ROSACEOUS PLANTS. 



S7 



wliicli constitute, as in Mallow, an epicalyx. The pistil 

 must be carefully examined. In this case there will be 

 found a conical elevation in the centre of the 

 flower, on the surface of which are inserted 

 : many separate carpels, much in the same way 

 :/ as in Buttercup. At maturity this elevated 

 ~ receptacle will have become greatly enlarged 

 and pulpy, with the real fruit, the ripened 

 Fig. 46. carpels, dotted over its surface (Fig. 46). 



51. Cherry or Plum. Here also the calyx, corolla, 

 and stamens are all adherent, and a hollow cup is formed, 

 in the bottom of which 



(but entirely free from 

 these parts) the pistil is 

 developed (Fig. 47). It 

 consists of a single carpel, 

 in which there are at first 

 two ovules, though gen- 

 erally but one seed is 

 ripened. The fruit is 

 called a drupe, the seed being surrounded by three distinct 

 layers: (1) a hard shell (the putamen), (2) a mass of soft 

 pulp, and (3) the outer skin. 



52. Crab- Apple. Here, as before, we have a gamo- 

 sepalous calyx, the lower part forming a tube. The five 

 petals are separate and inserted on the calyx, as are also 

 the numerous stamens. To understand the structure of 

 the pistil, make a vertical section through the centre of 

 the flower, and also a cross section. The cross section 



Fig. 47. 



Fig. 46. Vertical section of Strawberry. 



Fig. 47. Vertical section through flower of Cherry. (Gray.) 



