4 BULLETIN 496, U. S. DEPARTMENT OF AGRICULTURE. 



inous fungus (Exidia glandulosa] found at irregular intervals along 

 the twigs and small branches. Its action on the wood is to produce 

 whitish rotten areas, usually extending entirely through the branch, 

 thus forming a line of weakness which ultimately causes the branch 

 to break into small sections (2 to several inches long). These pieces 

 fall to the ground, where complete disintegration follows. 



Merulius corium, Hymcnochaete curtisii, Diatrype stigma , and 

 Stereum kirsutum are other fungi occasionally found attacking the 

 twigs and small branches, while Merulius tremellosus, Polystictus 

 pergamenus, P. versicolor, Polyporus gilvus, P. cinnabarinus, P. 

 benzoinus, Lenzites betulina, Flammula sp., Panus stipticus, Stereum 

 spadiceurn, Lycoperdon pyriforme-, Xylaria hypoxylon, and several 

 species of Poria are occasionally found rotting logs, stumps, and 

 large branches. 



Panus stipticus, Flammula sp., Mei^ulius tremellosus, Xylarria 

 hypoxylon, and Lycoperdon pyriforme are fungi which apparently 

 attack wood w r hich has been more or less rotted by other fungi. 



Polystictus pergamenus, P. versicolor, Polyporus gilvus, P. cinna- 

 barinus, P. lenzoinus, and Lenzites betulina rot both the sapwood 

 and heartwood, but unfortunately none of them are common on oak 

 slash in the forests of Arkansas. None of the fungi found rotting 

 the oak slash produces a heart rot in the living tree. However, cer- 

 tain fungi which cause heart rots in living oak trees will continue to 

 grow in the infected w r ood after the trees are felled. The most impor- 

 tant of these are Ilydnum erinaceus, Polyporus pilotae, P. sulphu- 

 reus, and Stereum subpileatum. 



BRUSH WHEN PULLED. 



Soon after a living tree is felled, wood-boring insects and various 

 fungi begin their work of disintegration and decay. The first evi- 

 dence of fungous activity in slash is a discoloration of the sapwood 

 in the twigs, branches, and trunks, which usually begins a few 

 months after the trees are felled. Marked evidences of decay in the 

 shape of well-defined rotten spots and areas in the wood and the 

 formation of fruiting bodies or sporophores of the wood-rotting 

 fungi do not appear until one or two years after the trees are felled. 



All of the leaves in the tops of felled oak trees will usually fall in 

 from one to three years, depending more or less upon the age of the 

 leaves at the time the oak was cut and to a slight extent on the 

 locality in which the timber is situated. 



The small branches and twigs gradually rot, and the majority of 

 them will have fallen to the ground at the end of four years. By 

 the end of six years practically all of the branches in the tops will 

 have rotted and fallen except some of the very large ones which 

 have much heartwood. Also, practically all of the sapwood in the 

 boles and cull logs will have rotted away during this time. 



