TROPICAL POLYPORES 89 



dead trunks of Guaiacum, Acacia, and certain other hardwood 

 trees, doubtless causing a serious heart-rot. 



41. PORODAEDALEA Murrill 



Hymenophore large, perennial, epixylous, sessile, conchate to 

 ungulate; surface anoderm, sulcate, usually rough; context brown 

 and woody; tubes concolorous, rarely in distinct layers, the 

 hymenium varying from porose to daedaleoid; spores smooth, 

 hyaline at maturity, becoming brownish with age; cystidia 

 conspicuous. 



i. PORODAEDALEA PINI (Thore) Murrill 



Pileus hard, typically ungulate, conchate or effused-reflexed 

 in varieties, often imbricate, 5-8 X 7-12 X 5-8 cm., smaller in 

 varieties; surface very rough, deeply sulcate, tomentose, tawny- 

 brown, becoming rimose and almost black with age; margin 

 rounded or acute, tomentose, ferruginous to tawny-cinnamon, 

 entire, sterile in large specimens; context soft-corky to indurate, 

 ferruginous, 5-10 mm. thick, thinner in small specimens; tubes 

 stratified, white to avellaneous within, becoming ferruginous at 

 maturity and in the older layers, 5 mm. long each season, much 

 shorter in thin specimens, mouths irregular, circular or daedale- 

 oid, often radially elongate, averaging I to a mm., edges fer- 

 ruginous to grayish-umbrinous, glistening when young, rather 

 thin, entire; spores subglobose, smooth, hyaline at maturity, 

 becoming brownish with age, 5-6 X 3-4 M; cystidia abundant, 

 short, 25-35 X 4-6 /z. 



This species attacks living trunks of conifers in temperate 

 regions, causing a very serious heart-rot. It may be expected 

 to occur in the pine forests of tropical America, especially at 

 high elevations. 



42. NIGROFOMES Murrill 



Hymenophore large, perennial, epixylous, sessile; context 

 woody, purple; tubes cylindric, stratose, thick- walled, black; 

 spores ovoid, smooth, hyaline. 



i. NIGROFOMES MELANOPORUS (Mont.) Murrill 



Pileus very hard, heavy, conchate to applanate, dimidiate, de- 

 current, 6-10 X 10-15 X 1-2 cm.; surface tomentose, nearly 

 smooth, fuliginous to black, becoming glabrous, shining, several 

 times sulcate and often rough and tuberculose with age ; margin 

 usually deflexed, at least when dry, sterile, rounded, rarely acute, 



