Each part of the bean plant serves a purpose. A simple plant anatomy lesson can help you understand how your plant develops. From the roots to the bean itself, each part plays a role in sustaining the plant which in turn provides you with beans to eat.
Roots: Anchor and Feed
Bean plants develop a main root, the tap root, which heads straight down. It functions as an anchor, keeping the plant in place. The tap root also takes in nutrients and water from the soil. Along its length are small hair-like roots that aid in this function. Some it stores, the rest is passed on to the plant. It also supports the stem of the plant.
Seed Leaves: Food Source for Young Plant
The inner part of the bean seed contains the seed leaves or cotyledons. While the seed is germinating and the stem and roots are sprouting, it is the cotyledons are what provide food to the plant until it can make its own. AS the stem pushes up through the soil, the cotyledons are pulled up to the surface too. They are called seed leaves because they retain the shape of the leaves.
Stem: The Spine of the Plant
Bean plants need a sturdy support and that is provided by the stem. Some bean plants are short of stature reaching only 34 to 36 inches while others must tower to 6 and 7 feet. A sturdy stem is necessary as it provides the means of transporting nutrients and water up to the plant and food back down. Along the stem are nodes where either buds or leaves will emerge.
Leaves: Food-making Machines
Leaves are storage units for the nutrients and water taken in by the roots. These are used in the process of photosynthesis to make food for the plant. Leaves also take in carbon dioxide as well as release extra water the plant has taken in. The leaves are attached to the stem by their petioles – small stem-like structures.
Flowers: Reproductive Parts
Without the flowers, there would be no beans. Flower open and pollination occurs. Once that happens, the flower is no longer needed. The petals drop away and from the node, a tiny bean begins to emerge. With some varieties of beans, the plant will continue to produce flowers and beans throughout the warm weather. Other varieties produce just one batch of flowers and beans.
Beans: Seed Bearers
When the beans are fully developed, the pods are several inches long. For snap beans, the pods are three to four inches long and slender when harvested. For shell beans like pinto or kidney beans, the pods actually dry out and shrivel revealing the bulging beans inside. The pods are split and beans harvested from inside.
Why Do Bean Plants Vary in Height?
The Effects of Fertilizer on Bean Plants
The Causes of Leaf Wilting in Green Bean Plants
Ohio State University: Plant Parts, Structure and Function
Ohio State University: External Structure of a Vascular Bean Plant