BKACTS AND FLOEAL LEAVES. 



77 



(i.) When the main axis is long or fairly long, it may bear 

 stalked flowers, and is then a raceme (fig. 31). A good 

 example is the hyacinth, and here, as in 

 all indefinite flower clusters, the blossoms 

 open in acropetal order, so that the lowest 

 flowers have withered before the upper- 

 most ones are even open. Further in- 

 stances are found in foxglove, snapdragon, 

 wallflower, barberry (fig. 31), and currant. 

 The last two racemes are pendulous, owing 

 to the weaknesss of the main axis, while 

 bracts are absent in the wallflower. "Where, 

 as in hawthorn and edible cherry, the axis 

 is comparatively short, and the pedicels 

 farther from the apex are larger than those 

 nearer it, so as to bring the flower to about 

 the same level, we have a corymb. This 

 is only a variety of raceme. The flowers 

 here open centripetcdly, i.e., the outer ones 

 open before the inner ones, since they are first developed. 



FIG. 3] 



-Raceme of Bar- 

 berry. 



When 



'Fig. 32.— 

 Spike of Verbena. 



Fig. 33.— Spadix of Arum. i. Closed; 

 2. cut open. a. axis ; 6. spathe ;.;". 

 female flowers ; m. male flowers; 

 those above are aborted. 



an elongated main axis bears sessile flowers, a spike (fig. 32) is 



