644 
PHANEROGAMS. 
regard to the relationships here suggested, the flowers becoming diclinous from 
the stamens in the female flowers developing as sterile staminodes, which may be 
considered as the first step towards abortion, while in the male flowers the three 
carpels are replaced by as many fertile stamens (Payer). 
Fig. 432.— Diagtani of (Anacardiacea;). ' FiG. 453.— Diagram of Crö^ö/Äöra (Euphorbiaceae), « female, 
f> male flower. 
Reference was made in the Introduction to Angiosperms (pp. 6oi, 6io) to the 
interposition of a whorl of stamens between the members of a previously formed 
staminal whorl; and it was mentioned that the interposed whorl has sometimes not 
Fig. 454.— Diagram of pentamerous Ericaceae and Epacridere. FiG. 455.— Diagram oi .'Esciihis (Hippocastanes). 
the full number of members. These phenomena occur in various large groups of 
Dicotyledons \ In Fig. 454 the five stamens of the decandrous flower of the group 
of Bicornes which are interposed as a whorl of full number within the first whorl 
Fig. 456.— Diagram of Primulaceae. FiG. 457.— Diagram of Vitis (Ampelideae). 
are indicated by the lighter colour. The same is the case with the larger number of 
Gruinales, among which however the Balsamineae possess only the typical five 
stamens; the Linese and the genus Erodium have five additional rudimentary 
stamens interposed between them ; while in Peganum Harniala and Monsonia the 
^ Payer's figures show that the interposed whorl, although of later origin, is sometimes exterior 
to the typical whorl. The main point is that the position and number of the other parts of the 
flower are exactly as if there were no interposed whorl. 
