Also treated as Pycnanthemum verticillatum var. pilosum.
Soft hairs cover the stems and leaves of this aromatic perennial. Its small, spotted flowers gather into pale heads above a branching summer plant.
Hairy Mountain Mint field photograph. Select a photo to enlarge.
Family: Lamiaceae · mint family
Life cycle: Perennial
Height: About 2–4 feet
Bloom: Mid- to late summer
Habitat: Prairies, savannas, open woods, woodland edges and thickets
Light: Sun to partial shade
Origin: Native to central and eastern North America
Reported sightings may include cultivated plants.
Look for opposite, lance-shaped leaves and a conspicuous covering of soft hairs. The square stems are hairy on their flat faces as well as their corners; the leaves are hairy too.
Leaf edges have a fine fringe of hairs. Compact flower heads gather at the branch tips. Photograph the stem surface and both sides of a leaf to capture the most useful clues.
Search sunny prairies, savannas and open woodland edges during mid- to late summer. Hairy Mountain Mint occurs in dry-mesic to moist settings and often grows in patches. In Illinois it is most frequent in the central part of the state and is less common toward the north.
Native to parts of central and eastern North America, including Illinois. This guide uses the familiar name Pycnanthemum pilosum; Kew recognizes the same taxon as Pycnanthemum verticillatum var. pilosum.
Reported U.S. distribution
AR, CT, DE, IA, IL, IN, KS, KY, MA, MD, ME, MI, MO, MS, NE, NJ, NY, OH, OK, PA, RI, TN, VT, WV
State records describe documented distribution, not presence in every county. A state record alone does not establish that every population there is native. Distribution source: NC State Extension, under Pycnanthemum verticillatum var. pilosum.
Explore reported observations on iNaturalist ↗
Observation maps may include planted specimens and do not define the complete native range.
The small white flowers often carry purple speckles. Many flowers crowd into each head above narrow, hairy bracts.
The flower clusters can resemble those of other mountain mints. The hairy stems and foliage provide the stronger distinguishing clues.
Flowers overlap in appearance. Compare leaf width, leaf surfaces and where the stem hairs grow. These field photographs show overall foliage; use a hand lens or a close stem photograph for fine hairs.
Pycnanthemum tenuifolium
Very narrow, usually hairless leaves; stems normally smooth. A few hairs can occasionally occur along the stem corners.
Pycnanthemum virginianum
Generally broader leaves with smooth upper surfaces. Short stem hairs are concentrated chiefly along the corners.
Pycnanthemum pilosum
Soft hairs cover the leaves and both the corners and flat faces of the stems. Examine several leaves and a stem closely.
Bees, wasps, flies and butterflies visit the nectar-rich flowers. Watch a patch for several minutes to see different visitors use the same heads.
Underground rhizomes produce nearby shoots, allowing a perennial clump to expand. The branching stems and developing heads give the patch structure even before peak bloom.
Explore the other mountain mints, then practice recognizing Hairy Mountain Mint and other wildflowers in the quiz.
