. 



Polyporaceae. — Sporophore with a central stem, dimi- 

 diate, or resupinate ; hymenium lining the cavities of long 

 or short, densely packed tubes, or shallow depressions ; 

 basidia tetrasporous. 



Polyporus, Mich.' — Stem central or lateral, or sessile and 

 dimidiate, etc. ; pileus fleshy, tough, rather soft and moist, 

 at length becoming harder (rarely of a cheesy texture and 

 fragile), externally neither sulcate nor zoned, but the 

 internal texture consisting of radiating fibres often more 

 or less zoned ; pores never stratose ; tubes not separable 

 from the sporophore, pores at first obsolete, then rounded, 

 angular, or torn. 



Polyporus schweinitzii, Fries, Sysf. Mjr., i. p. 351. — 

 Pileus 12-20 cm. across, tomentose, tomentum matted into 

 little rugged tufts, dark brown with a rusty tinge ; flesh 

 thick, spongy, fibrous, brown ; stem thick, very short, 

 brown, sometimes obsolete, more or less central when 

 present; tubes about i cm. long, pores large, irregular, 

 and variable in form, yellow, with a tinge of green ; spores 

 elliptical, obliquely apiculate, pale yellow, 7-8 X 4 /«. 



Polyporus squamosus. Fries, Sysf. Myc, i. p. 343. — 

 Broadly flabelliform, fleshy but thin, pliant, pale yellow 

 or whitish, with large adpressed, centrifugally arranged 

 brown scales, 12-25 cm. across, single or usually several 

 pilei springing from the same knob ; stem excentric or 

 lateral, short, base black ; tubes very short, becoming 

 large, angular, running down the under side of the stem, 

 whitish ; spores elliptical, colourless, 12X5 /^. 



Polyporus giganteus, Fries, Sysf. Myc, i. p. 356. — 



