WEED MIGRATION 



735 



of our plantains is of common occurrence. There is no morning- 

 glory. 



It may be of interest to compare the noxious weeds of Ger- 

 many with those of the United States. Dr. A. Thaer of the Uni- 

 versity of Giessen in 1881 published a small book on the agricul- 

 tural weeds of that country listing the following: (Those printed 

 in small capitals are also weedy in Iowa.) Corn poppy (Papaver 

 rhoeas), mustard (Brassica arvensis), charlock (Raphanus 

 raphanistrum), Canada thistle (Cirsium arvense), corn cockle 

 (Agrostemma githago), chickweed (Stellaria media), sheep sorrel 

 (Rumex acetosella), vetch (Vicia hirsuta), colt's-foot (Tussilago 

 farfara), corn chamomile (Anthemis arvensis), corn marigold 



Fig. 555. Cypress Spurge (.Euphorbia cyparissias) . Common in Europe and 

 waste places in Iowa. In many cases started in the vicinity of cemeteries. 

 (After Strasburger, Noll, Schenck and Karsten.) 



(Chrysanthemum segetum), groundsel (Senecio vernalis), corn- 

 flower (Centaurea cyanus), sow thistle (Sonchus oleraceus), 

 small bindweed (Convolvulus arvensis), clover dodder (Cuscuta 

 epithymum), broom rape (Orobanche ramosa), garden orach 



