250 
THE ROOT 
determine where growth is most rapid as shown by increased distances 
between marks. 
Test roots for the presence of starch, sugar, and protein, using the 
tests suggested for seeds. Make a report on what you find. 
In what direction do roots usually grow ? Try to make them grow 
in some other direction. Write what you did and show by drawings 
what success you had. 
Draw aerial roots of an ivy stem. 
Draw a cluster of fascicled roots of a dahlia or a buttercup or an 
anemonella. 
SUGGESTIONS FOR HOME WORK 
Pull weeds and examine the roots. Which have tap roots? Why 
do they flourish better than the plants around them? 
Cut a piece of thick sod with a sharp spade or trowel. How many 
grass plants in a square two inches on a side? What kinds of roots 
has grass? Wash the dirt away carefully and measure the extent of 
the root system. Compare it with the part aboveground. Do the 
same with other plants than grass. 
On how many nodes of a corn stem do prop roots grow ? What is the 
effect of “ hilling up” corn on the production of prop roots? 
Place willow twigs in water. Watch the growth of adventitious 
roots, noting especially the root caps. Do duckweed and other floating 
plants have root caps? Account for what you find. 
Examine a large number of roots and report. 
Roots All 
Under¬ 
ground 
Roots not 
All Under¬ 
ground 
Primary 
Roots 
Fibrous 
Roots 
i 
Aerial 
Roots 
Dandelion. 
Plantain . 
Carrot . . 
Dahlia . . 
Com. . . 
Ivy . . . 
FORMS OF ROOTS 
Tap or primary roots — adapted to penetrate the soil, 
deeply enabling them to secure water when plants with 
different roots cannot. Adapted also to the storage of food. 
