VITALITY OF WEED SEEDS 



73 



Limit of Years during which 



Germinating Capacity was 



Retained. 



43 

 42 

 27 



26 

 25 



21 



18 



15 

 14 

 13 



12 

 10 



9 

 8 

 6 

 5 

 4 

 3 



Number of Species. 



i (Leguminosae). 



i (Leguminosae). 



7 (5 Leguminosae, 

 i Malvaceae, 

 i Tiliaceae). 



4 



4 



4 



I 



2 



I 



5 



2 



4 



2 

 70 



3 



3 



9 



97 



It is thus seen that the majority of seeds do not survive 

 for many years under ordinary conditions of storage, and that 

 eight and three years seem to be the critical .periods for a 

 large number of plants. The actual periods of survival for 

 the wild plants and farm weeds tested in these experiments 

 may prove interesting : 



English Name. 



Gorse 



Greater bindweed 



Fool's parsley 



Scarlet pimpernel 



Burdock 



Caraway 



Wild carrot 



Catmint 



Hemlock water-dropwort 



Broad-leaved dock 



Bladder campion 



Common vetch . 



Hemlock . 

 Narrow-fruited com salad 



(i) Bryonia dioica 



(2\ Hypericum hirsutiim 



(3) Plantxgo medii 



(4) Tragopogon porrifolius 



(5) Valenana officinalis 



(6) Verbascum thapsus 



White bryony . 

 Hairy St. John's wort 

 Hoary plantain . 

 Purple salsify 

 Common valerian 

 Great mullein 



Number 



of 

 Years. 



15 



