TROPICAL POLYPORES 19 



to a mm., edges thin, dentate, white to discolored, umbrinous or 

 fuliginous in herbarium specimens; spores obovoid, smooth, 

 hyaline tinged with cream-olive, 15-18 X 8-12 p. 



Found on stumps of Cedrela odorata once in Costa Rica and 

 once in Yucatan. 



6. TYROMYCES P. Karst. 



Hymenophore annual, epixylous, sessile, anoderm, azonate, 

 glabrous or nearly so; context white, fibrous, fleshy to fleshy- 

 tough, rigid and friable when dry; tubes thin-walled, white or 

 yellowish, mouths polygonal; spores smooth, hyaline. 



Pileus large, 8 cm. or more in diameter. 

 Tubes less than 5 mm. long. 

 Pileus over i cm. thick. 

 Pileus 3-5 mm. thick. 

 Tubes more than 5 mm. long. 

 Surface of pileus very smooth. 



Pileus white or slightly yellowish, unchanging; 



tubes small, entire. 

 Pileus becoming dark-sordid-bay throughout 



on drying; tubes 3 to a mm., lacerate. 

 Surface of pileus not very smooth; tubes minute; 



spores subglobose, 3 M- 



Pileus small, rarely exceeding 5 cm. in diameter. 

 Pileus resinous or cartilaginous in appearance. 

 Pileus neither resinous nor cartilaginous in appear- 

 ance. 



Hymenium more or less bluish or bluish-spotted. 

 Pileus effused-reflexed, white or pale-isabel- 



line. 



Pileus not effused-reflexed, more or less bluish. 

 Hymenium not tinged with blue. 



Pileus white or nearly so, sometimes becoming 



slightly darker with age. 

 Surface entirely glabrous throughout. 

 Pileus effused-reflexed, 1.5 cm. broad. 

 Pileus flabelliform, narrowly attached, 



2.5 cm. broad. 



Surface tomentose or pubescent, some- 

 times becoming nearly glabrous. 

 Tubes 4-5 to a mm.; species confined 



to high elevations. 

 Tubes 6-7 to a mm. ; species confined to 



low elevations. 

 Pileus gilvous or some shade of fulvous. 



Tubes 3-4 mm. long, much longer than the 

 thickness of the very thin context. 



1. T. palustris. 



2. T. Palmar um. 



3. T. nivosellus. 



4. T.Smallii. 



5. T. graminicola. 



6. T. versicutis. 



7. T. semipileatus. 



8. T. caesius. 



9. T. semisupiniformis. 



10. T. cinchonensis. 



ii. T. lacteus. 



12. T. leucomallus. 



13. T. albogilvus. 



