142 



Mycologia 



are attacked, such limbs usually being more pendant than normal 

 ones, being slightly thickened and clustered, resembling slightly 

 the limbs in the pendant witches brooms formed by the stimula- 

 tion of the mistletoe, Razoumofskya cryptopoda (Eng.) Coville. 

 The fungus apparently spreads through the cambium of twigs, 

 often entering the new growth each year. The effect of the 

 fungus on the growth of such twigs is in some instances to 

 slightly increase the number of twigs produced, and to increase 

 their diameter; but usually there is no swelling produced. In a 

 number of older trees, 75 to 150 years old, the apparent effect of 

 the fungus on the main limbs had been to cause cankered areas 

 to form, and to kill the entire tops, producing spike-topped trees. 

 Such trees finally die, probably from the effects of insects or fungi 

 which follow the weakening effects of the Peridermium. A large 

 number of trees have either been stunted or slowly killed by this 

 fungus in the Montezuma National Forest. Judging from the 

 age and condition of many of the affected trees, the fungus has 

 been present in this region for many years. 



On Pikes Peak, beneath the trees diseased with Peridermium 

 filamentosum only one rust was found which could be associated 

 with this fungus as a telial form. The leaves of Castilleja integra 

 A. Gray were found diseased with the uredinia of Cronartium 

 coleopsorides (Dietel & Holway) Arthur during the second week 

 in July, 191 1. In the forest near Mancos, Colo., a few sori with 

 the telia of the same fungus was found on the same species of 

 Castilleja near some western yellow pines diseased with Peri- 

 dermium filamentosum. 



Peridermium filamentosum^ or a closely related species was also 

 found by Dr. E. P. Meinecke and Mr. W. H. Long, in Lassen 

 National Forest, September 16, 191 1, on the limbs and twigs of 

 Pinus contorta Loud. In the immediate vicinity, Cronartium 

 coleosporoides was found on a species of Castilleja, furnishing 

 additional proof of the possible relation of the latter species of 

 fungus to Peridermium. Inoculations will be made to verify this 

 assumption of relationship between Peridermium filamentosum 

 and Cronartium coleosporoides the coming season. 



^ This specimen has since been identified by Mr. W. H. Long as 

 Peridermium stalactiforme Arth. and Kern. 



