ABNORMAL INFLORESCENCE. 



225 



er, is similarly prolonged by a secondary branch, that by a third, 

 and so on ; as is shown in the 

 diagram, Fig. 255. Such 

 forms of inflorescence, which 

 we may observe in Drosera, 

 and in most Sedums and Bo- 

 raginacese, imitate the raceme 

 so nearly that they have com- \" 



monly been considered as of 

 that kind. They are distin- 

 guishable, however, by the 

 position of the flowers opposite 

 the leaf or bract, or at least 



out of its axil ; while in the raceme, and in every modification of 

 centripetal inflorescence, the flowers necessarily spring from the 

 axils of the bracts. But if the bracts disappear, as they commonly 

 do in the Forget-me-not, &c., the true nature of the inflorescence 

 is not readily made out. The undeveloped summit is usually 

 coiled in a spiral or circinate (257) manner, gradually unrolling 

 as the flowers grow and expand, and becoming straight in fruit. 

 On account of this coiled arrangement, such cymes or false ra- 

 cemes are said to be helicoid, or scorpioid. 



407. The cyme, raceme, head, &c., as well as the one-flowered 

 peduncle, may be produced, either at the extremity of the stem or 

 leafy branch (terminal), or in the axil of the leaves (axillary). 

 The case of a peduncle opposite a leaf, as in the Poke (see Ord. 

 Phytolaccacese), the Grape-vine, &c., is just that illustrated in Fig. 

 255, except that in these cases the peduncles bear a cluster of flow- 

 ers instead of a single one. The tendrils of the vine (Fig. 134) 

 occupy the same position, and are of the same nature, so that they 

 are not incorrectly said to be sterile and modified peduncles. In 

 a growing Grape-vine, it is plain to see that the uppermost tendril 

 really terminates the stem ; and that the latter is continued by the 

 growth of the axillary bud situated between the petiole and the 

 peduncle ; the branch thus formed, assuming the same direction 

 as the main stem, and appearing to be its prolongation, throws the 

 peduncle or tendril to the side opposite the leaf. 



408. The extra- axillary peduncles of most species of Solanum 

 are to be similarly explained. They are really terminal pedun- 



FIG. 254, 255. Plan of two modifications of helicoid cymes or false racemes. 



