92 STRUCTURAL BOTANY. [78. 



CHAPTER XVII. 



FORMS OF SCALE-BEARING STEMS. 



230. The Scale-bearing stems are those forms 

 which, with internodes partially or not at all developed, 

 and generally clothed with scales for leaves, scarcely 

 emerge from the soil. They are the creeper and rhi- 

 zoma (developed), the crown, tuber, corm, and bulb 

 (undeveloped). Their forms are singular, often dis- 

 torted in consequence of their underground growth and 

 the unequal development of the internodes. They 

 commonly belong to perennial herbs, and the principal 

 forms are described as follows ; but intermediate con- 

 necting forms are very numerous, and often perplexing. 



257, Creeper of " Nimble Will " or Witch-grass ; a, Bud ; bb, bases of culms. 



231. THE CREEPER is either subaerial or subterra- 

 nean. In the former case, it is prostrate, running and 

 rooting at every joint, and hardly distinguishable other- 

 wise from leafy stems ; as the Twin-flower, the Par- 

 tridge-berry. In the latter case, it is more commonly 

 clothed with scales, often branching extensively, root- 

 ing at the nodes, exceedingly tenacious of life, extend- 



