160 



HORTICULTURE FOR SCHOOLS 



First two cells are formed, next four, then eight, and this 

 dividing continues until there are many cells, resulting 

 finally in the seed with its embryo 

 plant. Pollination and fertilization, 

 then, are both necessary for the 

 formation of seed. 



258. Organs essential for seed 

 production. Only two organs are 

 necessary for the production of seed, 

 the pistil (Fig. 102) and the stamens. 

 These, therefore, are called the essen- 

 tial organs of the flower. The calyx 

 and corolla, called together the 

 perianth, though frequently of service, 

 are not necessary for seed production, 



and in flowers of man y p jants either 



' or both is wanting. While 

 and P istils are necessary 

 the for seed production, both need not 

 be present in the same flower or 

 even on the same plant. A flower having both essential 

 organs, as the cherry blossom, is said to be perfect. 

 One possessing either stamens or pistils but not both 

 is imperfect. Flowers possessing stamens only are 

 staminate, and those having pistils only are pistillate. 1 

 When stamens and pistils are borne separately in different 

 flowers and both types of flowers occur on the same indi- 

 vidual, the plant is monoecious. 2 Such a plant, of course, has 

 no perfect flowers. Indian corn, pumpkins, cucumbers, 



1 The strawberry is an example of a plant possessing these various types 

 of flowers. Many varieties of strawberry plants produce perfect flowers. 

 Others have imperfect blossoms, containing pistils with imperfect or very 

 few stamens. Strawberry plants with imperfect flowers containing stamens 

 only are rarely found because staminate flowers do not produce fruit and 

 plants having them are not cultivated. 



2 "Monoecious" means belonging to one household. 



