294 



BOTANY. 



thin scales, as in Gladiolus. In tlie huU> the short stem (usually not 

 much thickened) is covered with thickened scales, as in the onion. 



§ 2. The Root. 



Form — Most roots are cylindrical, or nearly so, in form. When 

 of this form and quite small, they are thread-like {filiform or fibrous). 

 Many fleshy roots are conical (Fig. 181); others are spindle-shaped 

 {fusijorm), as Fig. 182; and still others are turnip-sliaped {napiform), 

 Fig. 183. When a main root extends perpendicularly downward 

 from the plant, it is called a tap-root. 



Fig. 181. Fig. 182. 



Conical root. Spindle-shaped root. 



Fig. 183. 

 Turnip-shaped root. 



Size — Make measurements of the root as for the stem. 



Surface — Examine the surface of the smallest roots : observe the 

 very minute down-like root-hairs. The surface of the large rootlets 

 is smooth ; then as the roots grow older the surface becomes more or 

 less roughened. 



Color — While the youngest rootlets are usually white, as they 

 grow older they generally become yellowish or brownish on the 

 surface. 



Structure — Roots may be soft in structure, or they may be woody; 

 the former may be^«%, as in the turnip, or thread-like, as in wheat 

 and oats. The wood and bark resemble those of the stem, but the 



