1 88 BOTANY FOR BEGINNERS CHAP. 



floral-leaves are then called perianth-leaves. In most 

 monocotyledonous plants it is usual to speak of the two 

 whorls calyx and corolla as a perianth, as in the Hyacinth, 

 Tulip, and Daffodil. If the leaves of the perianth are distinct, 

 it is polyphyllous, and if united gamophyllons. If the stamens 

 are united to the leaves of the perianth, they are epiphyllous. 

 When the perianth is coloured like petals it is said to be 

 petaloid. 



Floral Formulae. The number and arrangement of the 

 floral leaves can be clearly represented by floral formulae. In a 

 floral formula the whorls are represented by letters, and the 

 number of leaves in the whorl by corresponding figures, or ii 

 the numbers are large by oo . The number of rows of leaves is 

 represented in a whorl by + coming between the corresponding 

 figures. The cohesion or union of the leaves in a whorl is 

 indicated by ( ), the adhesion by [ ] ; and superior organs are 

 shown by a line below the corresponding figure, and when 

 inferior by a line above the figure. 



If the flower is zygoinorphic or irregular the sign \ is 

 added. The letters used to represent the whorls are P = peri- 

 anth, K = calyx, C = corolla, A = andrcecium, G = gynoecium. 

 The following are examples of floral formulae. 



Buttercup K5, C5, A oo, G oo. 



Apple blossom. ..[K(s), GS, A oo,] G (5). 



Foxglove f K(5), [C(s) A 4,] G (2). 



Primrose K( 5 ), [C( 5 ), AS,] G (5). 



Tulip PS + 3, A 3 + 3 , G(3). 



Floral Diagrams. The parts of which the flower consists 

 can be shown in a graphic manner by constructing a ground 

 plan or map of the flower. To gain an idea of the arrangement 

 of the whorls in a flower, cut across a flower bud so as to 

 separate the sepals, petals, stamens, and pistil. If the cut 

 surface of the flower is examined the successive floral whorls 

 will be seen in their proper position. The sepals will form the 

 outer circle and the pistil the inner one, and between these the 

 stamens and petals come. To construct a floral diagram make 

 the number of rings required with a pair of compasses, and on 

 the rings show the position of the floral leaves. Fig. 204 is an 

 example of a floral diagram. 



