PINE DISEASES 283 



its alternate stages on sweet-fern and sweet-gale instead of on 

 currants and gooseberries (see page 279). 



References 



Spaulding, P. Notes on Cronartium Comptonise, II. Phytopathol- 

 ogy 3 : 308-310. 1913. 



CUnton, G. P. Cronartium Comptonise Arth. (I. Peridermiumpyri- 

 forme Pk.). Connecticut Agr. Exp. Sta. Ann. Rept. 1907- 

 1908:380-383, pi. 28. 1908. 



Weir, J. R. Observations on the pathology of the jack pine. U. S. 

 Dept. Agr. Bui. 212 : 1-10, pi. 1, figs. 1-4. 1915. 



Spaulding, P. Notes on Cronartium Comptonise III. Phytopathology 

 7 : 49-51. 1917. 



CoMANDRA Rust , 



Caused by Cronartium comandrm Peek 



This is one of the six blister-rust diseases of the stems of 

 pines in the United States. Although known commonly as 

 blister-rust, it is here called the Comandra rust of pines to 

 distinguish it from the other five similar diseases. The Co- 

 mandra rust occurs on pines having two or two- to three needles 

 in a bundle and not on the three-needle pitch pines. It has 

 been found on lodge-pole, Jack, western yellow and table-moxm- 

 tain pine, in several eastern, north-central and western states. 

 A part of the life history of the causal fungus is spent on species 

 of Comandra and on these plants it has been found over the 

 entire northern and central part of the United States from the 

 Atlantic to the Pacific. In the western states the Comandra 

 rust is an important disease of the pines which are susceptible. 

 In certain regions a large percentage of the younger trees 

 has been found affected or killed. Older trees are rarely 

 attacked. In Pennsylvania the disease causes the death of 

 many yoimg table-mountain pines. 



Symftoms. 



The trunks and limbs of trees less than two or three inches 

 in diameter are attacked. Spindle-shaped swellings are pro- 



