DISEASES OF TAXODIUM AND LIBOCEDRU8. 



THE " PIN " DISEASE OF LIBOCEDRUS DECURRENS. 

 HISTORICAL. 



In 1879 Harkness * published a note in which he called 

 attention to a peculiar rot which occurs in the heart 

 wood of the incense cedar, Libocedrus decurrens. Mayr f 

 mentions what is evidently the same disease and describes 

 it as follows : " A certain fungus, Daedalea vorax 9 appears 

 to be very destructive, destroying the heart wood of stand- 

 ing trees ; the fungus colors the wood red-brown and forms 

 large lens-shaped cavities, at the same time the wood 

 becomes very " briichig." In 1896 the following appeared 

 in Sargent's Silva: J " The trunks of Libocedrus decurreiis 

 are frequently honey-combed and its value destroyed as a 

 timber tree by Daedalea vorax, which destroys rounded 

 masses of wood, disposed in long rows, sometimes extend- 

 ing through the length of the trunk, reducing them to a 

 cinder-like powder." In the note published by Harkness 

 one is led to believe that Daedalea vorax attacks Abies 

 Douglasii, not Libocedrus. Daedalea vorax is reported 

 as growing on Libocedrus decurrens by Harkness. In a 

 letter received from Dr. Harkness last year he says: 

 * ' Daedalea vorax is a fungus which causes the rot in Abies 

 Douglasii^ etc. As to the Libocedrus disease he says : 

 " Nothing could be found except mycelium which per- 

 meates through the diseased portion. No visible signs of 

 any spores were seen. A careful search fails to reveal 

 any of the fungus either among the roots or the surface of 

 the tree, nothing indeed to indicate its presence until the 

 tree has been felled." He says furthermore that the note 



* Harkness, H. W. A foe to the lumberman. (Pacific Rural Press. 

 Jan. 25, 1879.) 



t Mayr, Heinrich. Die Waldungen von Nordamerika 324. Miinchen. 

 1890. 



I Sargent, C. S. Silva of North America 10 : 134. 1896. 



Harkness & Moore. Cat. of Pacific Coast fungi 12. (Read before the 

 Cal. Acad. of Sciences, Feb. 2, 1880). 



45 



