MORPHOLOGY OF HIGHER PLANTS. 331 



on the other hand, develop flowers continuously for many (or at 

 least several) years and also produce subterranean shoots, such 

 as creeping rhizomes, tubers, bulbs, etc. 



FIG. 189. Upper portion of rhizome of Gentiana lutea showing the structure of terminal 

 buds: A, terminal bud cut open to show the foliage leaves (b), which lie close to one another, 

 leaving only a narrow canal (s) in the middle. B, four-angled bud removed from A, showing 

 the foliage leaves having a strongly developed basal region (s) and relatively small lamina (sp) . 

 C, a small bud removed from the axis of the young leaves (B). D, upper portion of rhizome 

 of a flowering plant showing the stem base (S) and several buds (k). E, upper portion of 

 rhizome of a plant 6 years old showing scar (n) of the flowering branch and the strongly 

 developed side branches with terminal buds (k). The annulations are scars formed from 

 the bud scales which have dropped off. After Meyer. 



The roots of annuals, biennials, and perennials differ in a num- 

 ber of particulars. In the annuals, belonging to the monocoty- 

 ledons, the roots are fibrous, possessing numerous lateral branches, 

 whereas in the annuals belonging to the dicotyledons only the 



