roots in their hard burrowing work a little cap of hard cells
is fitted over their tips. Little hairs grow all over them, whose
purpose is to help absorb moisture.

Some thick and fleshy roots are good to eat. They form many of our best
vegetables. Beets, turnips, parsnips, and carrots are such roots. They
belong to biennial or two-year plants. The first year they store up food
in their roots; the second year draw upon this food, and produce flowers
and fruit. They are named from their shapes. _Fusiform_, like radishes,
when thicker in the middle, tapering at both ends. Carrots are
_conical_, thicker at the top. Turnips bulge out in the middle, and are
_napiform_. When clustered like a dahlia the roots are _fascicled_. All
are _taproots_, or main roots. Besides these _primary_ roots there are
_secondary_. You may have noticed secondary roots springing from the
joints of a corn-stalk above ground. The wonderful banyan-tree sends
down roots from its branches, making new trees, until one tree is the
mother of a colony.

There are plants which take their nourishment from the air alone, and
not from the soil. They need roots as hold-fasts, not as drinking-cups.
Some lovely orchids grow in that way. Those leathery patches which you
have seen on old fence-rails and rocks are lichens. They have roots for
attachment only, and such are called _aerial_ roots.

Then there are _climbing_ rootlets. Look at the poison-ivy, but do not
touch it, and you will see it climbing over tree-trunks and fence-posts
by means of rootlets. The trumpet-creeper will show you the same thing.
These rootlets are very strong, as you will find if you try to pull, as
I did once, a trumpet-creeper out of a grape-vine.

A large class of plants are beggars and thieves. This is a hard thing to
say of them, but, what would you call them when they press their roots
into the bark of other plants and suck their sap, which is the same to
the plant as life-blood? Why can't they dig in the soil for themselves?
Some of these plants wear fine clothes, and look innocent enough. There
is the beautiful yellow fox-glove. Many times I have seen it, tall and
showy on hill-sides and in woods. But they were root-parasites, that is,
fastened by their roots on the roots of other plants, sucking juices
dishonestly. The delicate purple gerardia sometimes does the same thing.
So, you see, appearances are deceptive, and in plants, as well as
people, you cannot always tell charact