4 BULLETIN 490, U. S. DEPARTMENT OF AGRICULTURE. 



writer, however, does not wish to call it by this name until the in- 

 vestigations now under way as to its identity are completed. 



Lloyd reports a specimen of the same fungus from the State of 

 Washington, collected by J. M. Grant, 1 and refers it to Polyporus 

 ellisianus. The writer (through the kindness of Mr. Lloyd) has been 

 able to examine a portion of the collection from Washington, and it 

 agrees in all essential characters with the fungus which causes west- 

 ern red-rot in Arizona and New Mexico, Concerning the host of the 

 Washington specimen Lloyd writes, " There was no note with the 

 specimen regarding its host, excepting that it grew on a pine of some 

 kind." 



A sporophore of what is apparently the western red-rot fungus 

 has been examined from Idaho. 



Von Schrenk 2 in 1903 published a figure of a heart-rot of living 

 trees of Pinus ponderosa from the Black Hills Forest Reserve in South 

 Dakota, which is typical of the second stage (cross-sectional view) 

 of this rot as it occurs in yellow pine in New Mexico and Arizona. 

 It is therefore highly probable that this fungus is widely distributed 

 throughout the West, both as a saprophyte in slash and dead trees 

 and as a heart-rot in living timber. The writer has examined a speci- 

 men of the same fungus collected in New Jersey on Pinus sp. and one 

 of both fungus and rot from Vermont on P. strobus. 



ENTRANCE OF WESTERN RED-ROT INTO LIVING TREES. 



The western red-rot fungus enters the living tree through dead 

 branches in the crown. It first attacks the sapwood of the dead 

 branch ; then the heartwood. It then travels down the sapwood and 

 heartwood of the dead branch into the heartwood of the living tree. 

 Once established in the tree, the fungus apparently continues to grow 

 as long as the tree is alive, spreading in all directions, until often the 

 heartwood of the entire bole of the tree, as well as that of the large 

 branches, is invaded and rendered worthless for lumber. 



EXTERNAL SIGNS OF WESTERN RED-ROT. 



No external signs were found which would absolutely determine 

 whether or not a given standing yellow-pine tree was defective. 

 Trees having large dead branches intermixed with living limbs and 

 ragged and unhealthy looking crowns were often attacked by western 

 red-rot. Such defective trees were usually located on very thin soil on 

 steep south or east slopes, where growth conditions were very poor. 

 However, many trees which showed no recognizable external evi- 

 dences of decay were found to have western red-rot when they were 

 felled. 



1 Lloyd, C. G. Mycological writings, v. 4, letter no. 60, p. 4. 1915. 



- Schrenk, Hermann von. The " bluing " and the " red rot " of the western yellow pine, 

 with special reference to the Black Hills forest reserve. U. S. Dept. Agr., Bur. Plant 

 Indus. Bui. 36, p. 34, 40, pi. 14, fig. 2. 1903. 



