The Chief Gardener picked up a red clover leaf, and pointed to a little thin pale-green husk where the stem joined the main stalk.
"Those are stipules," he said. "In the clover they grow together, as one. The stipules are a part of the outside of the leaf-bud. When the bud opens, and the leaf goes out into the world, the stipules stay behind. Sometimes they are like little leaves, and take up air for the plant, just as the leaves do. Sometimes they almost take the place of leaves, and are quite large. Sometimes they are very tiny, and some plants have no stipules at all."
"THERE IS A LOT OF KINDS AND SHAPES"
"But leaves have veins, too," said Davy.
"Those are parts of the blade. The blade has ribs—they make a framework which holds it together; also veins—the fine threads which help to carry the sap. You see, plants are a good deal like ourselves, and live much in the same way. Some leaves have only one strong rib through the center—a sort of a backbone. Some have as many as six or seven."
They talked about these things, and looked at the different leaves and stems. Then they spoke of the stalks of different plants, and the Chief Gardener explained how the tender stalk of the lowliest plant, that of the tall twining vine, and the trunk of the giant oak, were all one and the same, only different in kind. Each came at some time from a tiny seed. Each put forth buds and leaves and branches. Each was made to withstand the storm—the oak by its strength, the vine by its fast hold on the wall or lattice, the tender plant through its lowliness.
"Oh," said Davy suddenly, "that makes me think of something. Our Virginia creeper on the front lattice has three ways to climb."
"What are they, Davy?"
"Why, it twists, for one way."