Pycnanthemum muticum Troy Weldy

Pycnanthemum muticum
Troy Weldy

Dicotyledoneae (Dicots)
Lamiaceae (Mint Family)
State Protection
Federal Protection
Not Listed
State Conservation Status Rank
Global Conservation Status Rank


Did you know?

Butterflies favor this plant because it is a good source of nectar. (Pycnanthemum muticum in American Beauties Native Plants fact sheet, accessed 16 November 2007). The leaves have a strong mint fragrance that can even be smelled in museum specimens decades old.

State Ranking Justification

There are 11 existing populations but most of them have fewer than 50 plants. There are about 10 historical records but many of these are from developed areas from New York City to Long Island and around Rochester. More populations could be found as its habitat preferences are better understood.

Short-term Trends

More survey work is needed to understand the short-term trends since most populations have only been surveyed once.

Long-term Trends

Most of the original historical records are from areas that have been developed but new populations have been discovered to keep the total number of populations about the same over time.

Conservation and Management


For plants located close to the road any construction from the road may negatively impact the population if the road crew is not made aware of its presence. More studies are needed to determine if run-off from the road is a threat. Other populations are located close to human activity which may inadvertently harm plants.

Conservation Strategies and Management Practices

Avoid mowing plants along roadsides during the growing season. Establish sufficient buffers around populations to preserve the undisturbed aspect and hydrology of their habitat.

Research Needs

Research is needed to determine what is limiting the spread of this species since there seems to be plenty of habitat into which it could grow.



In New York most of our extant sites for Pycnanthemum muticum consist of wet, sandy, coastal habitats. These include wet swales between dunes, the shores of coastal plain ponds, red-maple-sweetgum swamps, and wet roadside shrub thickets. There is also a single extant site inland along a railroad embankment (New York Natural Heritage Program 2007). Moist woods, thickets, meadows, and swales (Rhoads and Block 2000). Moist woods and meadows (Gleason and Cronquist 1991). Dry (or somewhat wet) woods, thickets, and clearings (Fernald 1970).

Associated Ecological Communities

  • Brackish interdunal swales (guide)
  • Hempstead Plains grassland* (guide)
  • Maritime dunes* (guide)
  • Maritime grassland (guide)
  • Maritime shrubland (guide)
  • Mowed roadside/pathway
  • Pastureland*
  • Red maple-sweetgum swamp (guide)
  • Successional maritime forest* (guide)
  • Successional old field*
  • Successional shrubland*
  • Unpaved road/path*

Associated Species

  • Amelanchier canadensis
  • Andropogon gerardii
  • Arctostaphylos uva-ursi (bearberry)
  • Asclepias incarnata
  • Chrysopsis mariana (Maryland golden-aster)
  • Clethra alnifolia (coastal sweet-pepperbush)
  • Euthamia graminifolia (common flat-topped-goldenrod)
  • Eutrochium purpureum
  • Hibiscus moscheutos
  • Juncus tenuis (path rush)
  • Lyonia ligustrina
  • Lysimachia terrestris (swamp-candles)
  • Osmunda cinnamomea
  • Parthenocissus quinquefolia (Virginia-creeper)
  • Photinia pyrifolia
  • Phragmites australis (old world reed grass, old world phragmites)
  • Prunella vulgaris
  • Rhododendron viscosum (swamp azalea)
  • Scirpus atrovirens (dark-green bulrush)
  • Scirpus cyperinus (common wool-grass)
  • Solidago odora (sweet goldenrod)
  • Solidago rugosa
  • spaghnum
  • Spiraea tomentosa (steeplebush)
  • Thelypteris palustris
  • Toxicodendron radicans
  • Triadenum virginicum
  • Vaccinium corymbosum (highbush blueberry)
  • Vaccinium macrocarpon (cranberry)
  • Verbena hastata (blue vervain)


New York State Distribution

Most of the extant New York populations are located on the South Fork of eastern Long Island. There is also one current record Staten Island and one from Orange County. There are historical records scattered elsewhere in Western New York and up the Hudson Valley to Washington County.

Global Distribution

Pycnanthemum muticum is found in all the states east of the Mississippi, excepting Maine (from which it is believed to be extirpated), Indiana, and Wisconsin. It is also found in Texas, Louisiana, Arkansas, and Missouri.

Best Places to See

  • Hither Hills State Park (Suffolk County)

Identification Comments

General Description

Pycnanthemum muticum is a rhizomatous herb with a branching, pubescent, square stem up to 1 m tall. Like other Mountain-mints it is strongly aromatic, such that a strong spearmint odor from the leaves may be the explorer's first clue to its presence. A main field characteristic of Pycnanthemum muticum is its firm, thick, dark green leaves. These are broadly oval, with a pointed tip, and round or heart-shaped leaf bases. They range from 1 to 4 cm wide and are usually no more than twice as long as wide. The middle stem leaves are typically glabrous to waxy above, while the upper inflorescence leaves are velvety. The flowers are crowded in rounded heads at the top of the stems. They are 2-lipped, the petals are white or pale violet with many purple spots. The teeth of the calyx are all triangular to acuminate (long-pointed).

Best Life Stage for Proper Identification

Blunt Mountain-mint is best identified when flowering or fruiting.

Similar Species

In New York misidentifications of Pycnanthemum muticum usually turn out to be P.virginianum, P. verticillatum, or rarely P. incanum. Pycnanthemum virginianum and P. verticillatum typically have leaves at least 3 times as long as wide, and only rarely over 1.5 cm wide. Pycnanthemum muticum leaves are usually not more than 2 times as long as wide and range from 1 to 4 cm wide. Pycnanthemum incanum, as well as P. clinopodioides, have a bilabiate calyx, with the upper and lower calyx teeth of unequal lengths.

Best Time to See

This species flowers in mid-July to early September, with the fruits persisting through the first frost.

  • Flowering
  • Fruiting

The time of year you would expect to find Blunt Mountain Mint flowering and fruiting in New York.

Blunt Mountain Mint Images


Blunt Mountain Mint
Pycnanthemum muticum (Michx.) Pers.

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Dicotyledoneae (Dicots)
        • Order Lamiales
          • Family Lamiaceae (Mint Family)

Additional Common Names

  • Mountain-mint


  • Koellia mutica (Michx.) Britt.

Additional Resources

Best Identification Reference

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.

Other References

Clemants, Steven and Carol Gracie. 2006. Wildflowers in the Field and Forest. A Field Guide to the Northeastern United States. Oxford University Press, New York, NY. 445 pp.

Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.

Grant, Elizabeth and Carl Epling. 1943. A study of Pycnanthemum (Labiatae). University Of California Publications in Botany 20: 195-240.

Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.

New York Natural Heritage Program. 2010. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.

New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.

Newcomb, Lawrence. 1977. Newcomb's Wildflower Guide: An Ingenious New Key System for Quick, Positive Field Identification of the Wildflowers, Flowering Shrubs, and Vines of Northeastern and North-Central North America. Little, Brown and Company. Boston.

Rhoads, Ann F. and Timothy A. Block. 2000. The Plants of Pennsylvania, an Illustrated Manual. University of Pennsylvania Press, Philadelphia, PA.

Snyder, D.B. 1994. Additions, range extensions, reinstatements, and relocations in the New Jersey flora. Bartonia 58: 79-96.

Voss, Edward G. 1996. Michigan Flora Part III. Dicots Concluded (Pyrolaceae - Compositae). Cranbrook Institute of Science Bulletin 61 and University of Michigan Herbarium. 622 pp.

Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research University of South Florida]. New York Flora Association, Albany, New York

Weldy, Troy W. and David Werier. 2005. New York Flora Atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research. University of South Florida]. New York Flora Association, Albany, NY. Available on the web at (


About This Guide

Information for this guide was last updated on: December 22, 2008

Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Pycnanthemum muticum. Available from: Accessed March 20, 2019.

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