360 



TREDINEAE. 



This rust is indigenous to Chili, and was introduced into France 

 about 1868, whence it rapidly extended throughout the whole 

 of Europe, and during the last ten years has made its appear- 

 ance in the United States. In many places it has completely 

 exterminated both wild and cultivated mallows, and rendered 

 the cultivation of garden hollyhocks impossible. It appears in 



FIG. 192. 



in malvacearum. Mallow leaf, with teleutospore-sori. Three 

 teleutospores, one germinating, (v. Tubeuf del.) 



May or June on the leaves, stems, and petioles of the host ; 

 all are more or less deformed, and the leaves may in severe 

 cases wither up long before the flowers appear. Sponging 

 with a solution of permanganate of potash (two tablespoonfuls 

 in one quart of water), has been found an effective remedy. 



P. Sherardiana Korn. On mallow in America. 



P. heterogenea La^er. On hollyhock in South America. 



P. anemones-virginianae Sclnvein. On Anemone. (U.S. America.) 



