In riparian areas of canyons throughout the Southwest, the bigtooth maple (Acer grandidentatum) is a common sight. In fall their leaves turn a beautiful red-orange color.
You’re probably familiar with the samara, which is the winged fruit of the maple. This is a double samara, because each half contains one seed. Notice the intricate pattern of veins on the wings of the fruit. It shouldn’t surprise you that the veins look like those found in a leaf. This is because of the limited resources evolution can draw upon for the generation of new features. The samara’s wings are actually derived from the wall of the ovary, and an ovary’s evolutionary origin is the leaf (via the carpel). So it makes sense that the same form is repeated, with modification, in multiple parts of the organism. Almost like a fugue!