loe 



OKGANOGEAPHY. 



Fig. 205. 



and ultimately forms an in-' 

 dependent plant, as in the 

 former instances. Plants thus 

 producing suckers are said to 

 be surcidose. Good examples 

 of this form of stem are seen 

 in the Kose, the Raspberry, 

 and the Mint {fig. 207). ^ The 

 sucker can scarcely be said to 

 differ in any essential particu- 

 lars from the stolon, except 

 that it is originally subter- 

 ranean, and ultimately becomes 

 aerial, while the stolon is first 

 aerial and then subterranean, 

 e. The Rhizome or RootstocJc. 

 (Figs. 208 and 209.)— This 

 is a prostrate thickened stem 

 or branch running along the 

 surface of the ground, or more 

 generally partly beneath it, 

 and giving off roots from its 

 lower side, and buds from its 

 These stems sometimes creep for a long distance in this 



Fig. 205. Plant, showing the process 

 of layering. 



upper, 



way, and have their upper surface marked by scars (fig. 209, c, c) 

 produced by the falling oflf of former leaves or herbaceous stems 

 Such stems are found in the Iris, Sweetflag, Ginger, Solomon's 

 Seal, and many other plants. The name rhizome is applied 



Fig. 206. 



Fig. 207. 



Figs. 206 and 207. Suckers of a 

 species of Mint, &c. 



by many botanists to all stems of a like nature and appearance 

 to it, whether aerial or subterranean. This stem forms, therefore, 

 a natural transition to the description of subterranean stems. 



