SEEDS AND SEEDLINGS 



127 



Fig. 89. — Weed seeds: 1, Night-flowering catchfly iSilene erectifolia) ; 2, sheep's sorrel 

 {Rumex acetoseUa) ; 3, curled dock {Rumex crispus) ; 4, Pennsylvania smartweed {Polygonum 

 pennsylvanicum) \ 5, lamb's quarter (Chenopodium album); 6, tumbling pigweed {Ama- 

 ranthus retroflexus) ; 7, peppergrass {Lepidiujn virginicum); .8, field cress iLepidium camr- 

 pestre)', 9, yellow trefoil {Medicago lupulijia); 10, evening primrose {Onagra biennis); 11, 

 wild carrot {Daucus carota); 12, Rugel's plantain {Plantago Rugelii); 13, buckhorn {Plan^ 

 toga Uinceolata); 14, ox-eye daisy (ChrysanthemuTn leucanthemum); 15, Canada thistle {Cni- 

 cus arvensis); 16, bull thistle (Cnicus lanceolatus); 17, yarrow {Achillea m.illefolium); 18, 

 dandelion {Taraxacum officinale); (a) ventral side; (fc) dorsal side- 1, Csiryophyllaeeae; 2-4, 

 PolygnaceEB; 5, Chenopodiace£e; 6, Amaranthaceae; 7-8, Cruciferffi; 9, Leguminosie; 10, 

 Anagracese; 11, Umbelfif ersp ; 12-13, Plantaginacesp ; 14-18, Compositse. 



