74 THE STEM. 



181. Tlie RHizoMA, or rootstock, is a prostrate, tliickened, 

 rooting stem, either wholly or partially subterranean, often cov- 

 ered with scales, which are the rudiments of leaves, or marked 

 with scars, which indicate the insertion of former leaves, and 

 yearly producing both shoots and roots. Such is the thickened, 

 horizontal portion of the blood-root (Sanguinaria), sweet flag 

 (Calamus), and the bramble (Rubus). 



182. The CREEPER differs from the above only in size, consisting of slender 

 branches, exceedingly tenacious of life, extending horizontally in all directions, 

 and to considerable distances beneath the surface, sending out roots and branches 

 at intervals. The witch-grass (Triticum repens) is an example. Such plants 

 are a sore evil to the garden. They can have no better cultivation than to be 

 torn and cut in pieces by the spade of the angiy gardener, since they are thus 

 multiplied as many times as there are fragments. 



a. Ilcpcnt stems of this l^ind are not, however, without their use. They fre- 

 quently abound in loose, sandy soil, wliich they scne to bind down and secure 

 against the inroads of water, and even of the sea itself. Holland is said to owe its 

 verj- existence to certain repent stems, by which its shores are apparently bonnd 

 together. Much of the surfice of that country is well known to be even below 

 die level of the sea. To protect it from inundation, dikes of earth have been 

 built, with immense labor, along the coast. These dikes are overspread with a 

 thick growth of such plants as the mat-grass, or Arundo arenaria, the Carex are- 

 naria, and the Elymus arenarius, by the innumerable roots and creepers of which 

 they are enabled to resist the washing of the waves. 



183. To AEPaAL STEMS bcloug the following varieties; — caulis, 

 mnner, scape, vine, trunk, sucker, offset, and stolon. 



184. Caulis (stem) is the term commonly applied to the aerial 

 stems of herbaceous plants, which are annual in duration, and 

 destitute of woody tissue. Caulescent and acaulescent are con- 

 venient terms, denoting, the former the presence, and the latter 

 the absence of the caulis, or nerial stem. 



185. Runner. This is a prostrate, filiform stem, or shoot, ex- 

 tending itself along the surface of the ground, and throwing out 

 roots and leaves at its extremity, which become a new plant, 

 soon putting forth new runners in its ttirn. Ex. strawbelT}^ 



186. The SCAPE is a stem which springs from the summit of 

 the root, or rootstock, and bears the inflorescence of the plant, 

 but not its foliage. Ex. Sarracenia, daffodil, several species of 

 the Orchis, &c. The foliage of such plants is usually radical, 

 that is, springing from the root or subterranean stem. 



