52 



ROSE^. 



[part I. 



its near ally the Dog rose(i?. canina), the sepals 

 (a) do not extend far beyond the petals of the 

 bud ; but in some species, as in Bosa cinnamonea 

 and its allies, the sepals are so large and long, 

 that they assume the character of little leaves, 

 The corolla is cup-shaped, and it is composed of 

 five equal petals, each of which is more or less 

 indented in the margin, as shown at h. In 

 the centre of the flower the receptacle forms a 

 kind of disk which completely fills the opening or 

 throat of the calyx ; in most species covering the 

 carpels and their styles and onlyleaving the stigmas 

 free, though in the Ayrshire rose {R. arvensis), 

 and its allies, the styles are united, so as to 

 form a column, which projects considerably above 

 the disk (seejir/. 21). 

 The pitcher - shaped 

 part of the calyxwhen 

 the corolla falls be- 

 comes the hip (Ji[/. 

 20 c), and serves as 

 a covering or false 

 pericarp to the nu- 

 merous bony carpels 

 or nuts which contain the seed. These nuts 

 are each enveloped in a hairy cover (see Jlf/, 

 20 d, and Ji^. 21 a,) and each contains only 

 one seed which it does not open naturally to 

 discharge : hence, the seeds of roses when sown 



Fig. 21.— Ovary of the Ayrshire 



ROSE WITH A DETACHED SEED. 



