This tall spindly blue wildflower is growing in one of our mowed hay fields, alongside Sheep Sorrel, Old Field Toadflax, two Krigia species, Cudweed, and Fleabane.
actually, this is not a native plant, but was introduced from Asia, probably Japan. It is the southern rockbell, Wahlenbergia marginata, and is fairly common locally along roadsides. It is in the bellflower family, Campanulaceae. You can find a few more pictures and more about it here: http://florida.plantatlas.usf.edu/Plant.aspx?id=226
Dr. Steven R. Hill, Botanist, SCNPS