pokeweed plant, with green fruit, showing sepals, against morning sun
The title about covers it, I guess. These fruits are about the size of a green pea. I just happened to be going by this plant, and thought I'd point and shoot, and this is the result.
This is the same plant as in the previous photo, and I'm going to use part of the same description. Something had built a web in among the fruit, it seems. Note that the stem is starting to turn purple.
Pokeweeds are wild plants -- there are a lot of them growing in Upstate South Carolina, and I've never seen one in a flower or vegetable garden.
Pokeweed, genus Phytolacca, is an interesting plant, quite common in this area. They grow up to a couple of meters/yards in height, and have characteristic red/purple stems. In the fall, the leaves turn reddish purple, too. The plant was used as a dye by Native Americans, and has been used as a medicine. The plant is poisonous, but edible (really!). See the Wikipedia article on pokeweed for more information.
For other photos of this plant, see our Pokeweed set.