Fig. 96.— Weed seeds: 1, Night-flowering catchfly (Silene erectifolia) ; 2, Sheep's sorrel 

 (Rumex acetosella) ; 3, Curled dock {Humcx crispus); 4, Pennsylvania sniartweed (Polygonum 

 pennsylvanicum); 5, Lamb's quarter {Chenopodiuvi album); 6, Tumbling pigweed {Ama- 

 ranthus retroflexus) ; 7, Peppergrass (Lepidium virginicum) ; 8, Field cress (Lepidium cam- 

 pestre); 9, Yellow trefoil (Medicago lupulina); 10, Evening primrose {Onagra biennis); 11, 

 Wild carrot (Daucus carota); 12, Rugel's plantain (Flantago Rugelii); 13, Huckhorn (Flan- 

 tayo lanceolate); 14, Ox-eye daisy {Chrysanthemum leucatithemum) ; 15, Canada thistle (CnicUs 

 arvensis); 16, Bull thistle (Cnicus lanceolatus); 17, Yarrow {Achillea millefolium); 18, Dan- 

 delion {Taraxacum officinale); A, ventral side; B, dorsal side. 1, Caryophyllacea?; 2-4, 

 Polygnacese; 5, Chenopodiacese; 6, Amaranthacese; 7-8, Cruciferae; 9, Leguniinosae; 10, 

 Anagracea;; 11, Umbellifera;; 12-13, Plantaginaceae; 14-18, Compositse. 



