678 



Barberry- 

 Sedges (Car ex) 

 Goosefoot 



WEED FLORA OF IOWA 



[ Rust of wheat (Puccima grammis Pers.) 



} Gooseberry-leaf Cluster -cup (Puccinia 

 pringsheimiana Kleb. ) 



I Peronospora effusa Rab., on spinach. 



Docks, Sorrel, and many"! Rosellinia radiciperda Mass. A white 

 others J Root-rot in New Zealand. 



1 Chrysanthemum Rust (Puccinia hieracii 

 Hawkweed (Hieraciwm) > Mart.) 



Groundsel, Ragwort, and"! Pine Cluster-cups (Peridermium pini 

 other species of Seneclo j Wallr.) 



Many wild grasses 



\ Ergot of rye (Claviceps purpurea Tul.) 



Pio. B25. Leaf rust of Wild Barley (Puccinia rubigo-vera) also occurs on 



wheat. 

 (Drawing by Charlotte M. King.) 



These fungus diseases are particularly noticeable in a number 

 of plants of the mustard family. The Cystopus cnndidus common 

 upon cabbages in Europe is very common on a large number of 

 cruciferous plants, like mu.«tard, peppergrass. charlock, etc. At 

 times it is very common upon the radish. A related fungus, downy 

 mildew, of the mustard {Peronospora parasitica) is common and 

 troublesome at times on some cultivated members of the mustard 

 family. It is particularly common upon peppergrass and shep- 



