DRY-ROT OF INCENSE CEDAR. 13 



appearance of a sporophore or fresh shot-hole cup, and one should 

 be influenced accordingly in judging the condition of a standing tree. 



THE DECAY. 



The dry-rot, described and pictured by Harkness (7), Von Schrenk 

 (26, p. 68, pi. 2), and Meinecke (15, p. 46, pi. 12), is a very characteris- 

 tic decay, most closely resembling the so-called peckiness of the 

 eastern cypress (Taxodium disticlium). Von Schrenk (26, p. 52-53) 

 points to this analogy, even suggesting that the two diseases may be 

 caused by the same fungus, but Long (12) has disproved this theory. 

 The former investigator (29, p. 30) also calls attention to the macro- 

 scopical similarity between this dry-rot and the brown-rot of redwood. 



Typically, the decay consists of vertically elongated pockets, 

 varying in length from one-half inch to about a foot, which are filled 

 with a brown friable mass, and the line of demarcation between the 

 sound and decayed wood is very sharp. In some of these pockets 

 small cobweblike or feltlike masses of white mycelium occur. The 

 pockets are separated from each other by what appears to be sound 

 wood, although in some cases streaks of straw-colored or brownish 

 wood may extend vertically between two pockets. This is especially 

 noticeable between young pockets. When immature the decay is 

 faintly yellowish brown, soft and somewhat moist, and not broken 

 up in the pockets. At times the mature pockets may be several feet 

 long and rather broad; this type always occurs in connection with 

 healed-over wounds, particularly healed fire scars in the butt of the 

 tree. The decay has never been found in living sapwood and is 

 usually confined to the heartwood of the trunk, but in very badly 

 decayed trees the dry-rot sometimes extends into the heartwood of 

 the larger limbs. 



In the aggregate, the immature decay or advance rot extends but 

 a short distance vertically in advance of the typical decay, and a dis- 

 tance of 2 feet beyond the last visible evidence of decay to the average 

 eye will usually exclude all immature decay. This immature decay 

 is very difficult to detect, occurring as it does in pockets, with the 

 color in the very earliest stages differing but slightly, if at all, from 

 the normal wood. 



An occasional pocket may occur several feet in advance of the main 

 body of decay, and while the wood of the pocket itself is of course 

 greatly weakened, the intervening wood is probably very little 

 affected, since the fungus hyphse are very sparingly found between 

 pockets of decay. In all, 566 trees containing typical dry-rot were 

 dissected. 



Typical dry-rot with small masses of white mycelium in some of 

 the pockets is shown in Plate III. 



