374 



THE FUNGI WHICH CAUSE PLANT DISEASl. 



give rise to the pycnial and aecial stages. Considerable distor- 

 tion arises in parts affected by either stage. 



U. fallens (Desm.) Kem.^-^ A form on crimson, zig-zag and 

 red clover often confused with the last species. 



and I unknown. 



II. Urediniospores with four to six scattered germ pores. 



III. Teliospores similar to those of U. trifolii. 

 U. medicaginis Pass. 



and I. Pycnia and aecia as in U. pisi. 



II. Uredinia chestnut-brown, spores globose to elliptic, 17- 

 23 M, light-brown. 



Fig. 271.— Uredo stage of U. betae. After Scribner. 



III. Telia dark-brown, spores ovate-elliptic or pyriform 18-28 x 

 14-20. 



A hetercecious eu-type. I, on Euphorbia; in Europe. 



II and III on alfalfa and clovers in Europe and America. 



U. minor Schr. is an autoecious opsis-type, I and III on Trifo- 

 liirni montanum. 



U. betae (Pers.) Tul. ' An autoecious eu-type; on members 

 of the genus Beta both wild and cultivated. In the United States 

 observed only in California. Recorded in Europe, Africa, Australia. 



U. kuhnei Krug. occurs on sugar cane.^^^ 



U. dactylidis Otth. is a hetercecious eu-type; II and III on 

 Phleum, I on Rammculus, in Europe. 



U. pose Rab. is a hetercecious eu-type; I on Ranunculus and 

 Ficaria; II and III on Poa. 



