GREEN BEAN FLOWERS
(also called stringbean, snapbean, or shell bean,
& grown as bush beans or pole beans -- it's Phaseolus vulgaris)
|The flower at the right is similar to the Kudzu flower
provided as a sample bean flower at our Bean Flower
Page, except that the image is taken from above, not the side. The camera was
right above the standard, which is the blossom's top petal. The two
petals projecting toward the right in the picture, thus constituting the flower's side
petals, are the two wings. A big difference between this bean flower and
the Kudzu flower is that the bean flower's keel -- the scoop-shaped
bottom petal (actually two petals grown together) -- is much smaller than the Kudzu
flower's keel, and the keel curls up and bends back into the flower's throat! This
"coiled keel" is the distinctive mark of the genus Phaseolus. In the
picture's center you can see the white, curved bottom of the keel curling up between the
two wings. (That's why the picture was taken from above.)
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."
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