124 



THE BOOK OF NATURE STUDY 



The plant is vegetatively reproduced by bulbils, i.e. small 

 buds which develop at the base of some of the pinnae of the lower 

 leaves and grow up into new plants. These bulbils, while they 

 spread the plant in its immediate neighbourhood, are not suited 

 to disperse the plant widely, and this must result from seed- 

 production. 



THE SWEET VIOLET (Viola odorata, L.). 



A number of different species of Viola grow wild in Britain, 

 while others with more showy flowers are in cultivation. The 



Dog Violet (Viola canind) and 

 the Wild Pansy (Viola tricolor) 

 are, together with the Sweet Violet, 

 the most familiar of our wild 

 species. The numerous garden 

 varieties of the cultivated Pansy 

 have sprung from a foreign species, 

 Viola altaica y and other cultivated 

 forms have been derived from 

 Viola tricolor. All these plants, 

 while differing in details, are suffi- 

 ciently alike in their vegetative 

 organs, in the construction of the 

 flower, and in the mode of polli- 

 nation for the description of the 

 Sweet Violet that follows to be 

 of some assistance in their study. The description will, of 

 course, only apply in detail to the Sweet Violet. 



This species grows wild on grassy banks in the southern 

 counties of England, and is found less commonly farther north. 

 It is also extensively cultivated for the sake of its scented flowers, 

 which are on sale throughout the winter months and can thus 

 be easily obtained for study. The plant is a perennial, and has 

 a short, stout, woody stem which grows on at the summit year 

 after year, producing each spring a rosette of leaves inserted 

 close together on the stem (Fig. 63). A plant derived from 

 seed has a main root, but in those which have been produced 

 vegetatively in the manner described below the roots spring 



FIG. 63. Plant of the Sweet Violet. 

 (After Baillon.) 



