IV] 



DISPLACED BRACTS, ETC. 



39 



of which they are characteristic. In Boraginacese, Cras- 

 sulaceaB, Helianthemum, Cuphea, &c., we find other striking 

 examples of such displacements. 



Other causes of complexity of inflorescences, due to 

 torsions, the pressure of neighbouring organs, deflexions, 

 &c., must be passed over here. 



Fig. 13. Umbellate Cyme (Polychasium) of Elder. 



It will be evident from the foregoing account that 

 there are two principal aspects of an inflorescence; the 

 purely formal one, where any elongated axis bearing 

 unifloral pedicels of about equal length is regarded as 

 a raceme, and any axis bearing lateral flowers on pedicels 

 of graduated lengths, bringing the flowers to a more 



