Unopened flower buds of the prickly pear cactus. It looks like they'll open up and be pink, doesn't it?
Surprise! The prickly pear cactus blossoms open up green! -- and stay that way for a while, until . . . as you can see in this series of photos, they open fully and the outermost petals begin to tint a rosy shade that's still bears the pink of the petals' outsides.
Notice that in the first three images below, the flower's reproductive structures are still tightly folded. But in the fourth picture, the stamens have separated into a lush "bouquet" of pollen-bearing anthers. In the earlier pictures, the stigmas -- the thick rounded tube openings of the female reproductive structures are much larger than the stamens and a dark green on the end, so highly visible. But once the stamens spread out, they hide the stigmas somehwat. If you look closely, though, you can see the stigmas in end-on view in the image to the far right, including the dark slit in the center of each that is the hole through which pollen fertilizes the egg deep inside. (Hint as you look: there are four stigmas, side by side forming something of a square or diamond shape in the middle of the mass of stamens. Each pale green stigma end looks a bit like a donut. There is a dark green shadow between the four of them that stands out against the rest of the flower interior.)
The flower has matured and been pollinated. Its petals have gotten dark yellow in color and begin to close.
Now dying, the flower once again displays the pinkish-peach tones of its petals.
The dead flower withers, but the female reproductive structures deep beneath the stigmas have been pollinated, the eggs fertilized. Now a fruit grows, as yet unseen.
