WEED MIGRATION 



741 



Fig. 558. Yarrow (Achillea millefolium). Common in the northern hemis- 

 phere. 

 (Drawing by Charlotte M. King.) 



Cyperus esculentus (northern nut grass) (As.) 



Epilobium angustifolium (fireweed) (As.). 



Erigeron acris (fleabane). 



Erysimum cheirantlioides (treacle mustard). 



Galium trifidum (bedstraw) (As.). 



Galium aparine (cleavers) (As.). 



Gnaphalium uliginosum (cudweed). 



Hierochloe borealis (holy grass). 



J uncus tenuis (wire-grass). 



Lepidium apetalum (peppergrass). 



Mentha arvensis (mint) (As.). 



Myosurus minimus (mouse-tail). 



Oxalis corniculata (field sorrel). 



