Parts of a Flower Bean

Bean Seed

• All bean plants grow from a single bean seed. These seeds contain spongy innards that become food for the seed embryo when it germinates and strikes out its first root. As the root grows, the seed splits apart vertically into two equal pieces. If you dissect a seed, you'll be able to peel away the very thin outer skin and see a slight crevice running around the edge of the seed. This crevice cracks open when the seed germinates.

Roots

• Within a few days of planting, the roots strike out of the top of the bean seed and grow downward into the soil, curving down and away from the top of the seed in an upside-down U shape. The first root is called a sprout. It's white and tender. As the root grows, it strikes out with lateral roots or smaller roots that project from the main root. The lateral roots then sprout small, hair-like roots called terminal roots. These little hairs draw in nutrients.

Stem and Cotyledon

• In a bean seed, the root and stem don't grow out of opposite ends of the seed. Instead, the uppermost part of the root becomes the stem. As the roots continue to strike down into the soil, the top of the root still connected to the seed lifts the seed up out of the soil, creating the stem. The aerial, split seed is now called a cotyledon. Inside the two fleshy sides of the cotyledon are the first leaves of the plant.

Leaf and Flower Production

• Leaves fold out of the cotyledon and spread. As the leaves gather light, the cotyledon falls away into the soil. The stem grows and the leaves spread out into sprouts growing along the sides of the main stem called lateral stems. At the tips of these stems, small buds form that bloom into flowers.

  Flowers consist of petals that surround the stamen and pistil of a flower, or the reproductive parts. At the tip of each stamen is an anther, a little fuzzy bulb covered in pollen. When the pollen touches the sticky tip of the vase-shaped pistil, it travels down into the flower's ovary and begins forming seeds.

Bean Formation

• As the seeds form in the flowers' ovaries, the petals begin to close. The sepals, or tiny leaves under the petals, grow longer and thicker. The flower loses its color and turns green as it forms slowly into a long bean pod with several beans inside. When the pods are totally ripe, they burst open and scatter the hard beans all over the ground, beginning the growing cycle again.