At the top of the picture at the left I've removed the corolla so you can see how the filaments join at the base into a cylinder surrounding the pistil. The top example shows the white style passing upward among the ten stamens' slender filaments which, by the way, are diadelphous, as defined on our our Bean Flower Page.
The middle image at the left shows a flower in which the anthers' pollen has been shed, the pistil has been pollinated, and now the pistil is enlarging, pushing the corolla away.
At the bottom the corolla now is shriveled, brown, and about to fall away, and the pistil is beginning to look like a green bean. It is about ¾-inch long (2 cm).
Below is a mature green bean 6.5 inches long (17 cm). Notice how I've removed part of one side of the bean revealing three seeds, or beans. This fruit is a classic legume, which, on our Simple Dry Fruits Page, we've said "develop from one-carpel ovaries, but they split along two sides, not one, as in the case of follicles."