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A TEXT-BOOK OF BOTANY. 



may be carried on) as well as flowers, and from the lower, surf ace, 

 roots (Fig. 182). 



While most rhizomes are perceptibly thickened, and more or 

 less fleshy when fresh, as Sanguinaria, in other instances they are 

 of the ordinary thickness of the overground stem. 



FIG. 184. Plant of spearmint (Mentha spicata) showing procumbent stems or leafy 

 runners from which roots are developed at the nodes, and one erect branch at the left from 

 which a new plant will be developed. 



There are some rhizomes that are excessively thickened, as 

 in the common white potato (Fig. 185), and these are called 

 TUBERS. The so-called " eyes " are small buds covered with 

 small, scale-like leaves which develop into shoots. Tubers should 



