This perennial can grow to be 4 feet tall and just as wide. It grows best in full sun, and is tolerant of a wide range of soil conditions. Its beautiful blue flowers emerge in late spring through early summer.  It attracts a wide range of pollinators as well as being a host for many butterflies and moths, including the beautiful Orange Sulphur.
 
Rare, but native to the mountains of NC. Click to see its range in North Carolina.
 
More info here