Hedgcock-Long : Notes on Three Rots of Juniper 113 



In the earlier stages of the rot, the wood is Hght brown and 

 under the hand lens is seen to consist of small pockets of rotting 

 tissue in the spring wood, thoroughly permeated with the fulvous 

 mycelium of the fungus ; at this stage the rot somewhat resembles 

 that produced by Polystictus abietiniis. As the rot advances, 

 these pockets coalesce longitudinally, thus destroying more or less 

 completely the spring wood. 



This rot, from the material at hand, does not seem to produce 

 holes in the tree but leaves the wood in the alternate-layered con- 

 dition above described. Later, certain fungi, especially species 

 of Poria, may attack and completely destroy the diseased wood, 

 thereby leaving the tree in a more or less hollow condition. This 

 fungus usually attacks only the heart wood, but also extends into 

 the sap wood, a condition which always arises wherever a sporo- 

 phore is formed. The entire heart wood for many inches may 

 be attacked and take on the characteristic reddish-brown layered 

 appearance previously noted. 



A micro-chemical examination of the diseased wood shows no 

 delignification, but the enzym seems to attack first the resinous 

 or gum-like contents of the medullary rays, then their walls and 

 thence passes to the tracheids, where small areas in the spring 

 wood are destroyed. The middle lamellae are not attacked by the 

 enzym, but the walls of the tracheids seem to be uniformly cor- 

 roded, the relative proportion of lignin, cellulose, etc., in their 

 walls changing not at all. This description was made from 

 material collected at Austin, Texas (type locality), on Juniperus 

 sahinoides, but the characteristics of the rot are the same on all 

 the hosts examined. 



Pileus woody, more or less ungulate to sub-cylindrical in very 

 old specimens, broadly attached, plane to slightly convex below ; 

 length 3-13 cm., breadth 4-1 1 cm., thickness 2-6 cm.; surface, 

 when young, tomentose, melleous, smooth, becoming sulcate by the 

 yearly accretions, older portion reddish-brown to black, glabrate, 

 strongly rimose ; margin very obtuse, rounded, melleous, tomen- 

 tose, smooth ; context woody, melleous to dark luteous, zonate, 

 1.5-2.5 cm. thick; tubes evenly but faintly stratified, 3 to 5 mm. 

 long each season, concolorous without luster, mouths circular, 

 4-5 to a millimeter, edges obtuse, entire, melleous to fulvous ; 

 spores rarely found, globose, smooth, 3-4 /x, cystida none, hyphae 

 brown, 5-7 /x in diameter. 



Type locality : Austin, Texas, on Juniperus sahinoides. 



Habitat : Trunks of living trees of /. sahinoides, J. mono- 

 sperma, and /. utahensis. 



Distribution: Southwest Texas, New A/[exico, and Arizona. 

 Very common in Texas and New Mexico. 



