224 



THE FLOWER. 



421. All the organs of the flower are situated On, or grow out of, 

 the apex of the flower-stalk, into which they are said, in botanical lan- 

 guage, to be inserted, and which is called the Torus, or Reckptaclb. 

 This is the axis of the flower, to which the floral organs are attached 

 (just as leaves are to the stem) ; the calyx at its very base ; the 

 petals just within or above the calyx ; the stamens just within the 

 petals ; and the pistils within or above the stamens (Fig. 343). 



i c 422. Such is the struct- 



ure of a complete and regu- 

 lar flower ; which we take 

 as the type, or standard of 

 comparison. The calyx 

 and corolla are termed pro- 

 tecting organs. In the bud, 

 they envelope the other 

 parts : the calyx sometimes 

 forms a covering even fof 

 the fruit ; and when it retains its leaf-like texture and color, it as- 

 similates the sap of the plant with the evolution of oxygen gas, in 

 the same manner as do true leaves : the corolla elaborates honey or 

 other secretions, for the nourishment, as is supposed, of the stamens 

 and pistils. Neither the calyx nor corolla is essential to a flower, 

 one or both being not unfrequently wanting. The stamens and pis- 

 tils are, however, essential organs, since both are necessary to the 

 production of seed. But even these are not always both present in 

 the very same flower ; as will be seen when we come to notice the 

 diverse forms which the blossom assumes, and to compare them with 

 our pattern flower. 



Sect. II. The Theoretical Structure or General Mor- 

 phology OP the Flower. 



423. To obtain at the outset a correct idea of the flower, it is 

 needful here to consider the relation which its organs sustain to the 

 organs of vegetation. Taking the blossom as a whole, we have 

 recognized, in the chapter on Inflorescence (377), the identity of 

 flower-buds and leaf-buds as to situation, &c. Flowers, consequently, 



FIG. 343. Parts of the flower of a Stonecrop, Sedum ternatum, two of each sort, and the 

 receptacle, displayed : i*, sepal ; 6, petal : c, stamen : d, pistil. 



