THE FLORAL ^HOOT. 



431 



These lateral shncits usuall_v l)ramh and elongate so that the 

 terminal flowers on all the brandies reach near]}' the same height 

 as the terminal flower on the main shoot, forming a somewhat 

 flattened or convex topj of the flower cluster. This is illustrated 



Fig. 45,5- 

 Diajrrams rif c^'mose inflorescence. .4, dichasium; B, scorpioid cyme; C, heli- 

 coid c\-nie. (After Strasburger. ) 



in the basswood flower. The anthesis of the cyme is cenlrijiigal, 

 i.e., from the inside outward to the margin. But it is often more 

 or less mi.xed, since the lateral shoots if they bear more than one 

 flower are dimuniti^•e C}-mes and the terminal flower opens before 

 the lateral ones, ^^'here the flower cluster is ciuite large and 

 the branching quite e.xtensive, compound cymes are formed, as 

 in the dogwood, hydrangea, etc. 



831. The helicoid cyme. — Where succes.sive lateral branch- 

 ing takes place, and always continues on the same side a curved 

 flower cluster is formed, as in the forget-me-not and most mem- 

 bers of the borage family. This is known as a helicoid cyme 

 (fig. 453, C). Each new branch becomes in turn the "false" 

 axis bearing a new branch on the same side. 



832. The scorpioid cyme. — .4 scorpioid cyme (fig. 453, B) is 

 formed where each new branch arises on alternate sides of the 

 "false" a.xis. 



833. The forking cyme is where each "false" a.xis produces 

 two branches opposite, so that it represents a false dichotomy 

 (example, the flower cluster of chickweed). 



834. Some of these flower clusters are peculiar and it is diffi- 



