I found this yellow flower along with several others in an area in the forest surrounded by ferns. I had trouble deciding on whether it was a partridge pea or two-leaved senna, but after looking closely and finding the brown part in the center of the flower, it looks as if it is a partridge pea.
Chamaecrista fasciculata (Partridge Pea) is a species of legume native to most of the eastern United States. It is an annual which grows to approximately 0.5 meters tall. It has bright yellow flowers from early summer until first frost, with flowers through the entire flowering season if rainfall is sufficient.