STRUCTURE.] 



CHEEPING STEM. 



181 



creeps along horizontally below the surface of the earth, 

 emitting roots and new plants at intervals, as in Couch grass 

 (Triticum repens.) It differs in nothing whatever from the 

 rhizome, except in being subterranean. This is what in com- 

 mon parlance is called a creeping root. It is one of those 

 provisions of nature by which the barren sands that bound 

 the sea are confined within their limits ; most of the plants 

 which cover such soils being provided with subterranean 

 stems of this kind. It is also extremely tenacious of life, the 

 buds at every node being very excitable and capable of 

 rapidly renewing the existence of a wounded individual; 

 hence the almost indestructible properties of the Couch 

 grass, and similar plants, by the ordinary operations of hus- 

 bandry : divisions of its creeping stem, by cutting and tearing, 

 producing no other effect than that of calling new individuals 

 into existence as fast as others are destroyed. A creeping 

 stem is in reality a true Vegetable Hydra, and one of the 

 Sedges, Cyperus Hydra, has obtained its name from the 

 invincible property which it possesses of producing a crop of 

 new heads as soon as one is cut off. 



Vulneribus fecunda suis erat ilia, nee ullum 

 De comitum numero caput est impune recisum, 

 Quin gemino cervix herede valentior esset. Ov. 



The term soboles is applied by Link and De Candolle to the 

 sucker of trees and shrubs. (See Surculus.) 



Of the AERIAL stem, the most remarkable forms are the 

 following : 



