A member of the Mint family (Lamiaceae), Nettleleaf Sage (Salvia urticifolia) is an herbaceous perennial that is native to the southeastern United States, with some found in Pennsylvania which is the northernmost part of its range.
It grows to 1 ½-2 feet tall, with square stems of green, that are pubescent. Leaves are opposite on short petioles.
Nettleleaf Sage grows in open woods and forest edges. Those forest edges are where I find it with its blue and white, purple and white or all white blooms.
A joy to discover.