io4 



moRpMologv 



Fig. 96. 



7ii' 

 -Floral Diagram 



whorls and their segments are shown on a series of 

 concentric circles, as in fig. 96. In this figure the 

 dot at the top of the diagram represents the axis on 

 the side of which the flower is 

 borne, so that the side of the 

 diagram nearest to the dot re- 

 presents the POSTERIOR part of 

 the flower, and the side farthest 

 from the dot the anterior 

 part. The vertical plane pass- 

 ing through the centre of the 

 diagram and through the dot 

 is known as the median plane 

 {m, m), which divides the flower 

 into two equal and similar halves, right and left. The 

 vertical plane passing through the centre and cutting 

 the median plane at right-angles is known as the 



^ LATERAL PLANE {I, I), which 



divides the flower into two 

 equal and similar halves, pos- 

 terior and anterior. The two 

 vertical planes which bisect the 

 angles formed by the median 

 and lateral planes are known 

 as the diagonal planes {d, d\ 

 d', d'), each of which divides 

 the flower into two equal and 

 similar halves. Thus the dia- 

 gram represents a polysym- 

 metrical or actinomorphic com- 

 plete hermaphrodite flower. 

 Similar diagrams may be constructed of monosym- 

 metrical or zygomorphic flowers, as in fig. 97. The 

 diagrams further indicate whether the segments of 

 a whorl are free or coherent, and also whether they 



..-aZ. 



Fig. 97.— Diagram of Papilion- 

 aceous Flower (zygomorphic) 



ni, Median plane, a, Sepals. 

 sd. Standard, al, Alas, k, Keel, 



