| The plant: The living plant; The root |
|Different kinds of roots|
• The roots of a maize plant, a millet plant and a rice plant are alike.
• The roots of a mango tree, an orange tree and a lemon tree are alike.
• The roots of maize, millet and rice are not like those of the mango tree, the orange tree and the lemon tree.
• Different plants have different roots.
Some plants have small, thin roots, all of the same length.
• These roots form a tuft, as for instance the roots of onion, rice, millet, maize.
• A plant that has many small roots of the same length, the same thickness, the same shape, has fibrous roots.
Some plants have roots that are shallow and long.
• Creeping roots do not go deep into the soil.
• These roots go a long way from the base of the plant.
They cover a large area.
They have to find in a small depth of earth the food necessary for the life of the plant.
Many trees have creeping roots.
• A plant that has shallow, very long roots has creeping roots.
Some plants have only one root, very thick, deep, straight, called a tap- root.
• Smaller roots grow on this thick root; they are called rootless.
• Tap-roots go deep into the soil.
They cannot penetrate soil that is too hard.
• Cotton, coffee, cocoa, okra, carrots, papayas all have a root that goes deep into the soil, is very thick and straight.
They have a tap- root.
Some plants have very thick roots.
• These roots store up food.
• These roots are thick because they have taken up a lot of food from the soil.
The food is stored up in order to feed the whole plant.
The plant is said to have built up reserves.
For example, cassava.
• A plant that stores up reserves in thick roots has tuberous roots.
In some plants roots start from the stem above the soil, that is, above the collar, and afterwards go down into the earth.
• Adventitious roots grow above the collar.
For example, mangrove, bamboo, maize and rice all have adventitious roots.
• Soil put around the collar helps adventitious roots to grow; the plant is earthed up.
• A plant with roots on the stems has adventitious roots.