THE INFLORESCENCE 



73 



Reduction is usually superficially evident from comparison with re- 

 lated taxa and, in extreme reduction, when externally obscure, can 

 often be detected anatomically, as in Acer, where vestiges of the in- 

 florescence axis are present in the clusters of flowers of the soft maples, 

 and in Yicia, where the axis of an axillary raceme is buried in the 

 cortex of the mother stem beyond the attachment of the trace of a 



Fig. 31. Sketches of flowers and inflorescences of Vicia spp. and diagrams of 

 vascularization of the nodes. A, B, E, showing stages in flower reduction in raceme: 

 E, the surviving flower apparently borne on the main stem; C, D, and F, G, dia- 

 grams in longitudinal and transverse sections showing the anatomy of the nodes 

 of B and E, respectively. In F, the peduncle of the raceme has disappeared ex- 

 ternally, vestiges of its traces are seen buried in the main stem, and traces of the 

 flower are apparently derived independently of the inflorescence stele. 



proximal flower (Fig. 31), so that the flower of a secondary axis seems 

 to be borne on a primary axis. Similarly, in the well-known proteaceous 

 genera GreviUea and Baaksia, the flowers that appear to be borne on 

 the main (primary) axis of the inflorescence are borne on greatly re- 

 duced, hidden, secondary axes. 



A different type of reduction is that where the number of flowers re- 

 mains high but the axis system is greatly reduced. In Platanus, the 

 numerous flowers are crowded into heads; those of each major branch 



