SUNLIGHT FACTORIES 
55 
and pass it back to the main root—in this case 
the carrot. The main root has water-carrying 
tissues like a stem, and it sends the water up to 
the leaves. A root like a carrot is called a tap 
root because it goes straight down into the 
ground and “taps” the water supply. The dan¬ 
delion has this kind of root also. This is an 
interesting one to study because it usually has 
many more root hairs than the carrot. The tap 
root of the dandelion is much larger also. In 
roots of this kind the long thick part is chiefly 
for holding the plant in the ground and taking 
care of stored up food, while the root hairs 
absorb the water. These root hairs then pass 
this water back to the main root. 
Most smaller plants have a crooked, branched 
root that looks like a stem, and each branch has 
many hundreds of root hairs. These root sys¬ 
tems are of all sizes and shapes. Some of them 
are very shallow in order to get the rain from 
the surface of the ground. These do not make 
very good anchors and their plants are easily 
blown over. Roots like this are very satisfactory 
There are many dif¬ 
ferent root forms 
