464 DISEASES OF ECONOMIC PLANTS 



Pseudomonose, tumor, gall {Pseudomonas tumefaciens 

 Smith & Townsend). — Galls upon the stems of this 

 plant have been proved by Smith and Townsend' to be 

 due to a species of Pseudomonas. Treatment has not yet 

 been discussed. 



CLEMATIS 



Phomose {Phoma sp.). — Plants affected with this disease 

 were first noted in 1883.^ They showed roots which were 

 rotted for several centimeters distant from the stem. 

 Minute black pycnidia occurred upon the affected parts. 



COREOPSIS 

 Rhizoctonia. See p. 61. 



COSMOS 



Phlyctaenose (Phlyctcma sp.). — The first indication of 

 disease is seen in brown discoloration of the stem or 

 branches, the attack often, though not always, occurring 

 at a wound. The diseased branches at the point of at- 

 tack are weak and frequently break off. Minute pycnidia 

 are present in the diseased parts. 



CYCLAMEN 



Phomose {Phoma cyclamenoe Halst.). — A disease of the 

 foliage which sometimes causes almost entire loss of the 

 crop is marked by large, dark, irregularly shaped spots 

 upon the leaf. These spots later dry, turn lighter in 

 color, and show a series of concentric light and dark 



' Smith, E. F., and Townsend, C. O., Centbl. Bakt. 22, 89, December, 

 1907. 



' Arthur, J. C, N.Y. (Geneva) Agr. Exp. Sta. Rpt. 3, p. 383, 1884. 



