30 



ELEMENTS OF BOTANY. 



The primary axis may terminate in a single flower, from whose axils 

 two secondary axes proceed, each terminating in a flower, with other 

 tertiary axes, and so on. This is a dichotomous (forked) cyme. 



Again, the primary axis terminating in a flower, subtended by a single 

 bract, from its axil proceeds a 'secondary axis terminating in like manner ■ 

 from its axil a tertiary, and so on. In this manner is produced the 

 scorpoid cyme or raceme, which seems to unroll as flowering pro- 

 ceeds (Fig. 51). 



*-T 



Fig. 50.— A cyme. 



Fig. 51.— A scorpoid cyme or raceme. 



In other cases still the cyme assumes a spicate or umbellate form. 



Both the fascicSe and glome rule are of a cymose character. In the 

 former the axes are somewhat lengthened and are regularly distributed ; 

 in the latter they are almost suppressed and very irregular. 



In determinate inflorescence the central flower always expands first, and 

 the outer or lower flowers follow in regular succession, so that there is a 

 movement from the centre toward the circumference ; hence this form of 

 inflorescence is termed centrifugal. 



