HOW PLANTS MABRY. 



89 



in the harebell and the gentian, it has five 

 points, or lobes, unit it at the base into a single 

 piece (Fig. 17). Last of all, outside the corolla 

 again comes another row or layer, called the 

 calyx, which sometimes consists of five separate 

 leaves or sepals, as in the dog-rose and the butter- 

 cup, but sometimes has five points, welded at 

 the base into one piece, as in red campion and 



FIG. 17. FLOWER OP A SHRUBBERY PLANT, WEIGELIA, 

 WITH THE PETALS UNITED INTO SINGLE COROLLA. 



I. Entire flower. II. The same, with part of the 

 corolla cut away. III. and IV. A stamen, fe, 

 calyx ; b, corolla ; s, stamen ; a, anther of the 

 stamen ; g and ??, parts of the pistil. 



convolvulus. It is these last comparatively 

 unessential but very conspicuous parts that 

 most people think of when they say " a flower.' 1 



What is their use ? Well, they are not essen- 

 tial, like the pistil and stamens, because many 

 flowers, perhaps, even most flowers, do without 



