This cute little annual can quickly grow to be 20" tall. Growing best in full sun to part shade, it can tolerate a wide range of soil conditions. From wet to dry, acidic to neutral pH, and various soil composition. The small yellow flowers attract pollinators June through September. The seeds quickly form after and are eaten by song birds. Many caterpillars  host on this plant, including sulphur butterflies. It is a nitrogen fixer and easily self seeds. The unique leaves close up when touched. 
 
Native to nearly every county in NC. Click to view its range in North Carolina. 
 
More info here.