SOME LESSONS IN BOTANY 51 
Rhubarb, peonies, and the common grasses are herbaceous 
perennials. If the stem is woody, it lives over the winter, 
and we have a tree or shrub, the only difference 
between these being in their size. 
Tue Roots 
Tap Roots and Fibrous Roots. — Soon after 
the seedling stage of a growing plant is passed, 
the characteristic form of its root system becomes 
apparent, and then we generally find either one 
large main root, or merely a number of small, 
slender roots. In the first case we say the plant 
has a tap root; in the second case it has fibrous 
roots. ‘Tap roots grow straight down into the 
ground, sending smaller, lateral branches in all 
directions. Beets, carrots, alfalfa, dandelions, T4? Root 
and many other plants have tap roots. In some Meus, 
of them, as in alfalfa, this tap root reaches down to a great 
depth, which of course is an advantage in dry seasons. Fi- 
Fisrous Roots oF A Corn PLANT 
