WEED MIGRATION 



727 



Fig. 550. Curled Dock (Rumex crispus). A common European weed now 



occurring across the continent. 



(After Chesnut, U. S. Dept. Agr.) 



found in the northwest. A few of the abundant species may be 

 mentioned. Russian thistle (Salsola kali var. tenuifolia) is abun- 

 dant in the drier regions, especially east of the Cascades. In the 

 Puget Sound country are found such common European weeds as 

 Canada thistle (Cirsium arvense) , bull thistle (C. lanceolatum) , 

 batchelor's button (Centaur ea cyanus), chicory (Cichorium inty- 

 bus) , common mustard (Brassica arvensis), mullein (Verbascum 

 thapsus) and also V. blattaria, and toadflax (Linaria vulgaris). 

 It is not uncommon to find in clearings of the forest the small 

 Kenilworth ivy (Linaria cymbalaria), the common pansy (Viola 

 tricolor), the petunia (Petunia grandi flora) , the dead nettles (La- 

 mium amplexicaule and L. album), ox-eye daisy (Chrysanthemum 

 leucanthemum) , hemp nettle (Galeopsis tetrahit), foxglove (Digi- 

 talis purpurea) , European bindweed (Convolvulus arvensis). The 



