The square stems are erect or ascending with opposite leaves. Both the stems and leaves are variably hairy or fuzzy.
Flowers occur in dense, axillary clusters.
The petals are white to light purple or pink. Flowers have four stamens and are in bloom from July through September. This common mint occurs in sedge meadows, calcareous fens , shrub-carrs, alder thickets, shallow marshes, and along streams and shores.