Blue-purple colored petals on grass type plant, in open pine wood grass land, which is sometimes wet.
Not sure. Aripeka Sandhills Preserve, Florida, USA
Disappointing photo. Unclear if it is opposite or alternative. Not confident in ID, but using Centrosema as a placeholder.
had white flowers in the summer
They've stopped flowering, but they had white flowers. There are lots of seed pods. Finding the several plants is going to be a lot more difficult now that they aren't flowering anymore, since their leaves blend in very well...
AI suggested
assuming. One of several with white flowers in the area. Observed this individual multiple times, this is the first flower for this year :)