L.
Identity
Unique IDELEMENT_GLOBAL.2.134071
Element CodePDAST4N020
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusHelianthus
Other Common NamesNarrowleaf Sunflower (EN) swamp sunflower (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.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-11-03
Change Date1985-04-05
Edition Date2025-11-03
Edition AuthorsSoteropoulos (2025)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank ReasonsHelianthus angustifolius is a wide-ranging perennial herb found in a variety of mostly open, usually moist habitats, including pine savannas, ditches, and marshes. It is endemic to the eastern United States, primarily in the coastal plain from Long Island, New York south to Florida and west to Texas and Oklahoma, irregularly inland to Ohio, Indiana, and Missouri. There are over 2000 estimated occurrences, which face threats from development, conversion to agriculture or pasture, rights-of-way maintenance, recreational activities, fire suppression leading to succession, hydrological alteration, invasive species, and other threats in some places. Little is known about trends, but with a large range extent and large number of occurrences, abundant habitat, and broad habitat preferences, this species is considered secure.
Range Extent CommentsHelianthus angustifolius is endemic to the eastern United States, primarily in the coastal plain from Long Island, New York south to central peninsular Florida and west to eastern portions of Texas and Oklahoma, irregularly inland to Ohio, Indiana, and Missouri (FNA 2006, Weakley and the Southeastern Flora Team 2025). Range extent was estimated to be over 2.6 million square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Occurrences CommentsBy applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are over 2000 occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact CommentsAlthough threats are not widely documented, this species is threatened by development, conversion to agriculture or pasture, rights-of-way maintenance, recreational activities (especially off-road vehicles), fire suppression leading to succession, hydrological alteration, invasive species, and other threats in some places, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species (NatureServe 2025). 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.