THE STEM OF VASCULAR PLANTS. 197 



underground, as Allium senescens. This last mode of 

 development of the stem is frequent in Iris, Amomum, 

 Acorus, &c. ; and this organ then receives the name of 

 Rhizoma, to indicate that it resembles a root, because it 

 is subterranean ; but it is a true stem, which remains 

 buried underground, producing true roots, and from its 

 apex leaves and annual shoots : these bear the flowers, 

 and frequently leaves ; they are like the annual stems 

 of perennial Dicotyledons, whilst the Rhizoma represents 

 the persistent stock, which, in the Asters and Poeonies, 

 &c. remains beneath or on a level with the surface of the 

 ground, and produces each year new floral shoots. 

 Although I have mentioned these facts in speaking of 

 stems in general, I have thought it right to return to 

 them here, both in order to show that the same prin- 

 ciples apply to all the stems of the Liliacese, however 

 different their forms may be, and to serve as an intro- 

 duction to the following Article. 



§ 3. — The Stem of the Bananas. 



It is usual to describe, imder the name of the Stem of 

 the Bananas, the cylindrical body which bears the leaves, 

 and is terminated by the cluster of flowers ; and under 

 the name of the Root is confounded all the subterranean 

 parts ; but when we examine these organs, and are 

 guided by analogy, we readily perceive — 1st, that the 

 subterranean part is composed of true roots, and of a 

 persistent rhizoma; 2d, that the elevated portion, which 

 perishes after each time of flowering, is a kind of false 

 stem, formed by the sheaths of the leaves which sur- 

 round the scape or floral peduncle, and are united to it. 

 These sheaths are, thus to speak, the petioles of the 



