ARRANGEMENT OF FLOWERS ON THE STEM 191 



203. Terminal Flowers ; Determinate Inflorescence. - 

 The terminal bud of a stem may be a flower-bud. In this 

 case the direct growth of the stem is stopped or deter- 

 mined by the appearance of the flower ; hence such plants 

 are said to have a determinate inflorescence. The simplest 

 possible case of this kind is that 



in which the stem bears but one 

 flower at its summit. 



204. The Cyme. Very often 

 flowers appear from lateral (axil- 

 lary) buds, below the terminal 

 flower, and thus give rise to a 

 flower-cluster called a cyme. 

 This may have only three flowers, 

 and in that case would look very 

 much like a three-flowered 

 umbel. But in the raceme, 

 corymb, and umbel the order of 

 flowering is from below upward, 

 or from the outside of the clus- 

 ter inward, because the lowest or the outermost flowers 

 are the oldest, while in determinate forms of inflorescence 

 the central flower is the oldest, and therefore the order of 

 blossoming is from the center outwards. Cymes are very 

 commonly compound, like those of the elder and of many 

 plants of the pink family, such as the Sweet William and 

 the mouse-ear chickweed (Fig. 137). They may also, as 

 already mentioned, be panicled, thus making a cluster 

 much like Fig. 136, A. 



FIG. 137. Compound Cyme of 



Mouse-Ear Chickweed. 

 t, the terminal (oldest) flower. 



