218 



THE INFLORESCENCE. 



ence to the centre. This mode of development uniformly takes 

 place when the flowers arise from axillary buds ; on 

 which account the indefinite mode of inflorescence is 

 also called the centripetal. 



388. In all the foregoing cases, the flowers are raised 

 on stalks, or pedicels. When these are wanting, or 

 very short, the spike or the head is produced. 



389. A Spike is the same as the raceme, except that 

 the flowers are sessile, or destitute of any apparent pedi- 

 cels ; as in the Plantain (Fig. 233). It is an indetermi- 

 nate or centripetal inflorescence, with the primary axis 

 elongated, and the secondary axes not at all elongated, 

 but terminated at their very origin by a flower. Two 

 varieties of the spike have received independent names, 

 viz. the Spadix and the Ament. 



390. A Spadix is a fleshy spike enveloped by a large 

 233 bract or modified leaf, called a SPATHE, as in Calla pa- 



lustris (Fig. 234), the cultivated Calla ^Ethiopica, Arum triphyllum, 

 or Indian Turnip (Fig. 235), and the Skunk Cabbage (see Araceae). 



391. An Ament, or Catkin, is merely that kind of spike with scaly 



FIG. 233. Young spike of Plantago major. 



FIG. 234-239. Forma of inflorescence. 234, 235. Spadix of Calla and of Arum, with the 

 spathe. 236. A raceme. 237. A cyme. 233. A panicle. 239. A corymb. 



