FLESHY ROOT.
"I do not understand," said Ella, "how the root can suck up water! Are there holes in the root which stand for mouths?"
"The roots are covered with what we call fibrils or root hairs, and these are very delicate, and through their surfaces they take in the moisture. Now if you will examine this root of a young tree which Tom has pulled up for our lesson you will see that the root has branched, and every year the branches multiply and spread farther and deeper into the ground. Now notice that the branches grow smaller and smaller. Look through this microscope and you will see the tiny hair-like projections; these take up the moisture, and as there are so many of them upon every little rootlet, they take up a great deal. We call this a branching root; some roots are what we call fibrous. Tom, suppose you see if you can find a buttercup root and bring it here."
FIBROUS ROOT.
Tom sprang to do his mother's bidding, and soon returned with what looked like a hank of thread—long fibres bound together at the surface of the ground, at the top of what we call the axis of the plant. Mrs. Brown explained that the central stem is called the axis, and that the part which goes downward is the descending axis, and the part that shoots upward and bears the branches, is the ascending axis.
"You observe," she said, "that in the case of this plant there is no descending axis, the long fibrous roots spring from the collum or collar, which is the place where the root and stem join, or from the line of division between the ascending and descending axis. The fibrous roots are mainly for the purpose of absorbing nourishment for the immediate use of the plant, and this structure gives them greater surface by which to take up the moisture for rapid growth. Other roots serve an additional purpose. They store up food for the future growth of the plant, and such roots are called fleshy roots, and many of them are useful to us for food. In such the axis is long and thick and with only short branches and of course fewer fibrils."
"Now if we leave one of these fleshy roots—for instance the beet—in the ground through the winter instead of storing it in the cellar for table use, when spring comes the plant will begin to put forth a new growth, much more vigorous than that of the first year, and quite different. It will send up strong shoots bearing flowers and ripening seed. And all this will use up the food stored in the root, and when the seed has ripened the plant will die. This we call a biennial plant."
"The fibrous roots belong largely to annual plants, while the branching roots belong principally to the woody plants, as trees and shrubs. I heard Tom talking about transplanting trees. You should take great care not to injure the small roots and fibrils, for, by breaking or cutting off these, you lessen the absorbing power of the root."
"You spoke of annuals and another kind—those which live two years," began Ella.