North Carolina Botanical Garden

Plant Index

Scientific Name:
Common Name:
Genus:
Family:

Pycnanthemum flexuosum

Pycnanthemum flexuosum (Walter) Britton, Sterns & Poggenb.

appalachian mountainmint, savanna mountain-mint

Synonym(s): Koellia hugeri, Koellia hyssopifolia, Pycnanthemum hyssopifolium

Pycnanthemum flexuosum (Appalachian Mountainmint)

Image ID: 19594
Image by: Stuart, Will
Image Collection: NCBG Digital Library

PLANT INDEX

ID_PLANT: PYFL
SCIENTIFIC NAME: Pycnanthemum flexuosum
Include in WOTAS: 1
Publish to Web: 1
Last Modified: 2018-01-24

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 of moist to wet pine savannas, pocosin margins, mountain bogs and seepage areas on low-elevation granite domes.
STEMS: Stems 4-angled, branched (ascending) above, covered with white hairs.
LEAVES: Leaves opposite, petiolate, narrowly oblong to lance-shaped, with 3-5 pairs of parallel veins starting at or below middle of blade, sometimes with a few marginal teeth, smooth or hairy on veins beneath and with a faint mint-like odor.
INFLORESCENCE:
FLOWERS: Flowers in flattened-round terminal and axillary heads with a bristly appearance; each flower white and purple-spotted, to Â¼ in. long, tubular and opening to 2 spreading lips. The tubular calyx has 5 lobes with needlelike, long white tips.
FRUITS:
COMMENTS:
HEIGHT: 1-3 1/2 ft.

DURATION: Perennial
HABIT: Herb

LEAF ARRANGEMENT: Opposite
LEAF COMPLEXITY: Simple
LEAF RETENTION:

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

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

BLOOM COLOR: White

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

FRUITING PERIOD: Sep-Oct.

DISTRIBUTION
HABITAT TYPE: Bogs/pocosins, Outcrops and glades, Pine savannas
NATIVE RANGE: southeastern United States

HORTICULTURAL
Plant Sale Text: Appalachian Mountainmint tends to be more compact than most members of the Pycnanthemum genus. This is an easy-to-grow southeastern native perennial with delightfully scented foliage that is not normally eaten by deer. It produces small white flowers over its handsome green foliage, and attracts many beneficial pollinators. Appalachian Mountainmint tends to spread moderately over time, once the plant is established. While moderately vigorous, it does grow well with other species. The leaves of this species provide food for caterpillars of the Gray Hairstreak butterfly.

Bloom Table Text:

NCBG Location:

Cultural Notes:

SOIL MOISTURE: Dry, Average, Moist/Wet
LIGHT EXPOSURE: Sun, Part Shade
MINIMUM HARDINESS ZONE: 5
MAXIMUM HARDINESS ZONE: 8
GERMINATION CODE:
WILDLIFE VALUE: Bee Friendly, Butterfly Friendly
DEER RESISTANCE:

GRIM COLLECTIONS

Coll_id	Project	Collection date	Collector	Action
73	HORT	2007-08-31	Walker	View
931	SOS	2017-08-30	Faucette	View
2574	NPMD	2021-11-03	Pil	View
2588	NPMD	2021-12-01	Pil	View
2718	NPMD	2022-10-06	Kunz	View
2796	NPMD	2023-10-18	Hofmann	View

GRIM ACCESSIONS

acc_id	acc_num	acc_dt	coll_id	Action
70	2013-0019	2013-07-01	73	View
2004	1986-1797			View

GRIM PLANTINGS

plt_num	acc_id	loc_num	pers_num	inst_dt	Action
90	70	64	Liloia	2013-06-18	View
3228	2004	63	NCBG staff	1986-12-23	View

USDA PLANTS DATABASE

USDA Symbol: PYFL
USDA Common Name: Appalachian Mountainmint
Native Status: L48 (N)
Distribution: USA (AL, FL, GA, MS, NC, SC, VA)
Duration: Perennial
Growth Habit: Forb/herb

NATIONAL WETLAND INDICATOR STATUS

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

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

2018 Natural Heritage Program List of Rare Plant Species of North Carolina

NHP ID	S RANK	ROUNDED S RANK	G RANK	ROUNDED G RANK	STATE STATUS	FEDERAL STATUS
17992	S5	S5	G5	G5	W6

This information is derived from the 2018 North Carolina Natural Heritage Program List of Rare Plant Species.

WEAKLEY FLORA

SCIENTIFIC NAME: Pycnanthemum flexuosum
COMMON NAME: Savanna Mountain-mint
SYNONYMY: [= C, F, K, RAB, Va, W, WH3, Y; = P. hyssopifolium Bentham - G, GW, Z; > Koellia hyssopifolia (Bentham) Britton - S; > Koellia hugeri Small - S]
PHENOLOGY: Jun-Sep; Sep-Oct.
HABITAT: Moist to wet pine savannas, pocosin margins, mountain bogs, seepage areas on low elevation granite domes.
COMMENTS: Se. VA south to ne. FL, west to Panhandle FL and s. MS (Sorrie & LeBlond 2008) on the Coastal Plain; disjunct inland in bogs and rock outcrops of sw. NC with Coastal Plain affinities and in sc. TN. A diploid species (n = 18). Sometimes mistaken in vegetative condition for Eupatorium leucolepis, P. flexuosum can be distinguished by its square stem and aromatic odor. Koellia hugeri Small, alleged to differ details of the calyx, was established for the plants of bogs of the Blue Ridge; it apparently is not morphologically segregated from other variation within the species (Grant & Epling 1943).
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 flexuosum in Southeast Regional Network of Experts and Collections (if available)
UNC SERNEC: Find Pycnanthemum flexuosum in University of North Carolina Chapel Hill Herbarium - Southeast Regional Network of Experts and Collections (if available)

WEB RESOURCES

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

IMAGE USE RECORDS

ID IMAGE: 19594 - Primary Image FloraQuest Plant Detail Page (Landscape Preferred)
ID IMAGE1: 19592 - Primary Image WOTAS
ID IMAGE2: 0 - Secondary Image WOTAS
ID IMAGE3: 19592 - Primary Image Plant Sale Sign (Landscape Only)
ID IMAGE4: 0 - Primary Image New Plant Sale Label (Portrait Only)