74 THE STEM. 
181. The ruizoma, or rootstock, is a prostrate, thickened, 
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 angry gardener, since they are thus 
multiplied as many times as there are fragments. 
a. Repent stems of this kind are not, however, without their use. They fre- 
quently abound in loose, sandy soil, which they serve to bind down and secure 
against the inroads of water, and even of the sea itself. Holland is said to owe its 
very existence to certain repent stems, by which its shores are apparently bound 
together. Much of the surface of that country is well known to be even below 
the 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 arrraL stEMs belong the following varieties ;—caulis, 
runner, scape, vine, trunk, sucker, offset, and stolon. 
184. Cavtis (stem) is the term commonly applied to the aérial 
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 aenal 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 tun. Ex. strawberry. 
186. The scars is a stem which springs from the summit of 
the root, or rootstock, and bears the inflorescence of the plant, 
but not its foliage. TEx. 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. 
