Explaining how reproduction of new plants from parts of a parent plant.
Plants that produce sexually with flowers can also reproduce asexually. In asexual reproduction there is only one parent plant involved. New plants can grow from the roots, stems and sometimes leaves of the parent plant. The reproduction of new plants from parts of a parent plant (other than the usual reproductive structures like flowers and spores) is called natural vegetative propagation.
New plants from stem. The stem has nodes, where leaves and buds are attached. Stem generally grow above the ground. But some plants have stems that grow underground. At first sight, they do not look like stems. But, on closer look, you will notice that like all other stems, they have nodes. So, they are called modified stems.
Onion is an example of a bulb. A bulb consists of a short stem base with one or more buds enclosed in many fleshy leaves, which store food. The upper part of the fleshy leaves is composed of the regular green and narrow leaves found above the ground. The short stem base can develop roots, and the bulb can grow into new plant. Lily and hyacinth are also bulbs. A corm is a thick stem base with scaly leaves at the nodes and contains stored food. This modified stem can develop buds and roots at the nodes and grow into new plants. Gladiola and begonia are some examples of corms. White potato (also called Irish potato) is an example of a tuber. A tuber is enlarged because of stored food. The “eyes” of potato are its nodes. It a piece of the potato with “eyes” is planted, buds and roots will appear there and grow into new plants.
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Ginger is an example of rhizome. Rhizome is an underground stem that grows horizontally near the soil surface. It is fleshy because of stored food. Buds and roots develop at the nodes and grow into new plants. Strawberry and Bermuda grass are examples of runners, also called stolons. These are stems that grow horizontally above the ground, along the surface. When a node touches the ground, roots and leaves develop and a new plant grows. The stored food of a modified stem is used by the new plant in the early part of its life. Remember that leaves do not appear and manufactured food right away.