Persimmon trees, Diospyros virginiana, are common trees throughout the eastern US south of a line from about southern New York to eastern Kansas.
Typically Persimmon trees are either male or female, and of course only the females bear fruit -- which are quite tasty if fully ripe but mind-boggelingly puckery otherwise!
In the photo at the top of the page you see a cluster of male flowers at the top, and a single female flower at the bottom, right. Note that the male flowers are smaller and appear in small clusters, while the larger female flower appears alone. The female flower is 7/16 inch high (1 cm)
Besides the fact that Persimmons have separate male and female flowers, they differ from our Standard Blossom by having an urn-shaped corolla with small lobes that curl backwards. Also, notice that the male flowers have typical calyces, but the female's calyx is very large and thick. As the pistil grows and matures into a Persimmon fruit, the calyx enlarges tremendously and becomes semi-woody, as shown at the left. In typical flowers, the calyx shrivels up or remains small and inconspicuous.
Above, you see the above flowers opened on one side. Notice how the pollen-producing stamens inside the male flower nearly fill the corolla. Inside the female flower, the pistil with its four styles looks about like you'd expect, but also notice that there appear to be stamens leaning over the ovary. They are indeed stamens, though they are noticeably smaller than those in the male flower. The stamens in a Persimmon's female flowers are usually sterile. The interesting word here is "usually," for rarely the stamens in such female flowers do produce pollen, so rarely a tree with female flowers can produce fruit without another tree with male flowers being around!