“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.”
Plants with Underground Stems
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