Part 14

“Well done, Dolly!” said her uncle proudly. “Now, I think we have quite enough to go on with. Let us take these up one by one and examine and draw parts of them. First take the wood anemone. What do you call this?”

Uncle George pointed to the stout part of the plant that had been in the ground.

“The root,” said Frank.

“No, Frank!” his uncle replied. “But that is what I thought you would say. Now, tell us why you think it is the root.”

“Because it grows under ground.”

“But roots do not have buds upon them, Frank: and see! flower-stalk and leaf-stalk spring from it, while fibrous, or string like, roots hang down from it.”

“It must be a stem, then,” Frank ventured.

“It is the stem,” said his uncle. “We have already seen that the creeping crowfoot and ground ivy have stems that creep along on the surface of the ground.

“Many plants have stems which creep along under ground. This is an underground stem; and this is another.” Here he pointed to the primrose.

“Why, I always thought that that pink thing was the root of the primrose,” said Frank; “but I see now that it is really more like a stem. It has marks upon it like scars.”

1. Caterpillar, Pupa, and perfect Insect of Tiger Moth 2. Caterpillar, Pupa, and perfect Insect of Magpie Moth 3. White (Cabbage) Butterfly, Male and Female, with Caterpillar and Pupa

“These are marks where leaves once grew upon it,” his uncle remarked. “Notice that the primrose leaves form a rosette on the top of this underground stem.”

“Is there any reason for these plants having their stems under ground?” Tom asked.

“There is a reason for everything in nature, my boy. Can’t you see any reason for this yourself?”

“I see one, I think,” said Frank; “it enables the plant to creep out to new soil.”

“That is one very good reason, Frank. Now, why should it seek other soil?”

“For food!”

“That is right, Frank. Those plants which have underground stems seem to die down every autumn; but they are alive all the time under ground, safe from the frosts and bitter winds which kill tender plants. And they peep up in a new place in spring.

“Now I want you to tell me why these underground stems are swollen out so. It cannot be for strength, for creeping stems don’t require to be strong.

“Fetch me a raw potato, Tom, please!

“Now,” Uncle George continued, “tell me what this potato is.”

“It is an underground stem,” said Frank.

“Yes! Why is it swollen? What do we use the potato for?”

“For food. Oh, I know,” said Frank, “it is a food store.”

“Of course,” said his uncle. “It is a supply of food gathered up this year for next year’s plant. Look at the roots of the lesser celandine. I see Tom has drawn them. They are swollen. Are they roots, or underground stems?”

“They have neither leaf marks on them, nor buds,” said Frank, “I think they must be roots.”

“They are roots,” said Uncle George, “but they are food supplies all the same.

“There are other underground stems that grow quickly. Good examples of these are mint, couch grass, and sand sedge. The underground stems of these plants grow so fast that they are always occupying new ground. They have therefore no need to store up a food supply like their slower growing neighbours the primrose, potato, anemone, iris, and many others.”