THE HOOT. 
31 
Fig. 18 
wliolly subterranean. This root, by the fibers spreading and 
interlacing themselves, renders a soil more permanent. Hol- 
land would be liable to be washed away by the action of water, 
were not its coasts bound together by these creeping plants, 
which will grow in sandy, light soils, that scarcely produce any 
other vegetation. 
The Grcmulatedroot (Fig. 17) con- Fig. i7. 
sists of little bulbs or tubers^ strung 
together by a thread-like radicle, 
as in the common wood-sorrel. 
By some, this is called monili- 
form^ from monile^ a beaded 
necklace. The potato and other tubers are by late botanists 
classed as subterranean sterns^ capable of developing leaf-buds ; 
these may consist of one tuber ; as in the potato (Fig. 18, a) ; or 
of many^ connected by fila- 
ments, as in the artichoke 
(5). These tubers are reser- 
voirs of moisture, nourish- 
ment, and vital energy. The 
potato is an excrescence, 
proceeding from the real 
root. It is a singular fact that this nutritious substance is the 
product of a plant whose fruit is poisonous. The eye in the 
] otato is a bud. The root of some of the orchis plants (Fig. 
18, c) consists of two ovate tubers ; these roots are said to be 
tuberiferous. 
b. Fig. 19, at a, shows a root of the Sph-anthes, 
one of the orchis tribe of plants. It bears a mass 
of crowded, club-shaped tubers : this is called a 
grumose root. At 6 is a fasciidated tuberous 
root, as in the dahlia, peonia, and asphodel. At 
c, the tubers are suspended from the caudex, as 
in the root of the Spiroea filipendida. 
Fig. 19. 
36. Bulbs. — ^These are subterranean 
leaf-buds covered with scales arising 
from a shortened axis. From the cen- 
ter of the bulb a shoot or herbaceous 
stem is produced, which dies down. 
JSTew bulbs (called turions) are produced from the subterranean 
axis, formed like buds in the center of a scale. The new 
bulb sometimes remains attached to the parent bulb, and sends 
up an axis and leaves, sometimes forms an independent plants 
The new bulb feeds on the parent one until it is wholly ab- 
sorbed. 
Granulated root— Tubers not the real root.— 36. Bulbs. 
