CH. IV] 



CYMOSE INFLORESCENCES 



31 



Cyme, found in Hemerocallis, and the Gincinnus (Fig. 12, B) 

 or Scorpioid Cyme, of the Boragineae, which most people 

 would regard as forms of spikes and racemes until closely 

 examined ; or the Drepanium (Fig. 12, F) or Sickle-shaped 

 Cyme of the Rushes, and the Rhipidium (Fig. 12, D) or 

 Fan-shaped Cyme of the Iris, which have no close 

 analogies in our woody plants. 



ABC 



Fig. 10. Types of Cymes. A, a Dichasium built up of successive pairs 

 of opposite branches on the primary axis, each ending in the flower 

 (1, 2, 3, &c.) : if three or more branches arise together each time, it 

 becomes a Polychasium or Umbellate Cyme. B, a Drepanium, resulting 

 from the continued suppression of one of the branches, always on the 

 same side, in A. C, a Dichasium built up of successive pairs of alternate 

 branches, one on either side. The numbers give the order of succession. 



Passing to the simpler forms of cymose or definite 

 inflorescence, the first point to notice is that the elonga- 

 tion of the primary axis is rapidly arrested, because it 

 ends in a flower which opens before those on the 

 secondary axes do simply because it is developed earlier 

 and is therefore older. 



The simplest case of all is where the peduncle has 

 only one terminal flower, e g. the Poppy. If from the axils 

 of bracts below this terminal flower, branches should be 



