THE HORTICULTURAL SOCIETY OF NEW YORK 



The absence of stamens in the flowers of a clonal variety of strawberry, 

 as shown at the right above for a flower of the Crescent variety, clearly indi- 

 cates the need for cross-pollination. Only varieties which have perfect 

 flowers, as the Klondyke shown at the left, are self -pollinating and self- 

 fruitful. Interplanting imperfect- with perfect-flowered varieties provides 

 for the necessary cross-pollination. There are various grades of intersexes 

 in strawberries aside from the two fruitful types here shown. 



In the period of early strawberry growing, roughly from 1820 to 1855, it 

 was very generally believed that the differences in the self-fruitfulness of 

 varieties of the strawberry were induced by differences in culture and 

 climate. Strawberry growing was a rather uncertain business until the 

 imperfect type of flower was recognized as a character of certain clonal 

 varieties and the practice of interplanting was established. 



nent because of vegetative propagation- They are quite apart from 

 the unfruitfuhiess that arises from lack of pollination or from lack 

 of proper fertilization. 



Among the many cultivated plants (and vv^ild as well) there are 

 various types of sterility ; the non-blooming condition, sterility 

 from hybridity, and sterility accompanying double flowers fre- 

 quently render plants decidedly or fully sterile in the true sense of 

 the term. Such plants may be grown as ornamentals and be 

 propagated vegetatively. Their sterility, however, does not arise 



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