Herbaceous perennial 1 to 3 feet tall and wide. Stem is square, characteristic of plants in the mint family. Leaves are very aromatic when crushed. Leaves and stems are covered in downy hairs. Plant is usually sterile.
Leaf blades egg-shaped to lance-shaped, generally peppermint- or spearmint-scented; flower cluster generally head-like, clustered at distal 3 to 5 nodes.
Habitat
Shaded riparian areas.
Flower Characteristics
The flowers are purple, less than 1/2 inch long, with a four-lobed corolla. They are produced in whorls around the stem and are largely concealed within the reddish-lilac corollas.
Leaf and Stem Characteristics
The leaves are from 1 to 1-1/2 inches long, dark green with reddish veins, with an acute apex and coarsely toothed margins. The leaves and stems are usually slightly fuzzy. Leaves contain menthol and are very aromatic.
Fruit and Seed Characteristics
As a hybrid, the plant is usually sterile, producing no seeds and reproducing only vegetatively, spreading by rhizomes.