North Carolina Botanical Garden

Plant Index

Scientific Name:
Common Name:
Genus:
Family:

Pycnanthemum tenuifolium

Pycnanthemum tenuifolium Schrad.

narrow-leaf mountain-mint, slender mountain-mint

Synonym(s): Koellia flexuosa, Pycnanthemum flexuosum

Pycnanthemum tenuifolium (Narrow-leaf Mountain-mint)

Image ID: 18554
Image by: Ware, Richard & Teresa
Image Collection: NCBG Digital Library

PLANT INDEX

ID_PLANT: PYTE
SCIENTIFIC NAME: Pycnanthemum tenuifolium
Include in WOTAS: 1
Publish to Web: 1
Last Modified: 2019-03-15

GENUS INDEX

GENUS CODE: PYCNA
GENUS SCIENTIFIC: Pycnanthemum
GENUS AUTHORITY: Michx.
GENUS COMMON: Mountainmint
GENUS SUMMARY: A genus of 20-25 species, herbs, of temperate North America. Pycnanthemum remains a complicated and difficult group, with speciation apparently having proceeded by allopolyploidy, autoploidy, and aneuploidy. Numerous aberrant forms and (probably) sterile hybrids complicate identification and understanding.
GENUS IDENTIFICATION:
GENUS REFERENCES: Chambers (1993); Grant & Epling (1943)=Z; Chambers & Hamer (1992)=Y; Harley et al. in Kadereit (2004).

FAMILY INDEX

FAMILY CODE: LAMIAC
FAMILY SCIENTIFIC: Lamiaceae
FAMILY AUTHORITY: Lindley 1836 or LABIATAE A.L. de Jussieu 1789
FAMILY COMMON: Mint Family
FAMILY SUMMARY: A family of about 230-250 genera and 6700-7170 species, herbs, shrubs, vines, and trees, cosmopolitan. The placement in the Lamiaceae of several genera traditionally placed in Verbenaceae (e.g. Clerodendrum) is strongly supported by several lines of evidence.
FAMILY REFERENCE: Harley et al. in Kadereit (2004).

NCBG DESCRIPTIVES

INTRO: Erect, rhizomatous perennial found in bogs, wet meadows and moist to wet forests and clearings.
STEMS: Stems slender, 4-angled, bushy-branched, smooth.
LEAVES: Leaves opposite, mostly sessile, linear, to 2 in. long, gland-dotted and with mint-like odor.
INFLORESCENCE:
FLOWERS: Flowers crowded in dense, branching, flat-topped heads with small, white, hairy bracts in addition to flowers; each flower white to pale pink, less than Â¼ in. long, tubular opening to 2 spreading lips and with 2 purple anthers.
FRUITS:
COMMENTS:
HEIGHT: 1-2 1/2 ft.

DURATION: Perennial
HABIT: Herb

LEAF ARRANGEMENT: Opposite
LEAF COMPLEXITY: Simple
LEAF RETENTION:

FLORAL CHARACTERISTICS
SYMMETRY: Bilateral (Zygomorphic)
BLOOM TIME: June-Sep

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
				x	x	x	x	x

BLOOM COLOR: White

White	Red	Pink	Orange	Yellow	Green	Blue	Lavender	Purple	Violet	Brown	Not Applicable
x

FRUITING PERIOD: Sep-Oct.

DISTRIBUTION
HABITAT TYPE: Bogs/pocosins, Moist forests
NATIVE RANGE: eastern United States

HORTICULTURAL
Plant Sale Text: Narrow-leaf mountain-mint is an easy-to-grow southeastern native perennial with delightfully scented foliage. Just brush your hand lightly across the leaves to release the fresh minty fragrance. Narrow-leaf mountain-mint produces copious amounts of nectar, attracting and feeding many beneficial insects. Its upright stems bearing many small white flowers add an unusual cool touch to the summer garden, and make an excellent filler for flower arrangements.

Bloom Table Text: This plant is attractive to the eye as well as being a rich source of nectar to a multitude of insects and butterflies. The scientific name for the Mountain-mint comes from the greek, pyknos, meaning dense, and anthemon, a flower. It refers to the crowded clusters of flowers with small, leafy bracts immediately below them. Mountain-mints are erect, perennial, aromatic, herbaceous plants with rhizomes and branched or branchless, four-angled stems. These plants are often found in ordinary soil, neither excessively wet nor dry. They are planted in spring or early fall and will grow in sun or light shade. One can propagate the plant by division or seed.

NCBG Location: Education Center Landscape, Piedmont Habitat

Cultural Notes:

SOIL MOISTURE: Dry, Average, Moist/Wet
LIGHT EXPOSURE: Sun, Part Shade
MINIMUM HARDINESS ZONE: 3
MAXIMUM HARDINESS ZONE: 9
GERMINATION CODE: 1
WILDLIFE VALUE: Bee Friendly, Butterfly Friendly
DEER RESISTANCE:

GRIM COLLECTIONS

Coll_id	Project	Collection date	Collector	Action
284	HORT	2009-01-01	NCBG staff	View
320	HORT	2008-09-29	Liloia	View
769	SOS	2016-10-04	Walker	View
807	SOS	2016-10-21	Dakar	View
1232	HORT			View
1826	HORT	2006-10-01	Bryan	View
1854	HORT	2006-10-01	Bryan	View
2189	NPMD	2019-08-28	Touloupas	View
2212	NPMD	2019-09-09	Touloupas	View
2221	NPMD	2019-09-11	Touloupas	View
2251	NPMD	2019-09-24	Touloupas	View
2379	NPMD	2019-12-05	Touloupas	View
2647	NPMD	2022-09-14	Marzolf	View
2782	NPMD	2023-08-24	Marzolf	View

GRIM ACCESSIONS

acc_id	acc_num	acc_dt	coll_id	Action
279	2011-0135	2011-06-16	284	View
315	2011-0182	2011-07-12	320	View
2217	1986-2036			View
4330	1992-0486			View
5685	1995-0809			View
6260	1995-1392			View
6715	1996-0370			View
9062	2001-0220	2006-12-19	1232	View
9238	2014-0015	2020-05-08	0	View
9417	2021-0079	2021-06-29		View
9451	2021-0110	2021-07-13	0	View

GRIM PLANTINGS

plt_num	acc_id	loc_num	pers_num	inst_dt	Action
670	279	21	NCBG staff	2011-04-08	View
734	315	19	NCBG staff	2011-05-12	View
3851	2217	58	NCBG staff	1986-12-23	View
3852	2217	59	NCBG staff	0000-00-00	View
6658	4330	200	NCBG staff	1993-03-01	View
8199	5685	204	NCBG staff	1993-01-01	View
8915	6260	2	NCBG staff	0000-00-00	View
9483	6715	8	NCBG staff	1996-03-28	View
11079	9062	139	NCBG staff	0000-00-00	View
11080	9062	140	NCBG staff	0000-00-00	View
11081	9062	142	NCBG staff	0000-00-00	View
12356	9238	18	Liloia	2014-08-26	View
12652	9238	19	NCBG staff	0000-00-00	View
12730	9417	146	Wenck	2021-05-03	View
12766	0	23	Liloia	0000-00-00	View
12844	9451	21	Liloia	0000-00-00	View
13188	9417	37	Wait	2021-11-23	View
13195	9417	38	Wait	2021-11-23	View
14039	0	31	Wait	0000-00-00	View
14054	0	32	Wait	0000-00-00	View
14073	0	34	Wait	0000-00-00	View

USDA PLANTS DATABASE

USDA Symbol: PYTE
USDA Common Name: Narrowleaf Mountainmint
Native Status: L48 (N), CAN (N)
Distribution: USA (AL, AR, CT, DC, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, NE, NH, NJ, NY, OH, OK, PA, RI, SC, TN, TX, VA, VT, WI, WV), CAN (ON, QC)
Duration: Perennial
Growth Habit: Forb/herb

NATIONAL WETLAND INDICATOR STATUS

Region:	AGCP	AK	AW	CB	EMP	GP	HI	MW	NCNE	WMVE
Status:	FACW				FACW	FAC		FAC	FAC

This information is derived from the U.S. Army Corps of Engineers 2016 National Wetland Plant List, Version 3.3 (Lichvar, R.W., D.L. Banks, W.N. Kirchner, and N.C. Melvin. 2016. The National Wetland Plant List: 2016 wetland ratings. Phytoneuron 2016-30: 1-17. Published 28 April 2016. ISSN 2153 733X). Regions: AGCP-Atlantic and Gulf Coastal Plain, AK-Alaska, AW-Arid West, CB-Caribbean, EMP-Eastern Mountains and Piedmont, GP-Great Plains, HI-Hawaii, MW-Midwest, NCNE-Northcentral and Northeast, WMCV-Western Mountains, Valleys & Coast

WEAKLEY FLORA

SCIENTIFIC NAME: Pycnanthemum tenuifolium
COMMON NAME: Slender Mountain-mint
SYNONYMY: [= C, F, GW, K, Mo, Pa, RAB, Va, W, WH3, Y; = P. flexuosum - G, Z, misapplied; = Koellia flexuosa - S, misapplied]
PHENOLOGY: Jun-Aug; Sep-Oct.
HABITAT: Bogs, wet meadows, moist to wet forests.
COMMENTS: ME west to MN, KS, and OK, south to FL and TX. A diploid and tetraploid species (n = 20 and 40).
RANGE MAP:

Key to Map Symbols

ABOUT FAMILY (Weakley Flora)
Lamiaceae Lindley 1836 or LABIATAE A.L. de Jussieu 1789 (Mint Family)
SUMMARY: A family of about 230-250 genera and 6700-7170 species, herbs, shrubs, vines, and trees, cosmopolitan. The placement in the Lamiaceae of several genera traditionally placed in Verbenaceae (e.g. Clerodendrum) is strongly supported by several lines of evidence.
REFERENCE: Harley et al. in Kadereit (2004).

ABOUT GENUS (Weakley Flora)
Pycnanthemum Michx. (Mountainmint)
SUMMARY: A genus of 20-25 species, herbs, of temperate North America. Pycnanthemum remains a complicated and difficult group, with speciation apparently having proceeded by allopolyploidy, autoploidy, and aneuploidy. Numerous aberrant forms and (probably) sterile hybrids complicate identification and understanding.
REFERENCE: Chambers (1993); Grant & Epling (1943)=Z; Chambers & Hamer (1992)=Y; Harley et al. in Kadereit (2004).

HERBARIUM RESOURCES

SERNEC: Find Pycnanthemum tenuifolium in Southeast Regional Network of Experts and Collections (if available)
UNC SERNEC: Find Pycnanthemum tenuifolium in University of North Carolina Chapel Hill Herbarium - Southeast Regional Network of Experts and Collections (if available)

WEB RESOURCES

USDA: Find Pycnanthemum tenuifolium in USDA Plants
NPIN: Find Pycnanthemum tenuifolium in NPIN Database
FNA: Find Pycnanthemum tenuifolium in the Flora of North America (if available)
Google: Search Google for Pycnanthemum tenuifolium

IMAGE USE RECORDS

ID IMAGE: 18554 - Primary Image FloraQuest Plant Detail Page (Landscape Preferred)
ID IMAGE1: 18554 - Primary Image WOTAS
ID IMAGE2: 0 - Secondary Image WOTAS
ID IMAGE3: 18555 - Primary Image Plant Sale Sign (Landscape Only)
ID IMAGE4: 30147 - Primary Image New Plant Sale Label (Portrait Only)