64 



THE ROOT. 



400. Forest trees, being less exposed to the assaults of the wind, are much less 

 firmly rooted than those in open situations. 



145. Fusiform (spindle-shaped). It consists of a thick, fleshy 

 caudex, tapering downwards, and also, for a short space, up- 

 wards. It sends off from the sides and extremity, thread-like 

 fibrils, which are in fact its true roots, since they alone absorb 

 nourishment from the ground. Ex. parsnip, radish. 



FIG. 20. 

 10, Orchis. 



Forms of the root ; 7, branching roots of a tree ; 8, root of Daucus ; 9, Oxalis j 



a. When the fusiform root divides into two principal branches, it is said to be 

 forked. When it tapers from the collum downwards its whole length, it is called 

 a conical or tap root. But its most remarkable variety is the 



b. Premorse, in which the caudex terminates abruptly below, 

 as if it had been bitten off (praemorsus). This is due to the 

 fact that the lower extremity perishes after the first year. Ex. 

 Viola pedata, and Scabiosa succisa. 



c. The napiform (turnip-shaped) root is another variety of the 

 fusiform, where the upper portion swells out, so that the diame- 

 ter is greater than the length. Ex. turnip. 



146. The fibrous root consists of numerous thread-like divis- 

 ions, sent off directly from the base without any caudex. Such 

 are the roots of most grasses, which multiply their fibres exceed- 

 ingly in a ligjit sandy soil. 



a. A fasciculated root is a variety of the fibrous, with some of 

 its fibres thickened, as in the crow-foot (Ranunculus), peony, 

 Dahlia, &c. 



147. A tuberous root consists of one or more fleshy knobs, 01 



