(L.) King & H.E. Robins.
Identity
Unique IDELEMENT_GLOBAL.2.131913
Element CodePDASTBX0D0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusAgeratina
Other Common NamesEupatoire rugueuse (FR) white snakeroot (EN)
Concept ReferenceKartesz, 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 CommentsThis record is for the broad treatment of Ageratina altissima, including A. altissima var. roanensis as a variety, as recognized by Kartesz (1994, 1999) and FNA (2006, vol. 21). Weakley et al. (2023) exclude A. roanensis as a distinct species. FNA's (2006) treatment includes Ageratina altissima var. angustata in A. altissima var. altissima while Kartesz (1999) treats these as distinct.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-08-07
Change Date1990-03-07
Edition Date2024-08-07
Edition AuthorsN. Ventrella (2024)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank ReasonsAgeratina altissima is a perennial herb occurring in moist forests, cove forests, forests of northern red oak, and oak-chestnut, sucessional and disturbed forests, and in old fields of eastern and central North America from Ontario east to Nova Scotia, Canada, south to Florida, west to Texas, and north to North Dakota in the United States. There are over 4,000 estimated occurrences of this species range-wide, which are potentially threatened by development, rights-of-way maintenance, and invasive species. Little is known about threats or trends, but with a large range extent and large number of occurrences, Ageratina altissima is considered secure.
Range Extent CommentsAgeratina altissima occurs in eastern and central North America from Ontario east to Nova Scotia, Canada, south to Florida, west to Texas, and north to North Dakota in the United States (FNA 2006). Range extent was estimated to be over 3.9 million square kilometers using herbarium specimens and photo-based observations documented between 2022 and 2024 (GBIF 2024, iNaturalist 2024, SEINet 2024). See individual entries for distribution details about the two varieties.
Occurrences CommentsBy applying a 1 km separation distance to herbarium records and photo-based observations documented between 2022 and 2024, there are estimated to be over 4,000 occurrences rangewide (GBIF 2024, iNaturalist 2024, SEINet 2024).
Threat Impact CommentsAlthough threats are not widely documented, Ageratina altissima is potentially threatened by development, rights-of-way maintenance, invasive species, and other threats in some places. However, their overall impact is likely negligible given the species' broad range, large number of occurrences, tolerance of light disturbance, and affinity for typically abundant habitats, as well as no obvious intrinsic vulnerabilities.