44 



MANUAL OF BOTANY 



essential particulars from the stolon, except that it is originally 

 subterranean, and ultimately aerial ; whereas the stolon is first 

 aerial, and then subterranean. 



e. The Rhizome or rootstock {figs. 58 and 59). — This is a 

 prostrate thickened stem or branch running along the surface of 

 the ground, or more generally partly or entirely beneath it, and 

 giving off small roots or rootlets from its lower, and leaves and 

 buds from its upper side. These stems sometimes creep for a 

 long distance in this way, and have their upper surface then 

 marked by scars (fig. 59, c, c), which are caused by the falling 



Fig. 65. 



Fig. 66. 



Fig. 66. A portion of the stem of Pwisifiora qimdrmgiilaris v ». Tendrils. 

 Fig. 66. Part of tile stem of the Vine. i\ v, v. Tendrils. 



off of former leaves, or of aerial herbaceous stems or fiower- 

 stalks, by which character they may be commonly distinguished, 

 even when in a dried state, from true roots. Such stems are 

 found in the Iris, Sweet-flag, Ginger, Turmeric, Solomon's Seal, 

 Fern, and many other plants. In some cases these rhizomes are 

 placed in a vertical direction in the earth {erect rhinomes), and 

 they then bear a great resemblance to roots, as in the Devil's- 

 bit Scabious (Scabiosa snccisa), where such a rhizome is com- 

 monly but erroneously known as a. prcemorse root {fig. 61). 



The rhizome may continue to elongate at its apex through- 

 out its life as in the Bracken Fern, or the apex may grow out 

 *nto an aerial shoot, while a bud is formed laterally in the axil 



