57 



like this which have their ovules uncovered are called Gymno- 

 sperms (naked seeded plants), while other plants having their and Anglos 

 ovules enclosed in an ovary are distinguished as Angiosperms. P 6 8 - 



53. When studying flowers it 



is convenient to be able to shortly and clearly express Di , grarrs 

 on paper the number, relative positions and other Floral 

 characteristics of the floral parts, instead of giving and Short- 

 long written descriptions. This can be done by floral hand- 

 diagrams and formulae. A floral diagram is a plan of the 

 flower in which the position of the various floral parts is in- 

 dicated by a diagramatic cross-section. To indicate the 

 posterior and anterior sides of the flower, the position of the 

 bract, in the axil of which the flower is borne, must be shown 

 .and of the main axis from which the flower springs. 



In floral formulae the following equivalents are used: 



K=calyx (sepals). 

 C= corolla (petals). 

 P = perianth. 



A=andro3cium (stamens). 

 G = gynoacium (carpels). 



The following examples will indicate how formulae are 

 ;<written : 



G (3). The flower has a polyphyllous perianth 

 of 6 leaves, in two whorls, each of 3 leaves. 

 There are 6 free stamens, also in two 

 whorls, each of 3, and a syncarpous, 

 infeiior gynoecium of 3 carpels. Nothing 

 being said to the contrary the flower is 

 regular. 



5 A < Goo. There are here 5 free sepals and 5 free 

 petals, while the stamens and carpels are 

 too numerous for easy counting. The 

 stamens are free and the gyncecium apocar- 

 pous and superior. 



A 5 A(s + 5) GI. Here there is a gamosepalous calyx 

 of 5 sepals, a zygomorphic corolla of 5 

 free petals, 10 stamens with their fila- 

 ments united into a tube and a gyncecium 

 of one superior simple pistil. 



