A NEW POLYPORE ON INCENSE CEDAR 



George Grant Hedgcock 



During the past three years the writer has repeatedly searched 

 in CaHfornia and Oregon for the cause of the " peckiness " or 

 pin-rot" of the incense cedar, which does great injury to the 

 heartwood of this species, and often affects as high as lOO per 

 cent, of the trees in a given area. The fungus whose description 

 follows was found definitely associated in an apparently causal 

 relation to the disease. 



Dr. Hermann von Schrenk described this disease of the incense 

 cedar under the name "pin disease" (Mo. Bot. Gard. Rept. ii: 

 45-55, pi. 2, 4, 5, June 3, 1899), without giving the cause. He 

 later assigned the cause of the disease to Polyporus libocedrus 

 (Science N. S. 16: 138, 1902), but, in the absence of type speci- 

 mens and a description, there is no means of knowing whether 

 or not his specimen and those now described belong to the same 

 species. 



Polyporus amarus sp. nov. 



Pileus soft and spongy when young, becoming hard and chalky 

 when old, ungulate, often' spuriously stipitate from knot-holes, 

 frequently large, 5-11X10-20X6-12 cm.; surface pubescent 

 when young, rimose and chalky when old, at first buff, becoming 

 tan and often blotched with brown when older; margin obtuse, 

 frequently having an outer band of darker brown, often slightly 

 furrowed ; context creamy-yellow to tan-colored, usually darker 

 in outer layers when old, bitter to the taste and often resinous 

 near the base, somewhat like Fomes Laricis (Jacq.) Murr., 4-8 

 cm. thick; tubes not stratified, brown within, cyHndric, 0.5-3 cm. 

 in length, shorter next the margin, mouths circular or slightly 

 irregular, 1-3 to a mm., yellow or yellow-green during growth, 

 turning brown when bruised or old, becoming lacerate ; spores 

 hyaline or slightly tinged with brown, smooth, ovoid, 3-4 X 5-8 fi, 

 nucleated ; cystidia none. 



Type locality: East slope of Marble Mt., Klamath National 

 Forest, California. Specimens collected October 14, 1909; other 

 specimens collected near Dunsmuir, Calif., October 16, 1907. 



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