404 GENEKAL BOTANY 



chiloensis). Like most of the other fruits of this order the straw- 

 berry is therefore a product of the breeding and improvement of 

 wild plants by the methods of hybridizing and breeding recorded 

 in earlier chapters. Vegetative reproduction by means of run- 

 ners has already been explained in Part I and is there illustrated, 

 together with the acaulescent habit of these plants, in Fig. 76. 

 Flowers and fruit. The flowers in the strawberry are quite 

 similar to those of Caltha, with an elongated receptacle on which 

 the numerous stamens and the cluster of simple pistils are 

 arranged spirally (Fig. 255, a, 5). The flowers are usually per- 

 fect, but some commercial varieties have only pistillate flowers, 

 while others have pistils with few stamens (Fig. 255, e,/). In 



FIG. 255. Flowers and fruit of the strawberry (Fragaria) 



a, 6, surface and sectional views of a perfect flower; c, fruit; d, perfect flower; 

 e, f, imperfect flowers (e, pistillate flower ; /, staminate flower) 



planting such varieties care must be taken to have both pistillate 

 and pollen-bearing individuals in the same or in alternate rows. 



Cross-pollination is effected by insects, since the perfect flowers 

 are protogynous, the stigmas ripening before the stamens. Polli- 

 nation and fertilization in the strawberry, as in so many other 

 fruit-forming species, results not only in the development of the 

 seeds but also in great changes in the receptacle, by which it 

 becomes greatly enlarged and fleshy to form the fruit. The 

 seeds remain inclosed in the ovary wall, which dries and forms 

 a true achene. 



The fruit is therefore composed largely of fleshy receptacle, 

 with the hard achenes scattered over its surface and commonly 

 designated as seeds by those who eat the ripened fruit. The dis- 

 semination of the wild strawberry is undoubtedly facilitated in 

 nature by animals that eat the fruit and eject the dried achenes 

 and seeds with their excrements. 



