Home/Species/ Lesser Snakeroot

Ageratina aromatica

(L.) Spach

Lesser Snakeroot

G5Secure Found in 2 roadless areas NatureServe Explorer →

G5SecureGlobal Rank

UnknownThreat Impact

Identity

Unique IDELEMENT_GLOBAL.2.132479

Element CodePDASTBX0C0

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVascular Plant

Endemicendemic to a single nation

KingdomPlantae

PhylumAnthophyta

ClassDicotyledoneae

OrderAsterales

FamilyAsteraceae

GenusAgeratina

Synonyms

Eupatorium aromaticumL.

Other Common Names

lesser snakeroot (EN)

Concept Reference

Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

Taxonomic Comments

Kartesz (1994, 1999) recognizes two varieties of Ageratina aromatica, the widespread var. aromaticum, and var. incisum, known only from Florida and Virginia. Flora of North America Editorial Committee (2006) and Weakley (2023) do not recognize infrataxa in A. aromatica.

Conservation Status

Rank Method Rank calculation - Biotics v2

Review Date2023-10-16

Change Date2000-12-31

Edition Date2023-10-16

Edition AuthorsTomaino, A. (2023)

Threat ImpactUnknown

Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)

Number of Occurrences> 300

Rank Reasons

Ageratina aromatica is known from the eastern U.S., from Massachusetts and Ohio, south to Louisiana and northern Florida. It is regionally rare in the northern part of its range. There are estimated to be over 300 occurrences. Threats, particularly in the northern part of its range include invasive plants, road and trail maintenance, grazing by deer, fire suppression, and shading by woody species as a result of succession.

Range Extent Comments

Ageratina aromatica is known from eastern Massachusetts and southeastern New York, to Ohio, Kentucky, and south to Louisiana and northern Florida (FNA 2006, NYNHP 2023, Weakley and the Southeastern Flora Team 2023). Range extent was estimated using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1992 and 2023 (GBIF 2023, iNaturalist 2023, NatureServe 2023).

Occurrences Comments

Ageratina aromatica is rare in the northeastern U.S. and relatively common in the southern southeastern U.S. (Craine 2003, Weakley and the Southeastern Flora Team 2023). By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1992 and 2023, it is estimated that there are over 300 occurrences rangewide (GBIF 2023, iNaturalist 2023, NatureServe 2023).

Threat Impact Comments

Threats to Ageratina aromatica include invasive plants, road and trail maintenance, grazing by deer, fire suppression, and shading by woody species as a result of succession (Craine 2003, NatureServe 2023, NYNHP 2023).

Ecology & Habitat

Habitat

In New England, habitat is dry, open woods, primarily on south-facing, rocky hillsides or at the bases of rock ledges, usually in relatively sunny spots within oak-hickory forests (Craine 2003). In the southeast U.S., Ageratina aromatica occurs in woodlands and forests, usually xeric, and often fire-maintained, longleaf pine sandhills, also woodland edges (Weakley 2023). Flora of North America (2006) mentions sandy soils, burned pinelands, turkey oak sand ridges, pine-oak and oak-hickory upland woods, old fields, roadsides, and fencerows.

Terrestrial Habitats

Forest/WoodlandForest - HardwoodForest EdgeWoodland - HardwoodWoodland - MixedSavannaOld field

Other Nations (1)

United StatesN5

Province	Rank	Native
Rhode Island	SNR	Yes
Tennessee	SNR	Yes
North Carolina	S5	Yes
Florida	S4	Yes
Massachusetts	S1	Yes
Pennsylvania	S2	Yes
New Jersey	S1	Yes
Louisiana	SNR	Yes
Connecticut	S1	Yes
Kentucky	SNR	Yes
District of Columbia	SNR	Yes
South Carolina	S5	Yes
Georgia	S5	Yes
Delaware	SU	Yes
New York	S1	Yes
Maryland	SNR	Yes
Alabama	SNR	Yes
Virginia	S4	Yes
Mississippi	SNR	Yes
Ohio	S1	Yes
West Virginia	S1	Yes

Threat Assessments

Threat	Scope	Severity	Timing
4 - Transportation & service corridors	Unknown	Unknown	Unknown
4.1 - Roads & railroads	Unknown	Unknown	Unknown
6 - Human intrusions & disturbance	Unknown	Unknown	Unknown
6.1 - Recreational activities	Unknown	Unknown	Unknown
7 - Natural system modifications	Unknown	Unknown	Unknown
7.1 - Fire & fire suppression	Unknown	Unknown	Unknown
8 - Invasive & other problematic species, genes & diseases	Unknown	Unknown	Unknown
8.1 - Invasive non-native/alien species/diseases	Unknown	Unknown	Unknown
8.2 - Problematic native species/diseases	Unknown	Unknown	Unknown

Plant Characteristics

DurationPERENNIAL

Economic Value (Genus)No

Roadless Areas (2)

Alabama (1)

Area	Forest	Acres
Cheaha B	Talladega National Forest	741

North Carolina (1)

Area	Forest	Acres
Cherry Cove (addition)	Nantahala National Forest	836

References (7)

Craine, S.I. 2003. Ageratina aromatica (L.) Spach Lesser Snakeroot Conservation and Research Plan for New England Wildflower Society, Framingham, MA. 31 pp.
Flora of North America Editorial Committee (FNA). 2006c. Flora of North America north of Mexico. Vol. 21. Magnoliophyta: Asteridae, part 8: Asteraceae, part 3. Oxford Univ. Press, New York. xxii + 616 pp.
Johnson, E.A. 2025. Ageratina aromatica Rare Plant Profile. New Jersey Department of Environmental Protection, State Parks, Forests & Historic Sites, Forests & Natural Lands, Office of Natural Lands Management, New Jersey Natural Heritage Program, Trenton, NJ. 16 pp. [https://dep.nj.gov/wp-content/uploads/parksandforests/ageratina-aromatica-smaller-white-snakeroot.pdf]
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
New York Natural Heritage Program. 2023. Online Conservation Guide for Ageratina aromatica var. aromatica. Online. Available: https://guides.nynhp.org/small-white-snakeroot/ (Accessed 2023).
Weakley, A.S., and Southeastern Flora Team. 2023. Flora of the southeastern United States. Edition of April 14, 2023. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. 2105 pp.

Ageratina aromatica

Habitat

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