Last October I wrote about some wild cucumbers (Echinocystis lobata, Cucurbitaceae) that I found here in a southeast Michigan floodplain forest. This past October I found them again in the same place, and took advantage of better lighting to get some better pictures of the fruit. In the photo above the one on the left was the least mature. It was a fully-developed, green spiny fruit, but hadn’t yet opened. The one in the lower right was farther along. You can see how the bottom peeled open to eject the seeds. The one in the upper right was farther along still. It had finished releasing its seeds and had turned brown.
This photo is a better close-up of a mature, unopened fruit. These plants grow across most of North America, and if you happen to stumble across one in the autumn they really get your attention. Even in the summer before they fruit, you can recognize them by their somewhat distinct leaves and twining, viney growth.